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Antennas and Wireless Propagation Letters, IEEE

Popular Articles (April 2015)

Includes the top 50 most frequently downloaded documents for this publication according to the most recent monthly usage statistics.
  • 1. A Uniplanar Triple-Band Dipole Antenna Using Complementary Capacitively Loaded Loop

    Publication Year: 2015 , Page(s): 743 - 746
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (650 KB) |  | HTML iconHTML  

    A uniplanar compact metamaterial-inspired triple-band dipole antenna is designed and proposed for wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. By introducing two pairs of complementary capacitively loaded loop (CCLL) slots into a uniplanar bow-tie antenna, two notched bands can be generated to form a triple-band operation. The antenna is directly fed by a 50- Ω microstrip line and a microstrip-to-coplanar-stripline (CPS) transition as a wideband balun. Antenna parameters, including voltage standing-wave ratio (VSWR), radiation patterns, and gain, are obtained by numerical simulations and experimental measurements. The results show that the proposed antenna can provide triple-band operation at 2.21-2.77, 3.33-3.95, and 5.04-6 GHz with the VSWR less than 2 to achieve 2.4/5.2/5.8-GHz WLAN and 2.5/3.5/5.5-GHz WiMAX applications. View full abstract»

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  • 2. Novel Printed MIMO Antenna With Pattern and Polarization Diversity

    Publication Year: 2015 , Page(s): 739 - 742
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (766 KB) |  | HTML iconHTML  

    In this letter, a novel compact antenna system for diversity/multiple-input-multiple-output (MIMO) application is proposed for WLAN (5.8 GHz) band with good isolation between the two input ports. The novelty of the proposed MIMO antenna system is, though the resonators are physically separated by a distance of 0.029λ ( λ is the free-space wavelength at 5.8 GHz) equal to the thickness of the substrate (1.524 mm) used for the fabrication of the antenna system, the isolation between them is enough for practical application of the antenna for MIMO. The MIMO system possesses good pattern diversity and polarization diversity with good isolation without the use of any isolation enhancement techniques. Moreover, the concept can be extended to the realization of an MIMO antenna system to operate at other frequencies with suitable scaling and optimization of geometrical parameters of the antenna topology. View full abstract»

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  • 3. Multibroadband Slotted Bow-Tie Monopole Antenna

    Publication Year: 2015 , Page(s): 887 - 890
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (988 KB) |  | HTML iconHTML  

    In this letter, a coplanar waveguide (CPW)-fed multiband bow-tie monopole antenna is proposed. This antenna can be easily designed to meet the requirement of multiple operating frequencies by using the proposed approach. Multiple bent monopoles, which correspond to different operating frequencies, are generated by etching slots of different lengths in a bow-tie patch. The length of each bent monopole is determined under the quarter wavelength resonance condition. Each frequency band can be easily satisfied for the broadband character because the bow-tie patch can be treated as a broadband impedance-matching structure. This study demonstrates a triple-band slotted bow-tie monopole antenna for WLAN/WiMAX/LTE applications with bands of 2.4-2.7 GHz, 3.4-3.7 GHz, and 5.2-5.8 GHz. The size of the proposed antenna fabricated on a 0.8 mm-thick FR4 substrate with a dielectric constant of 4.2 without considering the ground plane size is only 19.5 ×9.0 mm2. The good agreement between the simulation results and the measurement validates the proposed design approach. View full abstract»

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  • 4. A Small-Size Dual-Feed Broadband Circularly Polarized U-Slot Patch Antenna

    Publication Year: 2015 , Page(s): 898 - 901
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1138 KB) |  | HTML iconHTML  

    A small-size broadband circularly polarized U-slot patch antenna with dual-feed is proposed. By introducing an additional feeding probe near the vertical slot of the conventional singly fed square U-slot patch antenna printed on a high-permittivity substrate, two series resonances in close proximity are excited. The two resonant frequencies are found to be independent of the orientation of U-slot with respect to the patch, and broadband circular polarization is achieved by introducing a nonquadrature phase difference between two feeding ports. Experimental results show that the overlapped bandwidth of VSWR ≤ 1.5 and AR ≤ 3 dB is over 20% with a small overall size of 0.33λ0 × 0.33λ0 × 0.068λ0, where λ0 is the free-space wavelength at the center frequency within the operating band. View full abstract»

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  • 5. Single- and Dual-Band Transparent Circularly Polarized Patch Antennas With Metamaterial Loading

    Publication Year: 2015 , Page(s): 470 - 473
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (760 KB) |  | HTML iconHTML  

    In this letter, we present circularly polarized (CP) patch antennas that achieve up to 70% optical transparency by using a wire-mesh patch and by cutting the same grid pattern through the substrate. Glass or quartz wafers are therefore not needed, and our antennas may be fabricated on standard ceramic substrates, reducing cost and simplifying construction. Metamaterial loading is incorporated in one patch to control the relative phase difference between the patch's orthogonal modes, which in turn produces dual-band CP radiation. Our dual-band transparent antenna operates at 2.35 and 2.73 GHz with peak radiation efficiencies of 70% and 78%, respectively. View full abstract»

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  • 6. Proximity-Coupled Microstrip Antenna for Bluetooth, WiMAX, and WLAN Applications

    Publication Year: 2015 , Page(s): 755 - 758
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1067 KB) |  | HTML iconHTML  

    This letter presents a novel proximity-coupled multiband microstrip patch antenna. The proposed antenna simultaneously operates at Bluetooth (2.4-2.485 GHz), WiMAX (3.3-3.7 GHz), and WLAN (5.15-5.35 and 5.725-5.85 GHz) bands with consistent radiation pattern and uniform gain. The antenna is a two-layer design. A V-shaped patch with a rectangular strip on the top layer is fed by a buried rectangular strip in the middle layer by proximity coupling. Furthermore, resonating parasitic structures in the bottom plane are used to improve the antenna characteristics. The fabricated antenna has a small size of 24 ×27 ×1.6 mm3 on an FR4 substrate. View full abstract»

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  • 7. A Compact Frequency-Reconfigurable Multiband LTE MIMO Antenna for Laptop Applications

    Publication Year: 2014 , Page(s): 1389 - 1392
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1046 KB) |  | HTML iconHTML  

    A compact frequency-reconfigurable multipleinput-multiple-output (MIMO) antenna on a laptop is proposed for multiband LTE services. Each MIMO antenna consists of two planar inverted-F antenna (PIFA) elements, using a T-shaped dc line and two p-i-n diodes (D1 and D2), in conjunction with the proximity-coupled feed structure. By effectively minimizing its dimension and its interference with antenna performance, the proposed T-shaped dc line is designed to fit within the proximity-coupled feed structure. The proposed MIMO antenna covers the LTE 17/13 bands (704-787 MHz, VSWR <; 3) at State 1 (D1 and D2: ON state), and the LTE 20/7 bands (791-862 MHz, 2500-2690 MHz, VSWR <; 3) at State 2 (D1 and D2: OFF state). The proposed antenna obtains high isolation (> 20 dB), low envelope correlation coefficient (ECC <; 0.0161), and total efficiency of greater than 51%, for all operating frequency bands. View full abstract»

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  • 8. MIMO Antennas for Mobile Handsets

    Publication Year: 2015 , Page(s): 799 - 802
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1428 KB)  

    This letter presents a pair of printed MIMO antennas for mobile handsets. With each antenna being a coupled fed monopole in a meandered shape, it is capable of covering GSM 1800/1900, UMTS, WLAN, and LTE frequency bands. The antennas are oriented diagonally at the nongrounded portion of the circuit board. The substrate used for the circuit board is FR4 with relative permittivity of 4.4 and loss tangent of 0.02. The overall volume of the circuit board is 110×65×0.8 mm3, with each antenna occupying an area of 24×14.5 mm2. To improve the isolation between antennas, dual decoupling structures consisting of ground slots and inverted L ground branches that extend into the nongrounded portion are etched diagonally on the bottom layer of the substrate. The isolation achieved is better than 15 dB over all the frequency bands covered by each antenna leading to an envelope correlation coefficient of less than 0.02. The simulation and measured results are in good agreement. View full abstract»

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  • 9. Decoupled Dual-Antenna System Using Crossed Neutralization Lines for LTE/WWAN Smartphone Applications

    Publication Year: 2015 , Page(s): 523 - 526
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (956 KB) |  | HTML iconHTML  

    A decoupled dual-antenna system for Long Term Evolution (LTE)/Wireless Wide Area Network (WWAN) smartphone applications is presented. The proposed dual-antenna system is composed of two symmetric antenna elements and two crossed neutralization lines. The antenna element of the proposed dual-antenna system consists of a driven branch and a parasitic ground branch, generating a couple of resonant modes. The dual-antenna system incorporates two crossed neutralization lines to reduce the mutual coupling between the two closely spaced antenna elements. A measured impedance bandwidth with S11 lower than -6 dB over 702-968, 1698-2216, and 2264-3000 MHz is obtained. Within the operating bands, the measured S21 is lower than 10 dB. Based on the measured 3-D radiation patterns, several important figures of merit for the diversity performance of the dual-antenna system are calculated, including the envelop correlation coefficient, the mean effective gain, and the diversity gain, and good results are obtained. View full abstract»

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  • 10. A Compact Broadband Dual-Polarized Patch Antenna for Satellite Communication/Navigation Applications

    Publication Year: 2015 , Page(s): 273 - 276
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (912 KB) |  | HTML iconHTML  

    In this letter, a compact and robust dual circularly polarized patch antenna for combined Globalstar/GPS application has been presented. The designed patch antenna is accomplished with size of 40 × 40 × 6 mm3 over the frequency bandwidth of 1570-1650 MHz, which is 0.21λ0 × 0.21λ0 × 0.03λ0 ( λ0 is the free-space wavelength at the lowest frequency of the operating bandwidth). Instead of air substrate, high-permittivity substrate is adopted for the size reduction. The bandwidth reduction due to the inclusion of the high-permittivity substrate is compensated by introducing a parasitic patch. In addition, a 90° hybrid is utilized for achieving dual circular polarization. The designed antenna is validated by the measurement, presenting a 5% fractional bandwidth (1570-1650 MHz) for both VSWR <; 2, axial ratio less than 3 dB, and port isolation less than -6 dB. View full abstract»

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  • 11. Stacked Open-Loop Square Ring Antenna for Circular Polarization Operation

    Publication Year: 2015 , Page(s): 835 - 838
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (818 KB) |  | HTML iconHTML  

    In this letter, a novel circular polarized (CP) open-loop square ring antenna using a stacked structure is proposed. The proposed antenna consists of two open-loop square ring resonators and a T-shaped feed structure. The resonant frequency of the ring resonator is adjusted mainly by changing the width of the ring. Depending on the location of the gap in the square ring, each open-loop square ring antenna exhibits different linear polarizations. By selecting a suitable ring width and gap position, two orthogonal resonant modes with equal amplitude and a 90 ° phase difference are excited, and good CP is achieved. The measured 10-dB reflection coefficient and 3-dB axial ratio bandwidth of the antenna prototype are 3.93% and 1.2%, respectively. View full abstract»

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  • 12. A Novel Low-Profile High-Gain UHF Antenna Using High-Impedance Surfaces

    Publication Year: 2015 , Page(s): 1014 - 1017
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (966 KB) |  | HTML iconHTML  

    A novel wideband low-profile planar antenna design based on the use of a high-impedance surface (HIS) is presented for digital television (DTV) reception in the UHF band. The proposed design is based on a wideband monopole antenna in close proximity to an artificial ground plane, composed of an array of square metal loops at the top, an air gap and a ground plane at the bottom, without grounded vias. Low-cost substrates are employed in the design: rigid PVC for the antenna and foamed PVC for the artificial ground plane. The advantages of the proposed design for DTV applications are high gain, low profile, light weight, low cost and large bandwidth. Details of the proposed antenna design are described, and measurements together with a comparison to a conventional antenna with PEC ground plane are presented. View full abstract»

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  • 13. A Compact Dual-Mode Metamaterial-Based Loop Antenna for Pattern Diversity

    Publication Year: 2015 , Page(s): 394 - 397
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (844 KB) |  | HTML iconHTML  

    This letter presents a novel design of compact dual-port dual-mode metamaterial-based loop antenna for pattern diversity. The proposed metamaterial-based loop antenna consists of a loop based on periodically loaded capacitive arc strips and two independent ports with feeding networks. Similar to mu-zero resonance (MZR) antennas, the periodically loaded capacitive loop antenna proposed in this letter allows current along the loop to remain in phase and uniform. By making use of a hybrid feed network, the even and odd modes of the proposed metamaterial-based loop antenna are exploited so that its pattern diversity is achieved effectively. The theory of operation and performances of the proposed antenna are demonstrated in both a full-wave simulation and in the experiments. View full abstract»

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  • 14. A Novel Antenna with Reconfigurable Patterns Using H-Shaped Structures

    Publication Year: 2015 , Page(s): 915 - 918
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (902 KB) |  | HTML iconHTML  

    A novel pattern reconfigurable antenna is proposed in this letter by introducing a unique finite periodic structure. The H-shaped units are precisely arranged on the both sides of the dipole to direct the power flowing in the end-fire direction. When the antenna operates with the PIN diodes between the units, different radiation patterns can be easily achieved by changing the states of these PIN diodes. The prototype of the pattern reconfigurable antenna with three patterns is fabricated and measured. The experimental results show that the end-fire mode of the antenna has a front-to-back ratio as high as 15 dB and the pattern reconfigurable capability is successfully achieved in the band of 2.47-2.9 GHz. View full abstract»

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  • 15. Multiband Metamaterial-Loaded Monopole Antenna for WLAN/WiMAX Applications

    Publication Year: 2015 , Page(s): 662 - 665
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1030 KB) |  | HTML iconHTML  

    A simple multiband metamaterial-loaded monopole antenna suitable for wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications is proposed in this letter. The rectangle monopole of the proposed antenna is originally designed to resonate at around 5.2 GHz. When the inverted-L slot is etched, the antenna produces a second resonance at around 4.1 GHz. Then, with the addition of the metamaterial reactive loading, the resonant frequency of the antenna will be shifted down, and a third resonance covering the 2.4-GHz band occurs. Consequently, the antenna can cover the 2.4/5.2/5.8-GHz WLAN and 2.5/3.5/5.5-GHz WiMAX bands with a very compact size of only 12.9 ×6.5 mm2. Monopole-like radiation patterns and acceptable gains and efficiencies have been obtained. Details of the antenna design as well as the experimental results are presented and discussed. View full abstract»

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  • 16. A Broadband and Electrically Small Planar Monopole Employing Metamaterial Transmission Line

    Publication Year: 2015 , Page(s): 1018 - 1021
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (762 KB)  

    A broadband and electrically small planar monopole is presented in this letter. In order to increase the impedance bandwidth, a metal patch embedded with two epsilon-negative meander lines is used as the main radiator and the ground plane is periodically etched with cross slots. The etched ground and the patch form a metamaterial transmission line (MTL) resonance, which not only miniaturizes the antenna but also improves its bandwidth. The proposed antenna can work in the frequency band of 2.38-2.95 GHz with a fractional bandwidth as much as 21.5%. The size of the main radiator is 0.078λ0 ×0.073λ0 and the maximum gain is 3.42 dBi. The antenna can be applied to various wireless mobile communication systems such as RFID, WLAN, and WiFi. View full abstract»

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  • 17. A High-Gain Dual-Band EBG Resonator Antenna with Circular Polarization

    Publication Year: 2015 , Page(s): 108 - 111
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (530 KB) |  | HTML iconHTML  

    A dual-band circularly polarized (CP) electromagnatic band-gap (EBG) resonator antenna (ERA) is presented. The antenna employs an all-dielectric superstructure, which consists of two identical unprinted dielectric slabs, and a dual-band corner-truncated patch feed. A prototype antenna is fabricated and tested using a superstructure made out of 3.175-mm-thick Rogers TMM10 material. Measured peak gains are 16.1 dBic [left-hand circular polarization (LHCP)] and 16.2 dBic [right-hand circular polarization (RHCP)], measured radiation efficiencies are 93% and 91%, and the boresight axial ratios are 1.9 and 1.5 dB at 9.65 and 11.75 GHz, respectively. This dual-band antenna is easy to fabricate, making it suitable for high-gain low-cost CP applications. View full abstract»

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  • 18. A Low-Profile and Wideband PILA-Based Antenna for Handset Diversity Applications

    Publication Year: 2015 , Page(s): 923 - 926
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1035 KB) |  | HTML iconHTML  

    A low-profile (5 mm) and wideband planar inverted-L antenna (PILA) is proposed for handset diversity and MIMO applications. It occupies a footprint area of 702 ( = 351 ×2) mm2 over the ground plane and consists of two elements arranged utilizing both pattern and spatial diversities to provide a reasonable isolation level. The radiators consist of modified PILAs coupled with a ground plane notch that works as a parasitic radiator; a small ground plane strip is added to shift the lower edge frequency down to 1700 MHz. The single-element and dual-element antennas are analyzed in terms of the reflection coefficient and antenna impedance. Prototypes are made and the measurement results show that this design is good for mobile applications over the frequency range 1700-2850 MHz with a fractional bandwidth of 51%; it covers applications such as DCS 1800, PCS 1900, UMTS, LTE 2300 and LTE 2500, Wi-Fi, and Bluetooth (2400-2448 MHz). Finally, the diversity performance parameters are obtained and evaluated based on both simulation and measurement results. It is demonstrated that the proposed antenna design is a promising candidate for wireless hand-portable applications. View full abstract»

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  • 19. A Novel Circularly Polarized Antenna With Coin-Shaped Patches and a Ring-Shaped Strip for Worldwide UHF RFID Applications

    Publication Year: 2015 , Page(s): 707 - 710
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (971 KB) |  | HTML iconHTML  

    A circularly polarized radio frequency identification (RFID) reader antenna is presented for worldwide ultra- high frequency (UHF) applications. The antenna is composed of two coin-shaped patches, a ring-shaped strip, and a suspended feeding strip with open-circuited termination. The measurements show that the antenna has an impedance bandwidth (S11 <;-21 dB) of 22.4% (768-962 MHz) and a stable gain with a peak value of 9.8 dBic. Moreover, it is immune to polarization mismatch with a 3-dB axial-ratio (AR) bandwidth of 15.9% (816-957 MHz) and a 3-dB AR beamwidth of more than 66°. The proposed antenna can be a candidate for universal RFID readers at the UHF band of 840-955 MHz. Due to the fact that the square holes in the center of the coin-shaped patches can embed one additional small antenna, the proposed antenna has the potential to be a dual- or tri-band combined RFID reader antenna, spanning both the conventional UHF and the ISM band of 2.45 or 5.8 GHz. View full abstract»

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  • 20. Millimeter-Wave Energy Harvesting Using 4\times4 Microstrip Patch Antenna Array

    Publication Year: 2015 , Page(s): 515 - 518
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1104 KB) |  | HTML iconHTML  

    In this letter, an energy harvester at 35 GHz has been developed, which known as a rectenna. An array of a rectangular microstrip patch antenna with 16 elements was used to efficiently convert RF to dc signal. A step-impedance low-pass filter is used between the antenna and rectifier circuit to suppress second-order harmonic generated by the diode. A GaAs Schottky diode MA4E1317 was used in parallel with load as a half-wave rectifier circuit. The fabrication process is based on conventional optical photolithography to obtain an integrated circuit. The maximum RF-to-dc conversion efficiency of 67% was successfully achieved with input RF power of 7 mW at 35.7 GHz. View full abstract»

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  • 21. A Compact Frequency-Reconfigurable Dielectric Resonator Antenna for LTE/WWAN and WLAN Applications

    Publication Year: 2015 , Page(s): 486 - 489
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (791 KB) |  | HTML iconHTML  

    A compact frequency-reconfigurable dielectric resonator antenna (DRA) for LTE/WWAN and WLAN applications is investigated and presented. The proposed antenna provides the frequency tuning between 1.60 and 2.71 GHz. The design consists of four identical rectangular dielectric resonators with permittivity of 10 each and three p-i-n diode switches that are located on the feedline network between each of two dielectric resonators. The proposed antenna size is 20 ×36 ×5.57 mm3, which is suitable for mobile devices. The measurement and simulation results are applied to demonstrate the performance of the proposed antenna. From the measured results, it is found that the proposed antenna with acceptable performance provides four single-band modes with the impedance bandwidths of 17%, 11%, 14%, and 6%. View full abstract»

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  • 22. A Circularly Polarized Antenna by Using Rotated-Stair Dielectric Resonator

    Publication Year: 2015 , Page(s): 787 - 790
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (989 KB) |  | HTML iconHTML  

    In this letter, a wideband compact circularly polarized (CP) dielectric resonator antenna (DRA) is proposed. This antenna consists of two rectangular dielectric layers that are stacked with a rotation angle φ relative to its adjacent bottom layer. The antenna is excited by an aperture coupled through a slot cutting on the ground plane. The rotated-stair configuration of DRA contributes dual broadside CP radiating modes and results in a noticeable enhancement in the axial ratio (AR) bandwidth. The proposed antenna achieves 31% impedance bandwidth and 18.2% AR bandwidth. The average gain within the AR bandwidth is 4.5 dBi with less than 0.5-dB variation. Moreover, the proposed dielectric resonator antenna has a low-profile structure. This work demonstrates a CP bandwidth broadening technique for the DRA. The potential applications of the antenna are 5G Wi-Fi and satellite communication systems. View full abstract»

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  • 23. A New Design Approach for Electrically Small High-Frequency Antennas

    Publication Year: 2015 , Page(s): 402 - 405
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (842 KB) |  | HTML iconHTML  

    The design of electrically small high-frequency (HF) wire antennas continues to be a challenging effort, primarily due to the tradeoffs involved in reducing antenna electrical size while attempting to maintain some level of acceptable impedance and bandwidth at lower frequencies. There are numerous examples of practical applications where antenna physical dimensions must be restricted. This letter presents a new concept in electrically small wire antenna design that seeks to address those real restrictions by providing new design methods for functional electrically small antennas when traditional methods fail. This new concept is based upon using the entire volume for antenna design. New designs are presented along with a comparison of performance characteristics obtained through simulation and experimentation. Significant improvements in performance using the proposed methodology are demonstrated, including increases in radiation resistance of up to 28% and reductions in Q of more than 20% as compared to antenna geometries with identical heights and volumes. View full abstract»

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  • 24. Slits Loaded Circularly Polarized Universal UHF RFID Reader Antenna

    Publication Year: 2015 , Page(s): 827 - 830
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (820 KB) |  | HTML iconHTML  

    A simple structure circularly polarized (CP) UHF (ultrahigh frequency) RFID (radio frequency identification) reader antenna that operates within the universal RFID bands (840-960 MHz) is investigated. Here, the technique of loading a corner truncated square patch antenna into an L-shaped ground plane is initially studied to achieve good impedance matching with broad CP bandwidth. To further enhance both the impedance bandwidth and CP bandwidth, a novel technique of loading three narrow slits into the corner truncated square patch is proposed. By meticulously arranging these three slits in a certain manner, from the experimental results, besides achieving a gain level of approximately 8.6 dBic, the proposed antenna can also yield an impedance bandwidth from 685 to 1125 MHz, while good CP bandwidth between 836 and 986 MHz is also demonstrated. View full abstract»

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  • 25. Design of Compact and High Directive Slot Antennas Using Grounded Metamaterial Slab

    Publication Year: 2015 , Page(s): 811 - 814
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (893 KB) |  | HTML iconHTML  

    In this letter, a simple and compact approach for directivity enhancement of slot antenna using a grounded metamaterial slab is proposed. This approach has been applied in two different configurations. In the first configuration, two dielectric layers are used for designing antenna and metamaterial slab. Despite the directivity enhancement, an improved bandwidth of about 10.74% is obtained for this configuration. It is also shown that, over the whole working band, a significant broadside directivity improvement is maintained compared to the unloaded slot. In the second configuration, only a single layer of dielectric is used for designing both antenna and metamaterial slab. Thus, in this case, the total thickness of the loaded antenna is noticeably reduced to 0.5 mm, or 0.014 λ0 at resonance. View full abstract»

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  • 26. A Novel Ultrawideband (UWB) Printed Antenna With a Dual Complementary Characteristic

    Publication Year: 2015 , Page(s): 974 - 977
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (860 KB)  

    A novel design concept for a versatile multi-functional coplanar waveguide (CPW)-fed ultrawideband (UWB) printed antenna is described in this letter. The antenna also exhibits a dual complementary characteristic of frequency notched response and narrowband response invoked by different combinative loading of a pair of split ring resonators (SRRs) and metallic shunt strips on the CPW feed line. The antenna restores its UWB response when the SRRs' split gaps are shorted. The simulated impedance and radiation characteristics are validated with measured results obtained using fabricated prototypes to establish the proof of concept. View full abstract»

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  • 27. A Compact Dual-Band GPS Antenna Design

    Publication Year: 2013 , Page(s): 245 - 248
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1017 KB) |  | HTML iconHTML  

    This letter discusses a small slot-loaded, proximity-fed patch antenna designed for GPS operation at L1 (1575 MHz) and L2 (1227 MHz) bands. High-dielectric substrate and meandered slots are employed to reduce the antenna size down to 25.4 mm in diameter and 11.27 mm in thickness. The thickness is important for achieving the wide bandwidth (>30 MHz) in support of modern GPS coding schemes. The dual-band coverage is achieved by utilizing the patch mode in L2 band and slot mode in L1 band. This design features additional slot stubs for independently tuning the L1 frequency. The right-hand circularly polarized (RHCP) field property is achieved by connecting two proximity probes to a small surface-mount 0°-90° hybrid chip. Simulated and measured antenna performance will be presented. This compact GPS antenna design is suitable for small GPS antenna arrays and portable GPS devices. View full abstract»

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  • 28. Miniaturized Dual-Band CPW-Fed Antennas Loaded With U-Shaped Metamaterials

    Publication Year: 2015 , Page(s): 658 - 661
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1052 KB) |  | HTML iconHTML  

    New dual band miniaturized planar antennas loaded with 4-cell metamaterial is presented. The structure of the antenna consists of a coplanar waveguide at input, microstrip line, patch, metamaterial loaded substrate under patch, and back conductor. For simpler construction procedure, U-shaped and inverted U-shaped metamaterial loaded substrate under the patch is made in two layers. At the first band, these antennas work as a wideband monopole antenna with about 35% miniaturization compared to the folded monopole antenna, and at the second band as a wideband patch antenna with about 77% miniaturization compared to the conventional patch antenna. View full abstract»

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  • 29. An Ultra Wideband to Dual Band Switchable Antenna Design for Wireless Communication Applications

    Publication Year: 2015 , Page(s): 1
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (820 KB)  

    A switchable planar monopole antenna operating in ultra-wide band and dual band mode is demonstrated. The switching is triggered with a photoconductive semiconductor switch triggered by light emitting diode. In the switched-off state, the antenna operates in the dual-band/UWB mode, while in the switch-on state the configuration converts to a dual band antenna due to the extended ground plane. The measured and simulated results show that the dual-band/UWB mode entirely covers the UWB frequency band and the 2.4 GHz wireless local area network WLAN, while the dual band mode represents a dual band antenna operating at WiMax and X-band Satellite communication bands. View full abstract»

    Open Access
  • 30. An LTE Base-Station Magnetoelectric Dipole Antenna with Anti-Interference Characteristics and Its MIMO System Application

    Publication Year: 2015 , Page(s): 906 - 909
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (893 KB) |  | HTML iconHTML  

    In this research, a wideband long-term evolution (LTE) base-station antenna with flexible band-notch characteristics is introduced by two window-type slots etched on radiation patches of the magnetoelectric dipole. The presented antenna can provide a band-notch range with an impedance bandwidth of 2.39-2.52 GHz in the band of 1.825-2.925 GHz, which well applies the wideband antenna for LTE with the good anti-interference from wireless local area network narrow communication band. The typical parameters are investigated to show that the antenna with anti-interference characteristics exhibits large scope band-notch adjustability in the whole wideband region. Based on above element, an LTE base station antenna multiple-input, multiple-output system with anti-interference characteristics is investigated and measured to show its good performances: anti-interference, high isolation, high gain, unidirectional radiation, low back radiation, and low cross-polarization. View full abstract»

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  • 31. Compact Low-Profile Dual Band Metamaterial Antenna for Body Centric Communications

    Publication Year: 2015 , Page(s): 863 - 866
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (717 KB) |  | HTML iconHTML  

    A compact low profile dual band metamaterial antenna is presented for wireless body centric communications. It is composed of a zeroth-order loop loaded periodically with mu-negative transmission line (MNG-TL) for a lower frequency band and a circular patch located in the center of loop for an upper frequency band. The MNG-TL loop based on the fundamental infinite wavelength property allows current along the loop to remain the same magnitude and phase to create omnidirectional radiation pattern in azimuth plane at the lower band for on-body communications. On the other hand, a unidirectional radiation pattern is generated by a circular patch in direction normal to a human body at the upper frequency band for off-body communications simultaneously. In order to feed the MNG-TL conveniently, a transition based on a CPW transmission line is proposed. Finally, the proposed antenna is fabricated and measured. It is demonstrated that the measurement has good agreement with simulation. View full abstract»

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  • 32. Low-RCS, High-Gain, and Wideband Mushroom Antenna

    Publication Year: 2015 , Page(s): 277 - 280
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1540 KB) |  | HTML iconHTML  

    In this letter, a high-gain and wideband mushroom antenna with wideband low radar cross section (RCS) is presented. The mushroom structure is resonant at the antenna operating frequency, and the in-band RCS can be reduced significantly. The bandstop frequency selective surface (FSS) designed at the operating frequency of the antenna is used to replace the metallic ground of the antenna so that the out-of-band RCS of the proposed antenna can be reduced while maintaining the high gain. Furthermore, square metallic patches printed periodically below the cells of the FSS are utilized to add a new zero-degree reflection phase in the desired frequency range to enhance the bandwidth of RCS reduction. As a result, a wideband RCS reduction can be achieved both in and out of antenna operating frequency band. The results show that the RCS of the proposed antenna is dramatically reduced over a wide frequency range, compared to the traditional patch antenna. View full abstract»

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  • 33. A New Broadband Single-Layer Dual-Band Reflectarray Antenna in X- and Ku-Bands

    Publication Year: 2015 , Page(s): 602 - 605
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1294 KB) |  | HTML iconHTML  

    A center-fed single-layer, dual-band reflectarray antenna is presented in this letter. Each element in this reflectarray antenna consists of a square ring and a patch, with slots on it. The proposed antenna operates in two bands (X and Ku), and it uses only one horn antenna as feed, in a fixed position. By varying the size of elements, the required phase shifts in X- and Ku-bands are obtained. Measurements show a maximum gain of 23.4 dB at 8.2 GHz with 33%, 3-dB bandwidth and 17%, 1-dB bandwidth and a maximum gain of 25.7 dB at 13.2 GHz with 30%, 3-dB bandwidth and 14%, 1-dB bandwidth. View full abstract»

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  • 34. Wideband Planar Four-Element Linear Antenna Array

    Publication Year: 2014 , Page(s): 1663 - 1666
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (776 KB) |  | HTML iconHTML  

    This letter presents a planar wideband linear antenna array to cover multiple wireless standards. The array consists of four microstripline-fed open-ended quarter-wavelength slot antenna elements. By feeding the antenna properly, a fundamental radiating antenna mode can be excited over a wide frequency range. The antenna array is simulated in terms of surface current distributions and S-parameters. Simulated results are compared to the manufactured prototype antenna array. Measured results show the -10-dB impedance bandwidth is from 2.55 to 6.1 GHz, corresponding to 83% relative impedance bandwidth, while mutual coupling is less than -16.6 dB within the aforementioned impedance bandwidth. The simulated -10-dB bandwidth is from 2.0 to 6.0 GHz. Measured radiation patterns are presented at 2.4, 3.5, and 5.2 GHz with 4.6, 7.0, and 7.9 dBi maximum gain in boresight direction, respectively. The measured radiation patterns and grating lobe levels correlate well with the theory and are 10-15 dB below the main lobe depending on the studied frequency. View full abstract»

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  • 35. Printed Meandering Probe-Fed Circularly Polarized Patch Antenna With Wide Bandwidth

    Publication Year: 2014 , Page(s): 654 - 657
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1018 KB) |  | HTML iconHTML  

    In this letter, a wideband compact circularly polarized (CP) patch antenna is proposed. This patch antenna consists of a printed meandering probe (M-probe) and truncated patches that excite orthogonal resonant modes to generate a wideband CP operation. The stacked patch is employed to further improve the axial-ratio (AR) bandwidth to fit the 5G Wi-Fi application. The proposed antenna achieves 42.3% impedance bandwidth and 16.8% AR bandwidth, respectively. The average gain within the AR bandwidth is 6.6 dBic with less than 0.5 dB variation. This work demonstrates a bandwidth broadening technique of an M-probe fed CP patch antenna. It is the first study to investigate and exhibit the M-probe could also provide the wideband characteristics in the dielectric loaded patch antenna. The potential applications of the antenna are 5G Wi-Fi and satellite communication systems. View full abstract»

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  • 36. Dual-Band and Dual-Polarized SIW-Fed Microstrip Patch Antenna

    Publication Year: 2014 , Page(s): 1605 - 1608
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB) |  | HTML iconHTML  

    A new dual-band and dual-polarized antenna is investigated in this letter. Two longitudinal and transverse slots on the broad wall of the substrate integrated waveguide (SIW) are responsible for creating two different frequency bands with distinct polarization. A frequency selective surface (FSS) is placed on top of the microstrip patches to reduce the cross-polarization level of the antenna. The resonance frequencies of the patch and slot are set near to each other to get a wider impedance bandwidth. Bandwidth of more than 7% is achieved in each band. SIW feeding network increases the efficiency of the antenna. The simulated radiation efficiency of the antenna is better than 87% over the impedance bandwidth . View full abstract»

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  • 37. A Compact Microstrip-Fed Triple Band-Notched UWB Monopole Antenna

    Publication Year: 2014 , Page(s): 396 - 399
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (937 KB) |  | HTML iconHTML  

    In this letter, a novel low-profile microstrip-fed compact triple band-notched ultrawideband (UWB) antenna is proposed. Notch bands around the 3.3-3.8-GHz WiMAX and 5.15-5.85-GHz WLAN frequencies are obtained by etching out two elliptic single complementary split-ring resonators (ESCSRRs) of different dimensions from the radiating patch of the antenna. Furthermore, by placing two rectangular split-ring resonators near the feedline-patch junction of the antenna, rejection for the 7.9-8.4-GHz X-band frequencies is achieved. Design guidelines for implementing the notch-bands at the desired frequency regions are provided. The match between the simulated and experimental results suggests that the proposed antenna can be a good candidate for application in UWB communication systems. View full abstract»

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  • 38. An Efficient Decoupling Feeding Network for Microstrip Antenna Array

    Publication Year: 2015 , Page(s): 871 - 874
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (741 KB) |  | HTML iconHTML  

    An efficient decoupling feeding network is proposed in this letter. It is composed of two directional couplers and two sections of transmission line for connection use. By connecting the two couplers, an indirect coupling with controlled magnitude and phase is introduced, which can be used to cancel out the direct coupling caused by space waves and surface waves between array elements. To demonstrate the method, a two-element microstrip antenna array with the proposed network has been designed, fabricated and measured. Both simulated and measured results have simultaneously proved that the proposed method presents excellent decoupling performance. The measured mutual coupling can be reduced to below -58 dB at center frequency. Meanwhile it has little influence on return loss and radiation patterns. The decoupling mechanism is simple and straightforward which can be easily applied in phased array antennas and MIMO systems. View full abstract»

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  • 39. The Time-Domain Optical Theorem in Antenna Theory

    Publication Year: 2015 , Page(s): 895 - 897
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (676 KB) |  | HTML iconHTML  

    A special form of the time-domain optical theorem related to a general receiving antenna system is rigorously derived. It is shown that the total energies dissipated in the antenna load and in the antenna system itself can be directly related to the electromagnetic energy of the scattered field and its time-domain far-field characteristics. A practical implication of the result in optimizing antenna scattering properties with regard to the maximum energy dissipated in the antenna loading is discussed. View full abstract»

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  • 40. An Equivalent Circuit Model of FSS-Based Metamaterial Absorber Using Coupled Line Theory

    Publication Year: 2015 , Page(s): 511 - 514
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (809 KB) |  | HTML iconHTML  

    An equivalent circuit model of an ultra-thin metamaterial absorber comprising a square-ring-shaped frequency selective surface (FSS) is presented. The model can be considered as series RLC resonators connected in parallel with coupling capacitance and short-circuited transmission line. The even- and odd-mode couplings have been incorporated to accurately determine the lumped parameters as well as the absorption frequency of the absorber structure. The effects of substrate thickness and dielectric permittivity variation on the lumped parameters and full width at half-maximum (FWHM) bandwidth are investigated based on the proposed model. The absorber has been fabricated, and close matching among the calculated, simulated, and measured results has been observed. View full abstract»

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  • 41. Inverted-F/Slot Integrated Dual-Band Four-Antenna System for WLAN Access Points

    Publication Year: 2015 , Page(s): 847 - 850
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (875 KB) |  | HTML iconHTML  

    A four-antenna system applicable to compact access points of wireless local area network is proposed. The antenna topology integrates an inverted-F antenna and a folded slot antenna in the same space to reduce sizes to 15.5 mm × 7.5 mm. The inverted-F antenna operates in the 5 GHz HiperLAN band and the slot functions in the 2.4 GHz ISM band. Antenna tuning can be done without difficulty because the two are of different antenna types. Four antenna assemblies are placed at corners of a 50 mm × 50 mm board to meet the multi-input multi-output operation needs. Since the element antenna exhibits moderate directivity and the four antennas are arranged in a rotational symmetry, decent isolations are achieved in both operation bands without additional decoupling measures. The antenna structure is fully planar and can be integrated within the printed circuit board, which makes it an attractive candidate for compact access point uses. View full abstract»

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  • 42. A Low-Profile and High-Permittivity Dielectric Resonator Antenna With Enhanced Bandwidth

    Publication Year: 2015 , Page(s): 791 - 794
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (774 KB) |  | HTML iconHTML  

    A dielectric resonator antenna of very high permittivity has been proposed. The antenna is designed based on a multilayered structure. To realize low profile and relatively large impedance bandwidth simultaneously, two separate dielectric resonators of high permittivity are placed symmetrically on top of the antenna structure. A low-permittivity dielectric substrate is inserted between the resonators and the ground. The total height of the antenna is 1.57 mm or 0.039λ (λ is the wavelength at the center frequency.) An enhanced bandwidth of 10.49% has been realized. The proposed antenna has stable radiation patterns across the whole operating band. Relatively high antenna gains over 6 dBi and a low cross-polarization level of -25 dB are also achieved. View full abstract»

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  • 43. A Compact 2.45-GHz Broadband Rectenna Using Grounded Coplanar Waveguide

    Publication Year: 2015 , Page(s): 986 - 989
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (765 KB) |  | HTML iconHTML  

    This letter presents a compact 2.45 GHz broadband rectenna using the grounded coplanar waveguide (GCPW). A new broadband slot antenna fed by GCPW with a high gain of 10 dBi and a wide half-power beamwidth of 60 ^{\circ} is designed as the receiving antenna. By designing an input and an output impedance match network, a compact GCPW rectifying circuit based on the voltage doubler principle is proposed, which has broadband performance and is easy to be integrated with the novel GCPW antenna. The receiving antenna and the rectifying circuit are simulated and measured. The measured results of the rectenna agree well with those of the rectifying circuit, which validate the effectiveness of the design. The microwave-direct current (mw-dc) conversion efficiencies of the rectenna keep higher than 50% within the band from 2.2  to 2.6 GHz at 13 dBm received power on a 900\Omega load, and the highest efficiency is 72.5%. This rectenna has good performances of broadband, high mw-dc efficiency and compact structure. View full abstract»

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  • 44. A Broadband Dipole Antenna for Multiservice Indoor Distributed Antenna System (MS-IDAS)

    Publication Year: 2015 , Page(s): 839 - 842
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1099 KB) |  | HTML iconHTML  

    Multiservice indoor distributed antenna system (MS-IDAS) plays an important role in wireless communications. This letter investigates a broadband antenna for MS-IDAS, which is composed of a loop-loaded dipole, a microstrip feeding line, and a flat reflector. Through the loop-loaded structure, the low frequency band is greatly extended. A prototype with dimensions of 180 mm ×150 mm ×50 mm is presented to cover the frequency band of 880-2700 MHz. Indoor coverage experiments prove that high quality signals are provided by the antenna within the designed bandwidth, which is a decent candidate for MS-IDAS. View full abstract»

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  • 45. Gain-Enhanced SIW Cavity-Backed Slot Antenna with Arbitrary Levels of Inclined Polarization

    Publication Year: 2015 , Page(s): 931 - 934
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1106 KB) |  | HTML iconHTML  

    This letter describes a gain enhancement method for a dual-polarized substrate integrated waveguide cavity-backed slot antenna by using a high-order cavity resonance to generate arbitrary levels of inclined linear polarization (LP). To do so, the metal posts are embedded in a main cavity to excite the TM220 mode of the cavity and control the amount of coupling to generate adjustable inclined linear polarization. To validate the simulated results, an antenna is designed, manufactured, and tested. The proposed antenna exhibits high front-to-back ratio (F/B) of more than 20 dB in the broadside direction and a relative gain of 6.9 dBi at the resonant frequency. The antenna can also provide an adjustable inclined LP with an aspect ratio of Exmax/Eymax ranging from 0.23 to 4. The proposed method can also be utilized to achieve even higher gain by exciting higher order mode cavity resonances, such as TM440 and TM660. The proposed antenna exhibits the advantages of simple feed network and more compactness compared with the SIW cavity-backed slot antenna/array that has the same gain with inclined polarization. View full abstract»

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  • 46. Dual-Band CP Antenna With a Dual-Ring Cavity for Enhanced Beamwidth

    Publication Year: 2015 , Page(s): 867 - 870
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (910 KB) |  | HTML iconHTML  

    A dual-band circularly polarized (CP) antenna with enhanced beamwidth is proposed in this letter. Stacked cone-patches including a small patch for upper band (1561 ± 2 MHz) and a large one for lower band (1268 ± 10 MHz) are used to achieve the dual-band operation behavior. To widen beamwidth for the two operation bands, a dual-ring cavity is employed for the proposed antenna. The dual-ring cavity is formed by a large ring and a small ring, which are used to improving the beam performance for lower and upper band, respectively. Over the dual-band of interests, the impedance bandwidth (VSWR ≤ 1.5) and the axial ratio below 3 dB are both satisfied. Wide 3 dB beamwidths of about 135 ° and 112 ° at center frequencies (1268, 1561 MHz) of the two bands are obtained, respectively. The high gains at the low elevation (θ = 80°), only about -0.03 dB and -0.57 dB at the two frequency points, are also achieved. With these good performances, the antenna is very suitable for navigation systems applications. View full abstract»

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  • 47. Compact Zigzag-Shaped-Slit Microstrip Antenna With Circular Defected Ground Structure for Wireless Applications

    Publication Year: 2015 , Page(s): 678 - 681
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1176 KB) |  | HTML iconHTML  

    In this letter, a compact zigzag-shaped-slit rectangular microstrip patch antenna with circular defected ground structure (DGS) is designed for wireless applications. The probe-fed antenna consisting of a zigzag-shaped slit, dual T-shaped slits on either sides of a rectangular patch, and circular dumbbell-shaped defected ground plane is optimized. The antenna was able to generate three separate resonances to cover both the 2.45/5.28-GHz WLAN bands and the 3.5-GHz WiMAX bands while maintaining a small overall size of 40 ×28 ×3.175 mm3. The return-loss impedance bandwidth values are enhanced significantly for three resonant frequencies. The designed antenna is characterized with better radiation patterns and potentially stable gain around 4-6 dBi over the working bands. Good agreement was obtained between measurements and simulations. View full abstract»

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  • 48. Small Wideband Monopole Antenna With a Distributed Inductive Strip for LTE/GSM/UMTS

    Publication Year: 2015 , Page(s): 1
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (901 KB)  

    We present a small, planar, and dual-wideband antenna for handheld devices, which consists of a driven spiral monopole and a distributed inductive strip designed. A dual-wideband characteristic is realized by using a coupling feed, a distributed inductor, and a folded strip, which excite multiple resonant modes to achieve wide impedance matching. The antenna size is reduced by spiraling of the monopole and meandering and folding of the distributed inductive strip, which occupies 20 × 15 mm2. The measured antenna gains and efficiencies are over 0.75 to 1.80 dBi and 60 to 82%, respectively. Radiation patterns are approximately omnidirectional in the x-y (H) planes for all bands: the LTE800, GSM850/900, GSM1800/1900, UMTS, and LTE2300/2500 bands. View full abstract»

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  • 49. Electronically Reconfigurable Uniplanar Antenna With Polarization Diversity for Cognitive Radio Applications

    Publication Year: 2015 , Page(s): 213 - 216
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (898 KB) |  | HTML iconHTML  

    A uniplanar, polarization diversity antenna with wideband/narrowband (WB/NB) switching capability is presented. The design utilizes an open annular slot with an orthogonal feeding mechanism to achieve polarization diversity performance across the operating bands. To attain high isolation between the ports, a strip is incorporated in the ground plane. Electronically reconfigurable slot resonator-based filters are also precisely embedded in the feedlines for the WB/NB switching. A fully functional prototype was fabricated, and the results were validated. The antenna provides a wide bandwidth mode from 3.4 to 8.0 GHz and a narrow bandwidth mode from 4.7 to 5.4 GHz with interport isolation better than 15 dB. Moreover, the design delivers polarization diversity with a low envelope correlation coefficient, a nearly omnidirectional radiation pattern, and a moderate gain while operating in WB and NB modes. These characteristics make the proposed antenna suitable for next-generation cognitive radio systems, where the WB antenna is used for spectrum sensing and the NB antenna for communication. View full abstract»

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  • 50. A Cognitive Radio Reconfigurable MIMO and Sensing Antenna System

    Publication Year: 2015 , Page(s): 257 - 260
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (926 KB) |  | HTML iconHTML  

    A planar, compact, single-substrate, multiband, frequency-reconfigurable multiple-input-multiple-output (MIMO) antenna system is presented. The proposed antenna elements are integrated with an ultrawideband (UWB) sensing antenna to develop a complete antenna platform for cognitive radio (CR) applications. The dual-element MIMO antenna is integrated with p-i-n and varactor diodes for frequency reconfigurability. Two modes of selection are used for the MIMO antenna system reconfigurability along with varactor tuning to sweep the frequency over a wide band especially below 1 GHz. The proposed sensing antenna is used to cover a wide range of frequency bands from 720 ~ 3440 MHz. The complete system comprising the multiband reconfigurable MIMO antennas and UWB sensing antenna for CR applications is proposed with a compact form factor. The antenna system is developed on a single substrate area of dimensions 65×120×1.56 mm3. View full abstract»

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Aims & Scope

IEEE Antennas and Wireless Propagation Letters is devoted to the rapid electronic publication of short manuscripts in the technical areas of Antennas and Wireless Propagation.

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Meet Our Editors

Editor-in-Chief
Yang Hao
School of Electronic Engineering and Computer Science
Queen Mary College, University of London