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Microwave and Wireless Components Letters, IEEE

Issue 11 • Date Nov. 2006

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  • Table of contents

    Page(s): c1
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  • IEEE Microwave and Wireless Components Letters publication information

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  • A New Approach to Extrapolation of Electromagnetic Analysis in Both Time and Frequency Domains

    Page(s): 573 - 575
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (119 KB) |  | HTML iconHTML  

    A novel technique for simultaneously extracting electromagnetic responses in time and frequency domains is presented. The method involving simultaneous generation of early time and low frequency information employs a nonlinear optimization scheme to find the optimum natural frequency so as to achieve the best performance. Numerical examples are presented to demonstrate the validity of the proposed method View full abstract»

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  • Squeezing of Open Boundaries by Maxwell-Consistent Real Coordinate Transformation

    Page(s): 576 - 578
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (123 KB) |  | HTML iconHTML  

    To emulate open boundaries within a finite computational domain, real-function coordinate transformation consistent with generally covariant Maxwell equations is proposed. The mapping-realized with arctangent function here-has a transparent geometric meaning of pure squeezing of coordinates, does not introduce artificially lossy layers (or "lossy coordinates") to absorb outgoing radiation, nor lead to spurious non-Maxwellian fields. In finite-difference frequency-domain calculations on staggered grid, clear superiority over perfectly matched layers is demonstrated by the proposed technique, at a lower computation cost, in drastic elimination of parasitic coupling of guided modes to the boundaries of the computational window View full abstract»

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  • Higher Stability Limits for the Symplectic FDTD Method by Making Use of Chebyshev Polynomials

    Page(s): 579 - 581
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (302 KB) |  | HTML iconHTML  

    A new scheme is introduced for obtaining higher stability performance for the symplectic finite-difference time-domain (FDTD) method. Both the stability limit and the numerical dispersion of the symplectic FDTD are determined by a function zeta. It is shown that when the zeta function is a Chebyshev polynomial the stability limit is linearly proportional to the number of the exponential operators. Thus, the stability limit can be increased as much as possible at the cost of increased number of operators. For example, the stability limit of the four-exponential operator scheme is 0.989 and of the eight-exponential operator scheme it is 1.979 for fourth-order space discretization in three dimensions, which is almost three times the stability limit of previously published symplectic FDTD schemes with a similar number of operators. This study also shows that the numerical dispersion errors for this new scheme are less than those of the previously reported symplectic FDTD schemes View full abstract»

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  • An Open Wedge Cavity Based on the Negative Refraction of a Photonic Crystal

    Page(s): 582 - 584
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (409 KB) |  | HTML iconHTML  

    A wedge cavity within two metallic plates is suggested by filling half of the cavity with a photonic crystal with a negative effective index. The eigen frequencies and quality factors of the modes are studied with the finite element method. Phenomena associated with this open wedge cavity are explained physically. A potential application of this novel cavity as a gas sensor is also studied View full abstract»

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  • Dual Composite Right/Left-Handed (D-CRLH) Transmission Line Metamaterial

    Page(s): 585 - 587
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (154 KB) |  | HTML iconHTML  

    The novel concept of dual composite right/left-handed (D-CRLH) transmission line metamaterial is introduced. The D-CRLH is the "dual" of the conventional CRLH in the sense that it has a series parallel (instead of series) LC tank and a shunt series (instead of parallel) LC tank. This topological duality results in dual properties. The D-CRLH indeed exhibits its left-handed (LH) band at high frequencies and its right-handed (RH) band at low frequencies and is of stop-band nature, in opposition to the CRLH which is low-frequency-LH/high-frequency-RH and pass-band. The so-called balanced condition is still valid in the D-CRLH for broadband matching. However, phase origin is at dc and infinity instead, as at the LH-RH transition, and the gap between the RH and LH bands cannot be closed up in practical implementations. In contrast, the D-CRLH provides an unlimited LH bandwidth. This letter presents the homogeneous and LC-network transmission parameters and the fundamental dispersion/impedance properties of the D-CRLH View full abstract»

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  • Transmission Delay Line Based ID Generation Circuit for RFID Applications

    Page(s): 588 - 590
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB) |  | HTML iconHTML  

    A transmission delay line based ID generation circuit is presented for radio frequency identification (RFID) applications. The ID generation circuit has been designed using microstrip transmission lines as delay lines for its operation at ultra high frequency (UHF: 915MHz). The layout has been realized on a flexible substrate using photolithography based fabrication techniques. The circuit has been tested with an on-off-key (OOK) modulated input signal and different combinations of 4bit ID code have been generated. Obtained results confirm the concept and its use in RFID applications View full abstract»

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  • A Miniature Dielectric Loaded Monopole Antenna for 2.4/5 GHz WLAN Applications

    Page(s): 591 - 593
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (301 KB) |  | HTML iconHTML  

    A miniature dielectric loaded monopole antenna fed by coplanar waveguide (CPW) is proposed for WLAN applications in the 2.4/5-GHz bands. The dielectric material is a cylindrical block of ceramic with a 22 permittivity. The back side of the ceramic material with a simplified open-end tuning stub is also proposed. The prototype has been designed and fabricated and found to have bandwidths of 8% and 35.3% at the resonant frequencies of 2.48 and 5.60GHz, respectively, and the radiation patterns measured at resonance frequencies are very close to omnidirectional in the H-plane. The characteristics of the proposed antenna has been investigated using simulation software HFSS and experimental results. The measured and simulated results show excellent agreement View full abstract»

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  • Design of a New Tri-Band Microstrip BPF Using Combined Quarter-Wavelength SIRs

    Page(s): 594 - 596
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (174 KB) |  | HTML iconHTML  

    A new tri-band microstrip bandpass filter (BPF) is designed to produce three passbands at the commercially practical frequencies through a single piece of filter circuitry. The basic component used to build the proposed filter consists of two quarter-wavelength (lambda/4) stepped-impedance resonators (SIRs). One of the lambda/4 SIRs is designed to operate at 1.57 GHz and 5.25 GHz, and the other at 2.45 GHz. The feed positions for the two lambda/4 SIRs are carefully located to have the same distance from the via-hole ground and meanwhile to give the required external quality factors (Qe's). In such a way, the microstripline sections between the via-hole and each of the feed positions can be combined into one to simplify the filter structure, and to reduce the BPF circuit size. Performance of the newly designed tri-band BPF is verified by measured results View full abstract»

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  • Design of Wide-Band, Sharp-Rejection Bandpass Filters With Parallel-Coupled Lines

    Page(s): 597 - 599
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    An edge-coupled quarter wavelength resonator and half-wavelength open stubs are used for designing a highly selective wideband bandpass filter (BPF). A homogeneous medium is considered and the even-odd mode approach is used for filter analysis. Next, a microstrip line implementation procedure is described. The filter has sharp rejection, wide stopband, low insertion loss (IL), and fabrication simplicity. A prototype BPF having 69.5% 3-dB fractional bandwidth (FBW) is fabricated. A simple stub modification extends the upper 20-dB stopband to five times that of the filter upper cutoff frequency. Passband IL is within 1.6dB View full abstract»

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  • Low Insertion-Loss, Sharp-Rejection and Compact Microstrip Low-Pass Filters

    Page(s): 600 - 602
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (170 KB) |  | HTML iconHTML  

    Complementary split ring resonators are used to design compact, low insertion loss (IL), low pass filter with sharp cut-off. A prototype filter implementing area is 0.23 lambdagtimes0.09lambda g, lambdag being the guided wavelength at 3-dB cut-off frequency (fc) 1.887GHz. Maximum IL is within 0.5dB up to 1.717GHz and 20-dB stopband extends up to 3.4fc View full abstract»

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  • Varactor-Tuned Dual-Band Quadrature Hybrid Coupler

    Page(s): 603 - 605
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB) |  | HTML iconHTML  

    A tunable dual-band quadrature hybrid coupler for mobile GSM bands (900 and 1800MHz) is proposed and characterized. The structure is composed of four quarter-wavelength sections at a frequency located between the two operating frequencies and two pairs of open-ended stubs. Frequency tuning is achieved by modifying the electrical length of the open-ended stubs with varactor-diode capacitors. A dual-band tunability of 33% and 10% is obtained for the first and the second bands, respectively View full abstract»

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  • THz Waveguide Mixers With NbTiN HEBs on Silicon Nitride Membranes

    Page(s): 606 - 608
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB) |  | HTML iconHTML  

    We describe the design and performance of waveguide mixers at 1.4 THz and 1.9 THz based on NbTiN phonon-cooled hot electron bolometers (HEBs) fabricated on a 2-mum thick Si3N4 membrane. The membrane is bonded to a silicon frame in the mixer block using a flip chip process. Simulated RF coupling is compared with experimental results, showing good agreement. Receiver noise temperature measurements show uncorrected values of 1600 K at 1.4 THz and 2100 K at 1.9 THz, both at 1.5GHz intermediate frequency. Device cooling on the membrane seems not to be problematic. The mixers are used in receivers for the Stratospheric Observatory for Infrared Astronomy (SOFIA) [German REceiver At THz frequencies (GREAT)] and the Atacama path finder experiment (APEX) [CO, N+, deuterium observations receiver (CONDOR)] View full abstract»

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  • 5-GHz Low-Phase Noise CMOS Quadrature VCO

    Page(s): 609 - 611
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (495 KB) |  | HTML iconHTML  

    A 5-GHz low-phase noise CMOS quadrature voltage controlled oscillator (QVCO) is described. Two differential pairs (one for negative gm generation and the other one for the coupling input) of each resonator have separate biasing transistors which are switched on and off by the coupling input of each resonator. The proposed QVCO implemented in a 0.13-mum CMOS technology shows 17-dB phase noise improvement from a conventional QVCO with constant tail current sources while the two QVCOs consume the same power of 5.28mW. The phase noise of the proposed QVCO is measured to be -102dBc/Hz and -117dBc/Hz at 100KHz and 1-MHz offset, respectively View full abstract»

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  • A High Gain and Low Supply Voltage LNA for the Direct Conversion Application With 4-KV HBM ESD Protection in 90-nm RF CMOS

    Page(s): 612 - 614
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (465 KB) |  | HTML iconHTML  

    A 2.4-GHz low noise amplifier (LNA) for the direct conversion application with high power gain, low supply voltage and plusmn4 KV human body model (HBM) electrostatic discharge (ESD) protection level implemented by a 90-nm RF CMOS technology is demonstrated. At 12.9 mA of current consumption with a supply voltage of 1.0 V, the LNA delivers a power gain of 21.9 dB and the noise figure (NF) of 3.2 dB, while maintaining the input and output return losses below -11 dB and -18.3 dB, respectively. The power gain and NF are only 0.2 dB lower and 0.64 dB higher than those of LNA without ESD protection View full abstract»

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  • A High-Efficient CMOS RF Power Amplifier With Automatic Adaptive Bias Control

    Page(s): 615 - 617
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (463 KB) |  | HTML iconHTML  

    A 2.4-GHz Doherty power amplifier (PA) is developed in 0.18-mum CMOS technology. An automatic adaptive bias control circuit is integrated with the auxiliary PA to improve the overall performance of the PA. Operated at 3V, the P1 dB and associated power-added-efficiency (PAE) of the PA are 21dBm and 33%, respectively. At the output power 6-dB backoff from P1 dB, the PAE remains 21%. The limited PAE degradation at backoff power levels makes the PA suitable for the applications with high peak-to-average power ratio View full abstract»

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  • A Single Supply, High Linearity 2-W PA MMIC for WLAN Applications Using Quasi-Enhancement Mode PHEMTs

    Page(s): 618 - 620
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (778 KB) |  | HTML iconHTML  

    A fully matched, 2-W high linearity amplifier monolithic microwave integrated circuit, by using quasi-enhancement mode technology of AlGaAs/InGaAs/ GaAs pseudomorphic high electron mobility transistors, is demonstrated for wireless local area network applications. At Vgs= 0 V, Vds= 5 V, this power amplifier has achieved 14-dB small-signal gain, 33-dBm output power at 1-dB gain compression point, and 34.5-dBm saturated output power with 35% power added efficiency at 5.8 GHz. Moreover, high-linearity with 45.2-dBm third-order intercept point is also achieved View full abstract»

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  • A Fully Recurrent Neural Network-Based Model for Predicting Spectral Regrowth of 3G Handset Power Amplifiers With Memory Effects

    Page(s): 621 - 623
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (239 KB) |  | HTML iconHTML  

    Efficient and accurate behavioral models of power amplifiers (PAs) with memory effects are important for predicting the distortions generated by PAs in 3G handsets. Conventional recurrent neural network (RNN) has been applied for RF PAs, but its capability to model PAs with memory effects has not been investigated. In this letter, we propose a new fully RNN with Gamma tapped-delay lines suitable for modeling the dynamic behavior of 3G PAs with memory effects. After being trained with wideband code division multiple access (W-CDMA) (3GPP Uplink) signals, the proposed model is validated with not only W-CDMA but also high-speed downlink packet access (3GPP Uplink) signals with higher peak-to-average ratios (PARs), which demonstrates the generality of the model. The comparisons with previous RNN models show that the proposed model offers improved performance in predicting spectral regrowth by reducing errors by 1.7-4dB View full abstract»

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  • Composite Right/Left-Handed Transmission Line With Wire Bonded Interdigital Capacitor

    Page(s): 624 - 626
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (910 KB) |  | HTML iconHTML  

    An enhanced composite right/left-handed (CRLH) transmission line (TL) is presented in this letter. This TL, designed in microstrip technology, is implemented by means of a new improved interdigital capacitor (IDC), the so-called wire bonded IDC (WBIDC). The use of the WBIDC broadens the frequency band where the CRLH TL can be considered as a TL. A conventional 70-Omega CRLH TL (using IDCs) has been compared, by full-wave simulation and measurements, with its enhanced counterpart (using WBIDCs). In addition, this enhanced CRLH TL has been used to design a CRLH diplexer which presents several advantages over standard CRLH coupled lines (using IDCs). The diplexer response has been verified by means of a full-wave electromagnetic solver View full abstract»

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  • Simultaneous Dual Band Transmission Over Multimode Fiber-Fed Indoor Wireless Network

    Page(s): 627 - 629
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB) |  | HTML iconHTML  

    Performance measurements of different combinations of digital enhanced cordless telecommunications packet radio service, global system for mobile communications, universal mobile telecommunication service, and 802.11g (54 Mbps) signals in a dual band configuration transmitted over an indoor wireless network fed by a low-cost 850-nm vertical-cavity surface-emitting laser (VCSEL)-300m multimode fiber link are presented. The feasibility of such a system is demonstrated with error vector magnitude measurements which are within the required specifications View full abstract»

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  • Dispersion Characteristics of a Cylindrical Electromagnetic Band Gap Structure

    Page(s): 630 - 632
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (146 KB) |  | HTML iconHTML  

    In this letter, a new analytical expression for the dispersion equation of radially periodic structures is derived. The periodic structure is considered as a set of parallel cylindrical frequency selective surfaces, and the dispersion equation is calculated by using a transmission line model. Using this result, the dispersion proprieties of cylindrical electromagnetic bandgap structures composed of continuous or discontinuous metallic wires are presented. It is shown that the band structures of these materials can be determined by using the proposed dispersion equation. Cylindrical periodic materials have potential applications for designing directive antennas, circular high impedance surfaces, or agile antennas View full abstract»

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  • IEEE Microwave and Wireless Components Letters Information for authors

    Page(s): c3
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Aims & Scope

The IEEE Microwave and Wireless Components Letters (MWCL) publishes three page papers that focus on microwave theory, techniques and applications as they relate to components, devices, circuits, biological effects, and systems involving the generation, modulation, demodulation, control, transmission, and detection of microwave signals.

Full Aims & Scope