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Microwave and Wireless Components Letters, IEEE

Issue 4 • Date April 2005

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Displaying Results 1 - 25 of 41
  • Table of contents

    Publication Year: 2005 , Page(s): c1 - c4
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    Freely Available from IEEE
  • IEEE Microwave and Wireless Components Letters publication information

    Publication Year: 2005 , Page(s): c2
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  • A low-power Ku-band downconverter in InGaP-GaAs HBT technology

    Publication Year: 2005 , Page(s): 193 - 195
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    We have developed a low-voltage, low-power Ku-band microwave monolithic integrated circuit (MMIC) downconverter using InGaP-GaAs heterojunction bipolar transistor technology. It consists of a preamplifier, a double-balanced mixer, and an L-band wideband intermediate-frequency (IF) amplifier. The downconverter achieves a conversion gain of 31 dB, with a gain flatness within ± 1 dB, and an output-referred 1-dB compression power (P1dB,OUT) of +2.5dBm. This downconverter dissipates 33mA from a 3-V supply. We believe that the operating voltage and power consumption are lower than those of previously published Ku-band MMIC downconverters. View full abstract»

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  • Investigation on the resonance observed in the embedding-impedance response of an 850-GHz waveguide HEB mixer

    Publication Year: 2005 , Page(s): 196 - 198
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    A resonance is observed while simulating the embedding-impedance response of an 850-GHz waveguide hot-electron-bolometer (HEB) mixer. At the resonance frequency strong electric field is found distributed in the dc-grounded branch of the mixer's radio frequency (RF) choke filter. In fact, the phase response of the input reflection coefficient of the dc-grounded branch demonstrates the same resonance. Furthermore, the resonance frequency shifts with the change of the dc-ground position. A 254-times scale model of the dc-grounded branch of the mixer's RF choke filter is fabricated and measured. Experimental results are found in good agreement with the simulation results. View full abstract»

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  • A terahertz focal plane array using HEB superconducting mixers and MMIC IF amplifiers

    Publication Year: 2005 , Page(s): 199 - 201
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB) |  | HTML iconHTML  

    We present a focal plane array (FPA) designed for operation at terahertz frequencies. The FPA is based on NbN phonon-cooled hot electron bolometer mixers directly coupled to wide-band microwave monolithic integrated circuit IF amplifiers. The array incorporates all the required dc-bias and IF circuitry in a compact split-block design. We present new experimental results describing the optical coupling efficiency to the array, as well as receiver noise temperature measurements. The measurements were performed at 1.6 THz, showing good agreement with theoretical predictions. This is the first low-noise heterodyne focal plane array to be reported for any frequency above 1 THz. View full abstract»

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  • Piezoelectrically actuated RF MEMS DC contact switches with low voltage operation

    Publication Year: 2005 , Page(s): 202 - 204
    Cited by:  Papers (29)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (416 KB) |  | HTML iconHTML  

    In this paper, fully integrated radio frequency (RF) microelectromechanical system (MEMS) switches with piezoelectric actuation have been proposed, designed, fabricated, and characterized. At a very low operation voltage of 2.5V, reliable and reproducible operation of the fabricated switch was obtained. The proposed RF MEMS switch is comprised of a piezoelectric cantilever actuator with a floated contact electrode and isolated CPW transmission line suspended above the silicon substrate. The measured insertion loss and isolation of the fabricated piezoelectric switch are -0.22 dB and -42dB at a frequency of 2GHz, respectively. View full abstract»

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  • A 20-50 GHz RF MEMS single-stub impedance tuner

    Publication Year: 2005 , Page(s): 205 - 207
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB) |  | HTML iconHTML  

    A novel radio-frequency (RF) microelectromechanical system (MEMS) single-stub impedance tuner has been developed. The design is based on combining the loaded line technique with the single-stub topology to obtain wide impedance coverage with high |ΓMAX|. The tuner consist of ten switched MEMS capacitors producing 1024(210) different impedances. The design has been optimized for noise parameter and load-pull measurements of active devices and shows excellent measured impedance coverage over the 20-50 GHz frequency range. View full abstract»

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  • A W-band InAs/AlSb low-noise/low-power amplifier

    Publication Year: 2005 , Page(s): 208 - 210
    Cited by:  Papers (31)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (367 KB) |  | HTML iconHTML  

    The first W-band antimonide based compound semiconductor low-noise amplifier has been demonstrated. The compact 1.4-mm2 three-stage co-planar waveguide amplifier with 0.1-μm InAs/AlSb high electron mobility transistor devices is fabricated on a 100-μm GaAs substrate. Minimum noise-figure of 5.4dB with an associated gain of 11.1 dB is demonstrated at a total chip dissipation of 1.8 mW at 94 GHz. Biased for higher gain, 16/spl plusmn/1 dB is measured over a 77-103 GHz frequency band. View full abstract»

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  • A 2.5-GHz InGaP/GaAs differential cross-coupled self-oscillating mixer (SOM) IC

    Publication Year: 2005 , Page(s): 211 - 213
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    This letter presents a monolithic differential cross-coupled self-oscillating mixer (SOM). The SOM chip is fabricated using an InGaP/GaAs heterojunction bipolar transistor (HBT) foundry process and operates at 2.5 GHz. The chip provides voltage controlled oscillator (VCO) operation, up- and down-conversion mixing, and injection locking functionalities. The voltage down-conversion gain and the power up-conversion gain of up to 15 and 11.5 dB, respectively, are measured for the circuit. There is a compromise between obtaining a high conversion gain, and the oscillator power (-0.3 dBm for a 5-V supply) and phase noise (-84 dBc/Hz at 100 kHz). However, phase noise improvement of 32dB is observed by injection of a -30-dBm stable reference. View full abstract»

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  • A novel high-efficiency linear transmitter using injection-locked pulsed oscillator

    Publication Year: 2005 , Page(s): 214 - 216
    Cited by:  Papers (7)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    This letter presents a novel high-efficiency linear transmitter using pulse-width modulation (PWM). An envelope of radio frequency (RF) input signal is modulated by the PWM. The modulated signal is applied to the gate bias of a class F injection-locked power oscillator and switches it on and off. By filtering the pulsed oscillating output signal of the injection-locked oscillator using high-Q bandpass filter, the input signal is restored. This technique enables the transmitter to have high efficiency with good linearity. Also, there is little distortion near saturation point of an active device. The measured results show efficiency of 54.6% and very good linearity in PCS band at 26.4-dBm output power. View full abstract»

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  • Phase noise measurement of free-running microwave oscillators at 5.8 GHz using 1/3-subharmonic injection locking

    Publication Year: 2005 , Page(s): 217 - 219
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB) |  | HTML iconHTML  

    An innovative method using subharmonic injection locking technique for the phase noise measurement of free-running microwave oscillators is presented. To reduce the system cost, a two-tier injection locking approach is used and an effective 1/3-subharmonic injection is established. Measurement on a 1.8-V 5.85-GHz voltage controlled oscillator demonstrates that the measurement system is promising. View full abstract»

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  • A 5-6 GHz SiGe HBT monolithic active isolator for improving reverse isolation in wireless systems

    Publication Year: 2005 , Page(s): 220 - 222
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    A monolithic active isolator combining common-base and common-collector configurations of SiGe heterojunction bipolar transistors (HBT) is used to improve reverse isolation in wireless system applications. This simple active isolator results in an insertion loss of 2 dB and input IP3 of +0.7 dBm over 5-6 GHz with a 1.8-mA current flow for the core circuit of a 3-V supply. View full abstract»

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  • Effects of gate structures on the RF performance in PD SOI MOSFETs

    Publication Year: 2005 , Page(s): 223 - 225
    Cited by:  Papers (3)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    The radio-frequency (RF) performance of PD silicon-on-insulator metal oxide semiconductor field effect transistors with T-gate and H-gate structures has been investigated. Our measurement shows that H-gate devices have larger cutoff frequency and smaller minimum noise figure than T-gate devices. This improved RF performance in H-gate devices can be explained mainly by the enhancement of transconductance resulting from the gate extension induced inversion charges and the low gate resistance. We conclude that the H-gate structure is superior to the T-gate structure for the design of the low-noise amplifier (LNA). View full abstract»

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  • Photonic synthesis of broadband microwave arbitrary waveforms applicable to ultra-wideband communication

    Publication Year: 2005 , Page(s): 226 - 228
    Cited by:  Papers (90)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    We demonstrate photonic synthesis of broadband radio-frequency (RF) waveforms suitable for ultra-wide bandwidth (UWB) systems via open-loop reflection-mode dispersive Fourier transform optical pulse shaping. Using this technique, we synthesize broadband burst, monocycle and pulsed waveforms with RF bandwidths ranging from ∼1-8 GHz. Through appropriate optical waveform design, we demonstrate direct control over the shape of the RF spectrum - a capability that enables us to tailor our RF waveforms to conform to the low-power UWB spectral criteria. View full abstract»

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  • A 0.35-μm CMOS 2-GHz VCO in wafer-level package

    Publication Year: 2005 , Page(s): 229 - 231
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (309 KB) |  | HTML iconHTML  

    This letter presents a complementary metal oxide semiconductor (CMOS) voltage-controlled oscillator (VCO) with a high-Q inductor in a wafer-level package for the LC-resonator. The on-chip inductor is implemented using the redistribution metal layer of the wafer-level package (WLP), and therefore it is called a WLP inductor. Using the thick passivation and copper metallization, the WLP inductor has high quality-factor (Q-factor). A 2-nH inductor exhibits a Q-factor of 8 at 2 GHz. The center frequency of the VCO is 2.16 GHz with a tuning range of 385 MHz (18%). The minimum phase noise is measured to be -120.2 dBc/Hz at an offset frequency of 600 kHz. The dc power consumed by the VCO-core is 1.87 mW with a supply voltage of 1.7 V and a current of 1.1 mA. The output power with a 50-/spl Omega/ load is -12.5/spl plusmn/1.3 dBm throughout the whole tuning range. From the best of our knowledge, compared with recently published 2-GHz-band 0.35 μm CMOS VCOs in the literature, the VCO in this work shows the lowest power consumption and the best figure-of-merit. View full abstract»

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  • Microwave dielectric properties of DNA based polymers between 10 and 30 GHz

    Publication Year: 2005 , Page(s): 232 - 234
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    Deoxyribonucleic acid (DNA) based polymer thin-films were characterized at microwave frequencies for the first time. The dielectric properties of the film were extracted from comparison of the propagation constants of the co-planar waveguide (CPW) lines on bare MgO substrates and the DNA based films on MgO substrates. The insertion loss introduced by the DNA film is only 0.1 dB at 10 GHz and 0.5 dB at 30 GHz. The relative dielectric constant of the DNA based film averages to four at microwave frequencies, and the loss-tangent was below 0.1 up to 30 GHz. View full abstract»

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  • DC isolation and RF dissipation loss of coplanar waveguide on GaAs multi conductive Layers bombarded by H+ and Fe+ ions

    Publication Year: 2005 , Page(s): 235 - 237
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (90 KB) |  | HTML iconHTML  

    This letter explores the dc isolation and radio frequency (RF) dissipation loss of coplanar waveguide (CPW) lines of H+ and Fe+ ion bombarded GaAs multi conductive epitaxial layers. It is demonstrated that although a sheet resistivity as high as 108 Ωsq has been achieved by ion bombardment, showing excellent dc isolation, the RF dissipation loss of gold metallized CPW lines on the bombarded multi conductive epitaxial layers are higher than that on a semi-insulating GaAs substrate, especially at higher frequencies (0.5 dB/cm higher at 50 GHz). This is probably caused by deep level trappings due to the ion bombardment. View full abstract»

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  • A novel feed for a multifrequency hybrid resonator antenna

    Publication Year: 2005 , Page(s): 238 - 240
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (160 KB) |  | HTML iconHTML  

    A novel feed technique for a hybrid resonator antenna is proposed and developed. The antenna consists of microstrip-patch radiator and a pair of twin resonator slots. The proposed feed mechanism is based on a new coupling aperture technique, in which a single microstrip feed line is etched on the same side of the substrate as the radiating patches. The patches are coupled to the feed line through a twin slots located in the ground plane. By selecting suitable structure parameters for the slots and the patches, multifrequency operation is obtained. The proposed antenna structure is suitable for the development of large antenna arrays. View full abstract»

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  • Wideband simple cylindrical dielectric resonator antennas

    Publication Year: 2005 , Page(s): 241 - 243
    Cited by:  Papers (36)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (176 KB) |  | HTML iconHTML  

    Bandwidths of the coaxial fed and aperture coupled cylindrical dielectric resonator antennas (DRAs) with broadside radiation patterns are enhanced by exciting the HEM11Δ (1<Δ<2) mode at a frequency close to the HEM11δ (0<δ<1) mode. Both HEM11δ and HEM11Δ modes have similar broadside radiation patterns. Measured impedance bandwidths as much as 26.8% (S11<-10 dB) are achieved for the coaxial fed DRA and 23.7% for the aperture coupled DRA. These bandwidths are comparable to those obtained using stacked DRAs. The resonant frequency of the HEM11Δ mode can be adjusted by the radius (r) to height (h) ratio of the cylindrical DRA. A wide bandwidth is obtained when this ratio equals to 0.329. View full abstract»

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  • Novel integrated GPS/RKES/PCS antenna for vehicular application

    Publication Year: 2005 , Page(s): 244 - 246
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    This letter presents the design of a novel integrated global positioning system (GPS)/remote keyless entry system (RKES)/personal communication system (PCS) antenna for vehicular application. The GPS (1575.42 ± 1.023MHz) antenna element is a corner truncated microstrip patch providing circularly polarized broadside radiation pattern. The normal mode helical and monopole antennas are combined into one for RKES/PCS (447.7375MHz/1750-1870MHz) services. The proposed antenna satisfies all the bandwidth and gain requirements for GPS and RKES/PCS services. Good radiation characteristics for vehicular application have also been obtained. View full abstract»

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  • Piezoelectric transducer controlled multiple beam phased array using microstrip Rotman lens

    Publication Year: 2005 , Page(s): 247 - 249
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB) |  | HTML iconHTML  

    A simple and low-cost multiple beam phased array is designed using a microstrip Rotman lens and multi-line phase shifter controlled by a piezoelectric transducer (PET) at Ka-band. A microstrip Rotman lens with five beam ports and nine array ports is used as a feed for a multiple beam antenna array to generate five beams centered at the angles of 0°, ±15°, and ±30°. The lens fed nine-element patch array shows the antenna gain of 10 dBi and sidelobe suppression of 10 dB. Each beam is steered over ±8° using two PET-controlled phase shifters, and the five beams cover ±38° from the broadside. View full abstract»

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  • Application of the high-gain substrate-superstrate configuration to dielectric leaky-wave antennas

    Publication Year: 2005 , Page(s): 250 - 252
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB) |  | HTML iconHTML  

    The high-gain substrate-superstrate configuration, which was proposed to increase the gain in printed circuit antennas, is applied to dielectric leaky-wave antennas (LWAs) to improve its frequency response. Analysis of a slitted suspended dielectric rectangular waveguide is carried out using a full-wave method. It is proved that the minimum values of the leakage constant of the leaky-wave mode for the suspended configuration are related to the high-gain resonance conditions. Moreover, it is found that the suspended LWA exhibits very small beamwidth variations in a large frequency bandwidth. It is well-known that inhomogeneous filled LWAs suffer from variation of beamwidth as the angle of maximum radiation is scanned with frequency. The proposed topology can be adjusted so that a flat response of the beamwidth can be obtained in a large frequency band, while maintaining the frequency-scanning behavior of the LWA. View full abstract»

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  • Analysis of a coaxially fed monopole in a rectangular waveguide

    Publication Year: 2005 , Page(s): 253 - 255
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    The boundary-value problem of a coaxially fed monopole in a rectangular waveguide is solved. The technique of image method is applied to transform the original problem into an equivalent problem. A fast convergent series solution based on the Fourier transform and mode matching is presented. Our computation results compare favorably with other existing data. View full abstract»

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  • Synthesis of a self-equalized dual-passband filter

    Publication Year: 2005 , Page(s): 256 - 258
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB) |  | HTML iconHTML  

    This letter describes synthesis method for a self-equalized dual-passband filter. Compared to a conventional dual-passband filter, the self-equalized dual-passband filter can reduce bit-error rate (BER) in digital data communications and does not need an external equalizer for group delay equalization. To validate the synthesis method described in this letter, a 10-pole dual-passband filter which has two self-equalized five-pole elliptic-response passbands is synthesized. View full abstract»

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  • Dual-band bandpass filter using coupled resonator pairs

    Publication Year: 2005 , Page(s): 259 - 261
    Cited by:  Papers (27)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB) |  | HTML iconHTML  

    This letter proposes and fabricates a novel dual-band bandpass filter topology. The proposed topology facilitates the split resonating frequencies of coupled resonator pairs in realizing the dual-band response and introduces transmission zeros for improving the stopband attenuation. The semi-lumped prototype enables the integration of the filter in a multilayer circuit for miniaturized implementation. Finally, a design example fabricated with low temperature co-fired ceramic (LTCC) technology is presented for validating the filter configuration. View full abstract»

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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