砷化镓倍频变容管的研制

倍频变容管的特性直接影响变容管倍频器的性能。文中介绍倍频变容管的设计 ,并制作出了与设计结果基本一致的器件。获得了输入 8GHz、5 0 0 m W,输出 16 GHz,最高倍频效率大于5 0 %的二倍频测试结果 ,并给出了 8mm四倍频器的使用结果     

High-efficiency W-band GaAs monolithic frequency multipliers

High efficiency monolithic frequency multipliers have been designed, fabricated, and tested in the W-band. In microwave monolithic integrated circuits (MMICs), transmission lines with various impedances are used not only to transfer the input and output signals, but also to match the impedances of active devices to those of the input and output ports, with open and/or short stubs. Thus, loss in the transmission lines is one of the major limiting factors on circuit efficiencies. This paper presents high-efficiency MMIC frequency doublers with a balanced pair of GaAs Schottky barrier planar diodes operating in the W-band. The geometries of transmission lines were optimized to reduce the loss and thus to improve the efficiency. The demonstrated efficiency of 36.1% is the highest efficiency reported for a diode-based MMIC frequency multiplier in the W-band.     

基于基片集成波导的W波段基波注入锁定谐波振荡器

研制了一种基于基片集成波导的W波段平面注入锁定谐波振荡器.为了获得大的注入功率, 注入锁定谐波振荡器采用基波端口强耦合结构, 利用谐波提取技术的频率倍频作用, 自由振荡输出频率在90.2 GHz附近.当基波注入信号在45.08 GHz附近时, 锁定带宽大于120 MHz, 输出功率大于6.5 dBm.将该平面集成的注入锁定谐波振荡器与低频参考信号同步, 能够产生稳定的W波段低相噪信号.     

基于基片集成波导的W波段基波注入锁定谐波振荡器

研制了一种基于基片集成波导的W波段平面注入锁定谐波振荡器.为了获得大的注入功率,注入锁定谐波振荡器采用基波端口强耦合结构,利用谐波提取技术的频率倍频作用,自由振荡输出频率在90.2 GHz附近.当基波注入信号在45.08 GHz附近时,锁定带宽大干120 MHz,输出功率大于6.5 dBm.将该平面集成的注入锁定谐波振荡器与低频参考信号同步,能够产生稳定的W波段低相噪信号.     

An all-solid-state broad-band frequency multiplier chain at 1500 GHz

We report the results of a high-performance all-solid-state broad-band frequency multiplier chain at 1500 GHz, which uses four cascaded planar Schottky-barrier varactor doublers. The multipliers are driven by monolithic-microwave integrated-circuit-based high electron-mobility transistor power amplifiers around 95 GHz with 100-150 mW of pump power. The design incorporates balanced doublers utilizing novel substrateless and membrane device fabrication technologies, achieving low-loss broad-band multipliers working in the terahertz range. For a drive power of approximately 100 mW in the 88-99-GHz range, the doublers achieved room-temperature peak efficiencies of approximately 30% at the 190-GHz stage, 20% at 375 GHz, 9% at 750 GHz, and 4% at the 1500-GHz stage. When the chain was cooled to 120 K, approximately 40 /spl mu/W of peak output power was measured for 100 mW of input pump power.     

SIW-Based W-Band Low Phase-Noise Injection-Locked Harmonic Oscillator

A W-band planar injection-locked harmonic oscillator (ILHO) based on substrate integrated waveguide (SIW) is implemented. This ILHO has a free-running output frequency around 94.6?GHz while the technique of harmonic extraction from diodes is used as a frequency multiplier. It has an output locking bandwidth of 300?MHz (from 94.45 to 94.75?GHz) as injecting a signal around 47.3?GHz with the fundamental injection-locked behavior, and the output power is more than 5.8 dBm. The combination of simple synchronization with a low-frequency reference signal allows the generation of stable and low phase-noise W-band signals with a fully integrated planar source.     

Broadband electronically tunable planar active radiating elementsand spatial power combiners using notch antennas

A Gunn device has been integrated with two types of active planar notch antennas. The first types uses a coplanar waveguide (CPW) resonator an a stepped-notched antenna with bias tuning to achieve a bandwidth of 275 MHz centered at 9.33 GHz with a power output of 14.2±1.5 dBm. The second type uses a CPW resonator with a varactor for frequency tuning to achieve a bandwidth of over 1.3 GHz centered at 9.6 GHz with a power output of 14.5±0.8 dBm. This is equivalent to over 14% electronic tuning bandwidth. Both configurations exhibit a very clean and stable output signal. A theoretical circuit model was developed to facilitate the design. The model agrees well with experimental results. Injection-locking experiments on the second configuration show a locking gain of 30 dB with a locking bandwidth of 30 MHz at 10.2 GHz. Power combining experiments of two-varactor-tuned CPW active notch antenna elements in a broadside configuration have achieved well over 70% combining efficiency throughout the wide tuning range. The circuits have advantages of small size, low cost, and excellent performance     

Monolithic integrated circuits incorporating InP-based heterostructure barrier varactors

Fully integrated monolithic circuits incorporating InP-based heterostructure barrier varactor (HBV) frequency multipliers have been fabricated via epitaxial liftoff and transfer-substrate techniques onto a quartz substrate. We have obtained a maximum output power of 6 mW at 288 GHz: corresponding to an overall efficiency of 6%. In addition, we have observed a 45-GHz, 3-dB bandwidth centered around 300 GHz for a constant input power of 70 mW.     

Si-micromachined coplanar waveguides for use in high-frequencycircuits

This paper describes the development and characterization of a new class of Si-micromachined lines and circuit components for operation between 2-110 GHz. In these lines, which are a finite-ground coplanar-waveguide (FGC) type, Si micromachining is used to remove the dielectric material from the aperture regions in an effort to reduce dispersion and minimize propagation loss. Measured results have shown a considerable loss reduction to levels that compare favorably with those of membrane lines and rectangular waveguides. Micromachined FGC lines have been used to develop V- and W-band bandpass filters. The W-band micromachined FGC filter has shown a 0.8-dB improvement in insertion loss at 94 GHz over a conventional FGC line. This approach offers an excellent alternative to the membrane technology, exhibiting very low loss, no dispersion, and mode-free operation without using membranes to support the interconnect structure     

V波段变容管三倍频器

设计制作了一个从22.8GHz到68.4GHz的封装型变容管三倍频器,这是目前报导的用封装型变容管所达到的最高频率。该倍频器在结构上实现了空闲回路独立可调,从而提高了倍频效率。当频率为22.8GHz而输入功率为47mW时,最大三次谐波输出为4.9mW,最大倍频效率为10.4％,输出频率至少在2GHz的范围内倍频效率不低于7％。     

W-band monolithic frequency doubler using vertical GaAs varactor diode with n/sup +/ buried layer

A W-band monolithic frequency doubler was designed and fabricated using a vertical GaAs varactor diode that has an n/sup +/ buried layer and uses a mesa isolation process. An output power of 30 mW was obtained from this chip at 93 GHz with a conversation efficiency of 12%. This is believed to be the first reported W-band monolithic varactor diode frequency doubler.<>     

A W-band source module using MMIC's

A W-band source module providing 4-GHz tuning bandwidth (92.5-96.5 GHz) has been developed. This module consists of three MMIC chips: a 23.5 GHz HBT VCO, a 23.5-94 GHz HEMT frequency quadrupler and a W-band three-stage HEMT output amplifier, all fabricated in TRW production lines. It exhibits a measured output power of 3 dBm at 94-95 GHz and a 3-dB tuning bandwidth greater than 3 GHz, with a phase noise of -92 dBc/Hz at 1 MHz offset. This work demonstrates a new and efficient way to implement high performance W-band source. Its wide tuning bandwidth with good phase noise performance, as well as design simplicity, makes this approach attractive for many W-band system applications     

A frequency doubler for 200 GHz with a planar Schottky varactor

A frequency doubler for 200 GHz utilising a planar surface channel Schottky varactor was designed, constructed and tested. The doubler employes novel split-waveguide mount design with two sliding backshorts at both input and output waveguides. The theoretical maximum efficiency of the doubler is 44.0 % with input power level of 32 mW and the maximum output power is 16.5 mW with input power level of 50 mW. The measured maximum efficiency of the doubler was 7.1 % and the maximum output power was 2.6 mW     

A 1.7-1.9 THz local oscillator source

We report on the design and performance of a /spl times/2/spl times/3/spl times/3 frequency multiplier chain to the 1.7-1.9 THz band. GaAs-based planar Schottky diodes are utilized in each stage. A W-band power amplifier, driven by a commercially available synthesizer, was used to pump the chain with 100 mW of input power. The peak measured output power at room temperature is 3 /spl mu/W at 1740 GHz. When cooled to 120 K, the chain provides more than 1.5 /spl mu/W from 1730 to 1875 GHz and produced a peak of 15 /spl mu/W at 1746 GHz.     

A 108-GHz InP-HBT monolithic push-push VCO with low phase noise andwide tuning bandwidth

This paper reports on what is believed to be the highest frequency bipolar voltage-controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) so far reported. The W-band VCO is based on a push-push oscillator topology, which employs InP HBT technology with peak f_T's and f_max's of 75 and 200 GHz, respectively. The W-band VCO produces a maximum oscillating frequency of 108 GHz and delivers an output power of +0.92 dBm into 50 Ω. The VCO also obtains a tuning bandwidth of 2.73 GHz or 2.6% using a monolithic varactor. A phase noise of -88 dBc/Hz and -109 dBc/Hz is achieved at 1- and 10-MHz offsets, respectively, and is believed to be the lowest phase noise reported for a monolithic W-band VCO. The push-push VCO design approach demonstrated in this work enables higher VCO frequency operation, lower noise performance, and smaller size, which is attractive for millimeter-wave frequency source applications     

A high efficiency 46 to 92 GHz all microstrip frequency doubler

Using packaged GaAs varactor diodes, a high efficiency 46 to 92 GHz frequency doubler has been developed. Microstrip circuits have been used to match the input and output impedances presented by the diode. A conversion loss of 8 to 10 dB was measured. This doubler circuit is useful for W-band (75 to 110 GHz) integrated circuit receivers and transceivers. The use of microstrip circuit can drastically reduce the fabrication cost in addition to size and weight.     

Backward-wave cancellation in distributed traveling-wave photodetectors

This paper describes the design, fabrication, and measurement of backward-wave-cancelled distributed traveling-wave photodetectors. One of the fundamental issues in traveling-wave photodetectors is the generation of backward-waves, which reduces bandwidth or, in the case of matched input termination, reduces their radio-frequency (RF) efficiencies by up to 6 dB. We report a traveling-wave photodetector with multisection coplanar strip transmission lines. The reflections at the discontinuities of the transmission line cancel the backward propagating waves exactly. The bandwidth reduction due to backward-waves is eliminated without sacrificing the RF efficiency. We have demonstrated a broadband backward-wave-cancelled traveling-wave photodetector with three discrete photodiodes. The photodetector is realized in InGaAs/InGaAsP/InP material systems and operates at 1.55 /spl mu/m. A 3-dB bandwidth of 38 GHz and a linear RF output of -1 dBm at 40 GHz have been achieved. The experimental results agree very well with the theoretical calculations.     

A D-band frequency doubler MMIC based on a 100-nm metamorphic HEMT technology

A coplanar single-ended frequency doubler based on a 100 nm metamorphic HEMT technology is presented. For an input power of 4.8 dBm, this doubler demonstrates an output power between 2.6 and -0.3 dBm over the bandwidth from 105 to 145 GHz, that is, a 3-dB bandwidth of 32% has been achieved. To the knowledge of the authors, this is the first reported multiplier based on MHEMT technology at D-band or higher frequencies.     

Metamorphic HEMT MMICs and Modules for Use in a High-Bandwidth 210 GHz Radar

In this paper, we present the development of advanced W-band and G-band millimeter-wave monolithic integrated circuits (MMICs) and modules for use in a high-resolution radar system operating at 210 GHz. A W-band frequency multiplier by six as well as a subharmonically pumped 210 GHz dual-gate field-effect transistor (FET) mixer and a 105 GHz power amplifier circuit have been successfully realized using our 0.1 mum InAlAs/InGaAs based depletion-type metamorphic high electron mobility transistor (mHEMT) technology in combination with grounded coplanar circuit topology (GCPW). Additionally, a 210 GHz low-noise amplifier MMIC was fabricated using our advanced 0.05 mum mHEMT technology. To package the circuits, a set of waveguide-to-microstrip transitions has been realized on 50 mum thick quartz substrates, covering the frequency range between 75 and 220 GHz. The presented millimeter-wave components were developed for use in a novel 210 GHz radar demonstrator COBRA-210, which delivers an instantaneous bandwidth of 8 GHz and an outstanding spatial resolution of 1.8 cm.     

A Novel Quasi-Optical Frequency Multiplier Design for Millimeter and Submillimeter Wavelengths

This paper describes a novel design for millimeter and sub-millimeter wavelength varactor frequency triplers and quadruplers. The varactor diode is coupled to the pump source via waveguide and stripline impedance matching and filtering structures. Output power at the various harmonics of the pump frequency is fed to quasi-optical filtering and tuning elements. The low-loss quasi-optical structures enable near-optimum control of the impedances seen by the varactor diode at the idler and output frequencies, resulting in efficient high-order harmonic conversion. A minimum efficiency of 4 percent with 30-mW input power has been obtained for a tripler operating between 200 and 280 GHz, with a peak efficiency of 8 percent between 250 and 280 GHz. Another tripler, designed for the 260-350-GHz band, gave a minimum conversion efficiency of 3 percent with 30-mW input power, with a peak efficiency of 5 percent at 340 GHz.