Performance of monolithic GaAs FET oscillators at J-band

Monolithic GaAs FET oscillators were demonstrated at J-band frequencies. Output power up to 160 mW with 23-percent efficiency at 12 GHz was achieved. With a discrete tuning varactor, a 300-µm gate-width FET monolithic oscillator was tuned from 16 to 20 GHz. The average output power was l0 mW.     

Fabrication and performance of GaAs p+n junction and Schottky barrier millimeter IMPATT's

A recently developed procedure, incorporating both preferential electrochemical etching for wafer thinning and electroplating for heat sink formation has been applied to the fabrication of Kaband (26.5-40 GHz) GaAs IMPATT's. Both epitaxially grown GaAs p⁺n junction and Cr Schottky barrier diodes have been fabricated. This procedure makes possible the batch fabrication of small area diodes (<2 times 10^{-5}cm²) over a large wafer area. The diodes have been operated both in the oscillator and stable-amplifier mode. Power, efficiency, and noise performance of the devices is reported. The p⁺n diodes, which could withstand junction temperature of over 300°C, gave the best power and efficiency. Powers as high as 680 mW with 12.4 percent efficiency at 34.8 GHz and an efficiency as high as 16 percent with 390 mW at 29.5 GHz have been achieved. The Cr Schottky diodes were unable to withstand junction temperatures in excess of 200°C and therefore produced less power despite the potentially better power handling capability. The highest power obtained from a Cr Schottky is 470 mW with 12.5 percent efficiency at 34 GHz. Comparable oscillator noise performance has been obtained with both types of diode. The best AM (DSB) double sideband NSR obtained is -135 dB in a 100 Hz window at 1.5 MHz from the carrier. An rms frequency deviation as low as 13 Hz in a 100 Hz window has been observed with a power output of 164 mW at 35.4 GHz by raising the external Q to 138. A lowest FM noise measure of 23 dB was achieved by reducing output power to 16 mW. The amplifier noise figure measured for both p⁺n and Cr Schottky diodes is 26 dB.     

基于CMOS工艺的太赫兹振荡器

在太赫兹频段,无源器件电容电感的品质因数低、电路的寄生参数以及MOS管的截止频率影响使太赫兹振荡器电路难以实现高功率输出。提出一种300 GHz可调谐振荡器,首先,采用改进的交叉耦合双推(Push-Push)振荡器结构,通过输出功率叠加的方法输出二次谐波300 GHz信号,增加了振荡器的输出功率并突破了MOS管截止频率,并通过增加栅极互连电感增加输出功率。其次,太赫兹振荡器摒弃传统片上可变电容调谐的方式,通过调节MOS管衬底电压改变MOS管的栅极寄生电容实现频率调谐,避免太赫兹频段引入低Q值电容,进一步增加了输出功率。提出的太赫兹振荡器采用台积电40 nm CMOS工艺,基波工作频率为154.5 GHz,输出二次谐波为 309.0 GHz,输出功率可达-3.0 dBm,相位噪声为-79.5 dBc/Hz@1 MHz,功耗为28.6 mW,频率调谐范围为303.5~315.4 GHz。     

Design of GaAs MESFET Oscillator Using Large-Signal S-Parameters

A design method of GaAs MESFET oscillator using large-signal S-parameters has been discussed. Together with the measurement results of the dependence of Iarge-signall S-parameters on power levels and bias conditions, computer analysis of the equivalent circuit for MESFET'S has qualitatively clarified the large signal properties of MESFET'S. On the basis of these findings, S-parameters have been designed for the MESFET oscillator over the frequency range of 6-10 GHz, which has resulted in power output of 45 mW at 10 GHz with 19-percent efficiency, and 350 mW at 6.5 GHz with 26-percent efficiency, respectively. Good agreements between predicted and obtained performances of MIC positive feedback oscillator have been ascertained, verifying the validity of the design method using large-signal S-parameters.     

A 50-GHz silicon IMPATT diode oscillator and amplifier

Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.     

2cm波段耿管电调振荡器

报道了采用部分集成方案研制的Ｋｕ波段变容管调谐耿管振荡器（ＶＣＯ）及两管功率合成器。研制的两只中心频率为１６和１７ＧＨＺ的电调振荡器，其中１６ＧＨＺ的电调带宽大于６４０ＭＨｚ，输出功率大于１１０ｍＷ，功率起伏小于０．６ｄＢ；而１７ＧＨｚ的电调带宽大于２３０ＭＨｚ，输出功率大于１１０ｍＷ，功率起伏小于０．９ｄＢ。两管功率合成器的振荡频率为１７．３ＧＨｚ，输出功率达２５０ｍＷ．     

0.2 THz二倍频器研究

基于六阳极结反向串联型GaAs平面肖特基二极管,设计并实现了0.2 THz大功率二倍频器。肖特基二极管倒装焊接在50m石英电路上。采用电磁场和电路联合设计仿真获得了二倍频器的倍频效率。当入射功率在100 mW时,输出频率在190~225 GHz带内效率大于5%。在小功率（Pin100 mW）和大功率（Pin300 mW）注入条件下,测试了倍频电路的输出功率和倍频效率。在100 mW驱动功率下采用自偏压测试,最大输出功率为14.5 mW@193 GHz,对应倍频效率为14%;在300 mW驱动功率下采用自偏压测试,在188~195 GHz,输出功率大于10 mW,最大输出功率为35 mW@192.8 GHz,对应倍频效率为11%。     

High-performance millimetre-wave suspended stripline Gunn VCO

A novel millimetre-wave integrated circuit Gunn voltagecontrolled oscillator (VCO) has been developed with high output power using suspended stripline. An output power of 100 to 150mW has been achieved at frequencies between 33 and 42 GHz. A varactor diode was mounted in alignment and in close proximity to the Gunn diode to achieve an electronic tuning range of 300 MHz     

Microstrip Varactor-Tuned Millimeter-Wave Transmitter (Letters)

A 60-GHz varactor-tuned microstrip oscillator intended for use in a millimeter-wave radio relay experiment has been designed and tested. The output power of the transmitter is 110 /spl plusmn/ 15 mW from 58.5 to 60.1 GHz. The oscillator can be frequency-shift keyed (FSK) at a rate up to 200 Mbit/s. The rms FM noise of about 400 Hz/(kHz)/sup 1/2/ meets the required system specifications.     

High performance millimetre Ge-GaAs mixer diode for low l.o. power applications

Epitaxial Ge/GaAs low-barrier-height Ti-Mo-Au Schottkybarrier diodes exhibit a noise figure of 6.5 dB at 36 GHz and at 0.75 mW of local oscillator (l.o.) power. These diodes represent significant improvement over standard GaAs-Ti diodes at low power levels.     

Microwave Varactor Tuned Transistor Oscillator Design

An analysis is made of the common base microwave transistor oscillator circuit which uses a varactor in series with the colIector to tune over octave bandwidths. Equations are derived giving the required feedback capacitances and resonating elements required for octave tuning. Normally, the collector-emitter capacitance C/sub ce/ is made approximately equal to the transistor collector capacitance C/sub c/. The emitter-base capacitance C/sub eb/ is important only at very high frequencies. It is shown that a high-Q varactor must be used and that only a limited amount of collector-base capacitance C/sub cb/ may be added if the circuit is to be resonated over an octave. The output power for such a circuit is normally about 1/5 the maximum power available from the transistor. Experimental oscillators were made from 0.5 to 1 GHz and 1 to 2 GHz which substantially verified the analysis. Using the TIXS13 transistor, an output power of 200 mW was obtained from 430 to 860 MHz tuning from -2 to -115 volts. In the 1 to 2 GHz range a TIXS13 transistor oscillator was tuned from 1.09-1.96 GHz with about 40 mW power tuning from -2 to -115 volts. By use of a lower case capacitance varactor, the 1 to 2 GHz oscillator could be made to tune over the full octave.     

Novel f.e.t. power oscillator

An X-band GaAs f.e.t. oscillator is described that uses a novel configuration, designated `reverse-channel oscillator?. This provides output powers of up to 0.94 W at 8 GHz and efficiencies as high as 37%. At a higher frequency this configuration provided approximately 300 mW output at 17.5 GHz.     

基于GaAs工艺的36GHz压控振荡器

利用法国OMMIC公司的0.2μm GaAs PHEMT工艺,设计实现了一个36GHz压控振荡器电路.该电路采用完全差分的调谐振荡器结构,通过引进容性源极耦合差动电流放大器和调谐负载电路,提高了电路的性能.测试表明:该压控振荡器中心频率为36GHz,调谐范围约为800MHz,在偏离中心频率10MHz处的单边带相位噪声为-98.83dBc/Hz.芯片面积为0.5mm×1mm,采用-5V单电源供电,核心单元功耗约为200mW.     

A W-band Frequency Source with Low Spurs and Low Phase Noise

A W-band millimeter wave frequency source is developed by frequency multiplier chain and injection locking. The referenced crystal oscillator (CO) signal 120 MHz is multiplied 400 times to output 48 GHz signal. Then, it is used as a referenced source of fundamental-wave injection-locked harmonic Gunn oscillator with output power more than 10 mW at 96 GHz and spurious output less than ?65 dBc. The measured phase noise is ?97 and ?105 dBc/Hz at 10 kHz and 200 kHz offset, respectively. At last, the influence of the flicker noise, provided by the frequency multipliers and amplifiers, is analyzed.     

Submillimeter-wave InP Gunn devices

Recent advances in design and technology significantly improved the performance of low-noise InP Gunn devices in oscillators first at D-band (110-170 GHz) and then at W-band (75-110 GHz) frequencies. More importantly, they next resulted in orders of magnitude higher RF output power levels above D-band and operation in a second-harmonic mode up to at least 325 GHz. Examples of the state-of-the-art performance are continuous-wave RF power levels of more than 30 mW at 193 GHz, more than 3.5 mW at 300 GHz, and more than 2 mW at 315 GHz. The dc power requirements of these oscillators compare favorably with those of RF sources driving frequency multiplier chains to reach the same output RF power levels and frequencies. Two different types of doping profiles, a graded profile and one with a doping notch at the cathode, are prime candidates for operation at submillimeter-wave frequencies. Generation of significant RF power levels from InP Gunn devices with these optimized doping profiles is predicted up to at least 500 GHz and the performance predictions for the two different types of doping profiles are compared.     

0.22 THz宽带混频电路研究

基于中国电子科技集团公司第十三研究所的反向并联肖特基二极管,采用电磁场和电路软件联合仿真,完成了0.22 THz分谐波混频电路设计。在固定中频输出频率10 MHz的条件下测试了混频电路的变频损耗,在175~235 GHz共60 GHz带宽内双边带变频损耗小于15 dB,在196 GHz处最佳变频损耗为8.5 dB。测试结果与仿真结果趋势吻合良好。基于冷热负载,测试了分谐波混频电路的噪声温度,当本振功率为5.7 mW时,在216 GHz处双边带噪声温度为1 200 K。     

CW oscillation characteristics of GaAs Schottky-barrier gate field-effect transistors

The CW oscillation characteristics of GaAs Schottky-barrier gate FET's have been examined at 10 GHz. The maximum output power of 41.2 mW and the maximum efficiency of 15.6 percent have been obtained for the GaAs FET with a gate length of 1.5 µm and an electrode width of 300 µm. The experimental results have shown that the GaAs FET possesses promising features for an oscillator application as well as an amplifier application.     

Fully integrated W-band microstrip oscillator

A fully integrated microstrip oscillator is described. The active element is an InP transferred-electron device operating in its fundamental mode of oscillation. For measurement purposes, the oscillator structure is mounted in a test assembly and fitted with a waveguide to microstrip transition. Output powers of 16 mW have been observed at the waveguide output port at frequencies in the range 80 GHz to 83 GHz. Transition and circuit losses are approximately 3 dB indicating a device output power of 32 mW.     

Heterodyne radiometry measurements of the 557 GHz H2O rotational line

A high-resolution heterodyne radiometer that utilizes a crossed-guide harmonic mixer pumped by a 300 GHz carcinotron as a local oscillator has been developed for submillimeter wavelengths. Previous investigations of the radiation transfer properties of spectral lines in supersonic gas flow have been extended to longer wavelengths using the tunability of this system. With less than 2 mW of fundamental local oscillator power, traces of the 557 GHz ortho-H2O rotational transition (1_{10} leftarrow 1_{01}), Doppler-broadened to only a few MHz, were observed in absorption against a continuum background.