7.9?8.4 GHz GaAs m.e.s.f.e.t. amplifier

A 4-stage balanced GaAs m.e.s.f.e.t. amplifier has been developed for the 7.9?8.4 GHz satellite-communication frequency band. Linear gain of 26±0.5dB and 150 mW power at 1 dB compression were obtained across the design band. The small-signal gain, phase linearity, group delay and noise figure are described as a function of frequency. Large-signal gain saturation, 3rd-order intermodulation distortion, gain and phase against temperature and a.m.-to-p.m. conversion data are also presented.     

11 GHz and 12 GHz multiwatt internal matching for power GaAs f.e.t.s

Multiwatt internal-matching techniques for multichip power GaAs f.e.t.s at 11 GHz and 12 GHz bands have been developed, adopting a lumped-element input circuit and a semidistributed output circuit. The internally matched device for the 11 GHz band exhibits 4 W power output with 3.4 dB associated gain, and the 12 GHz device 3.6 W power output with 3 dB associated gain.     

GaAs power m.e.s.f.e.t.s. with a graded recess structure

A new recess structure device was developed to improve the field distrubution and therfore the performance of GaAs power m.e.s.f.e.t.s. The linear gain and the output power were improved by 1?2 dB for this structure. The highest output powers obtained are 15 W with 4 dB associated gain at 6 GHz, and 4.3 W with 3 dB associated gain at 11 GHz.     

High-efficiency Ku-band HBT MMIC power amplifier

A Ku-band monolithic HBT power amplifier was developed using a metal-organic chemical vapor deposition (MOCVD)-grown AlGaAs/GaAs heterojunction bipolar transistor (HBT) operating in common-emitter mode. At a 7.5 V collector bias, the amplifier produced 0.5 W CW output power with 5.0 dB gain and 42% power-added efficiency in the 15-16 GHz band. When operated at a single frequency (15 GHz), 0.66 W CW output power and 5.2 dB of gain were achieved with 43% PAE     

Performance of GaAs power m.e.s.f.e.t.s

Power performance results at 4 GHz are summarised for GaAs m.e.s.f.e.t.s ranging in size from 4 to 16 mm gate periphery. A double-chip 16 mm unit operated at 24 V source-drain bias produced 13.5 W with 3 dB gain and 10.7 W with 8.1 dB gain. Although lack of perfect power and gain scaling is observed, the degradation in output power of the 16 mm devices was only 1 dB compared to the smaller devices.     

X and Ku band GaAs m.e.s.f.e.t.

A GaAs Schottky-barrier f.e.t. (m.e.s.f.e.t.) with a 1 ?m gate has been built, which is suitable for X band and Ku band applications. The unilateral power gain over the X band is above 9 dB and the noise figure is only 5 dB at 10 GHz.     

X-band performance of GaAs power f.e.t.s

The results of X-band measurements on GaAs power f.e.t.s are reported. These devices are fabricated with a simple planar process. Devices with output powers of 1 W or more at 9 GHz with 4 dB gain have been fabricated from more than a dozen slices. The highest output powers observed with 4 dB gain are 1.78 W at 9 GHz and 2.5 W at 8 GHz. Devices have been operated with 46% power-added efficiency at 8 GHz.     

14-GHz band 1 watt GaAs f.e.t. amplifier

A 14.0?14.5 GHz 1 W amplifier using 0.5 ?m gate length power GaAs f.e.t.s has been developed. The amplifier, consisting of a cascade of three single-ended stages, realises 13 dB small-signal gain, 1.1 W output-power saturation and 39 dBm third-order intermodulation intercept. The circuit design and the microwave performance of the amplifier are discussed.     

Tunable X band GaAs f.e.t. amplifier

The design of a frequency-tunable X band amplifier using GaAs Schottky field-effect transistors is described. By using a broadband input matching circuit and a frequency-tunable output matching circuit, the gain of 7±0.5 dB obtained from a single-stage amplifier may be varied from 8 to 10 GHz, with corresponding terminal v.s.w.r.s, over any 600 MHz band width, better than 2:1. A single-stage amplifier gives a noise figure of 4.7 dB with a gain of 5.8 dB, and a 2-stage amplifier a 6.0 dB noise figure with 12.5 dB power gain.     

Development of highly dense four-stage flat-gain 1-W 6-18-GHz MMICpower amplifier chip

A state-of-the-art dual-channel four-stage MMIC power chip operating over C-X-Ku bands has been produced. The chip, which is only 4.35 mm×5.1 mm, operates over 6-17 GHz with very small gain ripple. At 25°C each one of its channels provides 29.5±0.5 dBm at 2-dB compression (2 dBc) from a small-signal gain of 19.5±1.5 dB. The drain bias is 7 V. and the power added efficiency is 11-14%. At 85°C, power and gain decrease by 0.5-1 and 3.5-4 dB, respectively. The design was iterated once to produce an all-monolithic amplifier chip that operates over the full 6-18-GHz frequency band and provides more than 1 W at 18 GHz. The architecture and size were maintained in the iterated design. The excellent power and gain ripple performances of the C-X-Ku chip extended to 18 GHz with a small-signal gain reduction of 0.5-1 dB. The chip is designed for use with inputs and outputs coupled externally for additional 2-2.5 dB of power. Excellent performance over 6-18 GHz was achieved using Lange couplers on 10-mil alumina     

Ku- and K-band internally matched high-power GaAs f.e.t. amplifiers

Internal-matching techniques, using lumped-element capacitors fabricated on high dielectric ceramics, have been developed for high power GaAs f.e.t.s in Ku- and K-bands. The developed internally matched high-power f.e.t. amplifier modules have exhibited 1.9 W power output with 4 dB associated gain at 14 GHz and 1.25 W power output with 3 dB associated gain at 18 GHz.     

K-band f.e.t. amplifiers

Single-stage f.e.t. amplifiers operating in K-band have been constructed using the Varian VSX 9305 0.5 ?m-gate GaAs f.e.t. An amplifier gain of 9±1 dB was obtained over the frequency band 18.5?20.5 GHz and gain of 8±1 dB was observed from 23.0 to 26.0 GHz. An amplifier noise figure of 5.6 dB was measured at 24 GHz.     

基于GaAs PHEMT工艺的60~90GHz功率放大器MMIC

研制了一款60~90 GHz功率放大器单片微波集成电路(MMIC),该MMIC采用平衡式放大结构,在较宽的频带内获得了平坦的增益、较高的输出功率及良好的输入输出驻波比(VSWR)。采用GaAs赝配高电子迁移率晶体管(PHEMT)标准工艺进行了流片,在片测试结果表明,在栅极电压为-0.3 V、漏极电压为+3 V、频率为60~90 GHz时,功率放大器MMIC的小信号增益大于13 dB,在71~76 GHz和81~86 GHz典型应用频段,功率放大器的小信号增益均大于15 dB。载体测试结果表明,栅极电压为-0.3 V、漏极电压为+3 V、频率为60~90 GHz时,该功率放大器MMIC饱和输出功率大于17.5 dBm,在71~76 GHz和81~86 GHz典型应用频段,其饱和输出功率可达到20 dBm。该功率放大器MMIC尺寸为5.25 mm×2.10 mm。     

L 波段宽带低温低噪声放大器的设计与测量*

高电子迁移率晶体管(HEMT)的小信号等效电路低温模型是研制致冷低噪声放大器(LNA)与研究晶 体管微波特性的基础。该文通过测量HEMT 器件在低温环境下直流参数与散射参数(S 参数),构建了包含噪声参 量的小信号等效电路,并据此设计了一款覆盖L 波段的宽带低温低噪声放大器(LNA),工作频率1 ~2GHz,相对带宽 达到66. 7%。在常温下放大器功率增益大于28dB,噪声温度小于39K;当环境温度制冷至11K 时,噪声温度为1. 9 ~3. 1K,输入输出端口的回波损耗S11 和S22 均优于-10dB,1dB 压缩点输出功率为9. 2dBm,功耗仅为54mW。     

Dual-gate m.e.s.f.e.t. self-oscillating X-band mixers

GaAs dual-gate m.e.s.f.e.t.s have been successfully used as self-oscillating down-convertors in X-band. A single device replaces the preamplifier, mixer and local oscillator. The best conversion gain achieved by mixing from 10 GHz down to 1 GHz was 12 dB. The input (gate 1) to output (drain) port isolation amounted to 16 dB. Slug-tuner and `disc?-resonator circuits were tested and showed comparable gain and noise performance. Best d.s.b. noise figures of 5.5 dB could be realised at an i.f. of 1 GHz with an associated conversion gain of 4 dB.     

17-GHz 50-60 mW power amplifiers in 0.13-/spl mu/m standard CMOS

Two versions of power amplifiers with different output matching approaches for the 17-GHz band were realized in 0.13-/spl mu/m standard digital CMOS technology with 1.5-V supply voltage. The power amplifier with an external matching network delivers 17.8-dBm saturated output power with 15.6% power added efficiency (PAE). The small-signal gain is 11.5 dB. The fully integrated power amplifier delivers 17.1-dBm saturated output power with 9.3% PAE. The small-signal gain is 14.5 dB. No external radio frequency components are required.     

级联型单级分布式宽带单片功率放大器

报道了一个采用级联型单级分布式结构的宽带单片功率放大器的设计方法和研制结果。文中通过拓扑比较和人工传输线理论研究,分析出该功放设计的难点,并基于仿真实验,给出解决方案。最终研制的两级单片功放在6～18GHz频率范围内线性增益13.5dB,平坦度±1dB,输入输出驻波比均小于2。全频带上,饱和输出功率为300～450mW,功率附加效率大于15%。该宽带单片功率放大器在100mm GaAs MMIC工艺线上采用0.25μm功率pHEMT标准工艺制作,芯片尺寸为2.7mm×1.25mm×0.08mm。     

A 4?8 GHz dual gate m.e.s.f.e.t. amplifier

A two-stage dual-gate f.e.t. amplifier with small signal gain of 20 ± 0.75 dB, covering an octave bandwidth (4?8 GHz) and having a dynamic gain control range in excess of 60 dB is reported. The gain frequency response, input and output v.s.w.r. are described as a function of second-gate voltage. The performance of the dual-gate f.e.t. amplifier as a fast r.f. switch is also presented.     

Broadband lumped-element X band GaAs f.e.t. amplifier

The design of a 2-stage broadband X band amplifier using GaAs Schottky field-effect transistors is described. The performance of the intrinsic device and the amplifier are summarised. The amplifier gives 9.5±1 dB gain over the frequency range 6.5?12 GHz. The v.s.w.r. at the input and the output does not exceed 2.5:1. Practical wideband matching networks are described that minimise overall amplifier noise figure and maintain a constant gain over the design bandwidth, while including the effects of parasitics, loss and discontinuity capacitances.     

SiGe MMIC power amplifier with on-chip lineariser for X-band applications

An X-band linear power amplifier with an on-chip lineariser is developed using a 0.25 mum SiGe HBT BiCMOS process. The proposed on-chip lineariser improves the 1 dB compression to as much as 3.4 dB with no additional DC power consumption. Under a 3.3 V DC power supply, the single-stage cascode amplifier shows a measured small-signal gain of 12.2 dB and output PI dB of 20.8 dBm, with power added efficiency of 27.4% at the operating frequency range 8.5-10.5 GHz.