【摘要】 本文介绍了在低温下,对GaAs MESFET（包括12GHz低噪声器件、双栅器件、功率器件及振荡用器件）所进行的性能测量与分析。在218K（-55℃）下,上述各类器件的跨导g_m相对于室温可增加5～8％,器件的C_gs可减少20～50％,器件的寄生电阻R_s和R_d可减少15～40％,R_g也存在缓慢下降的趋势。 文章还给出了低温下低噪声GaAs MESFET放大器的噪声、增益—温度曲线。在218K下,放大器的噪声相对室温可下降1dB左右,单级增益相对室温可增加1～1.5dB,即在低温表现出良好的微波性能。更多还原

【Abstract】 This paper describes the results of the measurements and analysis of the GaAs MESFET at low temperatures, which include low-noise devices, 2GHz dual-gate devices, 8GHz oscillator devices and power device. At 218K, it can be found that there is an increase of 5 - 8 percent in device’s transconductance gm, an decrease of 20-50 percent in Cgs and an decrease of 15-40 percent in Rs and Rd with respect to the room temperature. Rg also decreases slowly with decreasing temperature.The paper delineates Gt-T and NF-T curves of the GaAs FET amplifier as well. The curves show fine microwave performance at low temperature. The single stage gain of the amplifier increases 1 -1 .5dB, its noise figure decreases 1 dB with respect to room temperature.更多还原