灵敏度是评价一个新系统的关键指标之一。近年来,由于各种通信频段低噪声前置放大器的发展,使微波或毫米波接收机的灵敏度有了极大提高,接收机性能大为改善。目前,砷化镓半导体研究在低噪声技术方面有所突破。研制工作包括负阻参量放大器用的变容管、作低噪声放大器泵源用的固态 Gunn 振荡器以及低噪声场效应晶体管。 Sensitivity is one of the key metrics for evaluating a new system. In recent years, due to the development of low noise preamplifiers in various communication bands, the sensitivity of microwave or millimeter-wave receivers has been greatly improved, and the receiver performance has been greatly improved. At present, gallium arsenide semiconductor research breakthroughs in low-noise technology. Development work includes a varactor for a negative resistance parametric amplifier, a solid-state Gunn oscillator for a low-noise amplifier pump, and a low-noise field-effect transistor.