本文从卫星地面侦察站的低噪声接收设备出发,结合我们多年来研制低温参放和常温参放等低噪声放大器以及“冷、热噪声源”的工作实践,概述了参放的噪声机理和超低噪声测试的一般原理,并着重介绍了我们所研制的“冷热噪声源”对于“冷参放”的超低噪声特性的研究情况,供从事雷达、电子对抗及遥感微波辐射计等专业的科技工作者参考。并期望从事这方面工作的同志能对我们的工作予以指教。 Based on our low noise amplifier and low noise amplifier for cold ground and thermal noise source for many years, this paper summarizes the noise mechanism and parameters Low noise test principle, and emphatically introduced our research “cold and hot noise source” on the “cold parametric” ultra low noise characteristics of the research, for engaged in radar, electronic warfare and remote sensing microwave radiometer and other professional Technical workers reference. We hope that comrades engaged in this field can give advice to our work.