微波行波量子放大器是利用顺磁晶体中的活性粒子的受激辐射而产生放大的一种极低噪声的微波前置放大器。它是在五十年代未到六十年代初期发展起来的。微波量子放大器的主要优点是有极低的噪声,高的功率增盖和高的增益稳定性。在厘米波段,它的噪声可做到8～10K,在毫米波段可做到20～30K。这样低的噪声在目前是其它放大器所无法做到的。由 Microwave traveling wave quantum amplifier is an extremely low noise microwave preamplifier that utilizes the stimulated emission of active particles in a paramagnetic crystal to produce amplification. It was not developed in the 1950s and early 1960s. The main advantages of microwave quantum amplifiers are very low noise, high power capping and high gain stability. In the centimeter band, its noise can be done 8 ~ 10K, in the millimeter band can be done 20 ~ 30K. This low noise is currently not possible with other amplifiers. by