Analysis and Research on Noise Injection Calibration Method of K-band Ambient Temperature Receiver

Noise injection calibration method is widely used as a conventional amplitude calibration method in centimeter band receiver. Through the establishment of K-band ambient temperature receiver and its amplitude calibration platform, the traditional cold and hot load method is used to calibrate the receiver noise temperature and noise source temperature at indoor temperature of 20 ℃, and then the same method is used to calibrate the receiver noise temperature and noise source temperature at outdoor temperature of -7 ℃, and the indoor calibrated temperature noise source is used to further calibrate the receiver noise temperature in outdoor environment. The test results show that when the ambient temperature changes by about 27 degrees, the difference of receiver noise temperature calibration is about 50.5%, and the difference of standard noise source calibration is about 41%. Therefore, if the noise injection method is applied to the calibration of ambient temperature receiver, the receiver should be treated with constant temperature first, and the injected standard noise source can be compensated with temperature to make it more accurately applied to the secondary calibration, which is the next work of this paper.