A 5 Gc/s parametric reciever for radio astronomy

This paper describes a highly sensitive radiometer which features a degenerate parametric amplifier operating near ambient temperature. Some important techniques used to assure requisite stability are discussed in detail and a significant problem, namely that of self-generated interference, is briefly examined. Observational results are presented to demonstrate the performance of the system, which has a sensitivity of
0.05\deg
K with a time constant of 10 seconds.