Low-noise parametric amplifiers tunable over one full octave

Various possible ways of tuning low noise coolable parametric amplifiers through a full octave without adjusting the pump frequency are analyzed. Based upon this analysis, a novel and simple method is proposed and practically verified. In agreement with the theory, noise temperatures between 100/spl deg/K (at 4 GHz) and 240/spl deg/K (at 8 GHz) were achieved in a balance C-band amplifier.