In the first portion of this thesis, a procedure is presented for the design of a new stable IMPATT-diode microstrip amplifier with excellent and almost independent control of center frequency and gainbandwidth product. The intermodulation distortion of the microstrip amplifier is then measured on a spectrum analyzer using a phase-locked microwave two-tone generator for the input signal. The test is performed on the microstrip amplifier first without, and then with a diode bias-current compensation technique. An improvement of 15 dB to 25 dB in the third-order intermodulation products is obtained in the band of the amplifier using the bias compensation circuit. This improvement opens the possibility for IMPATT microstrip amplifiers to be used in AM transmission systems whose modulation frequencies lie within the band of the video amplifiers employed in the bias-current compensation loop.