Full-scale Nonlinear Analysis of LHL Ga As IMPATT Amplifiers

Abstract: The analysis of LHL Ga As IMPATT Diode structure has been developed on the basis of IMPATT nonlinear model. The paper presents a detailed analysis of the effect of peak value of the microwave signal and the operating conditions on the performance of GaAs IMPATT amplifiers. It is indicated that the variation of peak RF voltages gives rise to three modes of operation (conventional mode and two high-efficiency modes). During the high-efficiency modes, the induced current has one or two additional peaks at the proper phase angles in the RF cycle due to the bunching and acceleration of the avalanche-generated packet of electrons. The diode conductance and the generated RF power increase sharply during the high-efficiency operation. Important conclusions concerning the effects of the dc bias current and operating frequency on the performance of this device are drawn. The results presented here are obtained using a full-scale computer simulation program that takes fully into account all the physical effects pertinent to the IMPATT diode operation.They will help optimize the Ga As IMPATT structure and its operating conditions