Sensitivity Of GaAs Impatt Diodes To Variations In Design Parameters

Abstract

INTRODUCTION Large signal computer simulations of GaAs IMPATT diodes are in good agreement with experimental results1y2. IMPATT simulations, therefore, are useful in comparing different diode designs. The IMPATT diodes can be designed to obtain the highest dc to RF conversion efficiency or maximum RF power at a given frequency or a specific frequency band. This study presents the results of a design investigation conducted on 30 GHz GaRs IMPATT diodes. The purpose of the investigation was to determine the effect that variations in design parameters have upon the operation of these diodes. The device designs considered in this study consist of a single drift flat profile, a single drift ‘hi-lo’ profile, a double drift flat profile, and a double drift hybrid profile. The hybrid profile consists of a flat profile p region and a ‘lo-hi-lo’ profile n region. The device doping profiles considered in this study are shown in Figure 1 and the corresponding physical parameters are listed in Table 1. The device simulation used in this study is a device-physics based numerical simulation of the large signal operation of IMPATT diodes2. The model requires as input data device geometry, doping densities, material transport and breakdown data, bias conditions and RF signal information. It returns data such as RF power density, conversion efficiency and harmonic information.