High-Frequency InP Gunn Oscillators: Simulation and Experiment

A self consistent ensemble Monte Carlo model for the simulation of InP Gunn devices has been developed and was presented in an earlier report [1]. The choice of the InP material parameters has been found to be critical to the validity of the model. Appropriate parameters were estimated by comparing the model predictions and experimental results. However, only experimental data around 83 GHz were available at that' time. Recently, very promising experimental results were obtained from 1 pm InP Gunn structures. Two doping profiles were chosen: a uniform doping of 2.5 x 10 16 cm' and a graded doping increasing linearly from 7.5 x 10 15 cm at the cathode to 2.0 x 1016 cm at tile anode. Diodes having the fiat doped structure gave 33 mW of RF power at 108.3 GHz while diodes with the graded structure yielded 20 mW at 120 GHz, 10 mW at 136 GHz and 8 111W at 155 GHz. Low measured Q values indicated that these results correspond to a fundamental mode of operation. Details of the experimental results will be presented in a separate paper. With this additional experimental data, a better estimation of InP material parameters is possible. A comparison of the resulting Monte Carlo model predictions and the experimental results is carried out. The potential of InP Gunn devices for power generation in the D-band (110 GHz 170 GHz) is then discussed. [1] R. Kamoua, H. Eisele, J.R. East, 0. I. Haddad, G. Munns, and M. Sherwin, "Modeling, Design, Fabrication, and Testing of InP Gunn Devices in the D-band ", Third International Symposium on Space Terahertz Technology March 24-26, 1992, Ann Arbor, MI. Fourth International Symposium on Space Terahertz Technology Page 341