Effects of transient carrier transport in millimeter-wave GaAs diodes

Effects of transient carrier transport on the performance of millimeter-wave GaAs diodes are investigated using results obtained from a Monte Carlo simulation of electron transport. Transit-time devices (such as IMPATT´s and TUNNETT´s) are discussed first. Mechanisms by which transient effects in the drifting charge pulse may enhance or degrade performance are identified and discussed. Attention is then focused on electron transport in the undepleted epitaxial material which will be present in mixer and varactor diodes and may be present in transit-time diodes. The frequency and signal-level dependence of the conductance of such material is calculated and the implications for device performance are discussed.