SUBMILLIMETER-WAVE GENERATION AND NOISE IN INP DIODES

High-frequency (350-750 GHz) generation in submicrometer InP diodes is investigated by modified hydrodynamic and Monte Carlo particle (MCP) techniques. The noise power spectral density P-n in the diode loaded by resistor R and generation spectra P-g in a series resonant RL circuit are calculated using the MCP technique. It is shown that at the biases above the generation threshold the P-n has a peak at the frequency f(max) which corresponds to the highest generation frequency at the given R. The excess noise arises in the frequency region where the real part of diode impedance Re Z has negative values. At the bias below the generation threshold (i.e., when Re Z is positive over entire frequency range) the P-n(f) has the usual Lorenzian shape. The MCP simulation of P-g for 0.25-mu m-length diode shows the Gaussian shape of the spectra at frequencies 517 and 622 GHz. The P-g broadening at higher frequencies is the result of interaction between the self-oscillations at frequency f(max) and circuit-driven oscillations.