Harmonic power generation of IMPATT diodes

The harmonic power generation capability of IMPATT diodes is investigated theoretically and experimentally. The existing computer simulation program for IMPATT diodes, employing the drift-diffusion model, is used to investigate four different conventional double-drift IMPATT diodes operated in the active mode and three pin diodes with different lengths operated in the passive mode and three pin diodes with different lengths operated in the passive mode at a fundamental frequency of 23 GHz. For conventional IMPATT diodes, the depletion-layer modulation effect, which strongly depends on the diode doping structure, is essential for harmonic power generation. Because of the moderate dependence of the harmonic current on the terminal RF voltage, the GaAs and Si uniform diodes seem to be promising devices for harmonic power generation. The GaAs uniform diode can achieve the highest third-harmonic efficiency, of the order of 4.1 percent, while the Si uniform diode can achieve the highest third-harmonic power of the order of 1.