GaAs and InP punchthrough diodes as oscillators in the millimetre-wave range

Microwave properties of GaAs and InP punchthrough diodes in the millimeter-wave range are investigated in this paper. By means of an exact large-signal computer simulation, taking into account the carrier velocity-field dependence, diffusion phenomena and a realistic doping profile, the influence of the negative differential mobility on oscillation performance is studied. Large negative resistances can then be obtained with well-designed n+–p–n–n+structures. At a frequency of 40 GHz, optimum output powers of 20mW and 120mW have been calculated for GaAs and InP materials, respectively. The corresponding non-linear resistances are −7Ω and −7.5 Ω. An interesting use can then be expected as a self-oscillating mixer or as Doppler radar in the millimetre-wave range.