HBV diodes for THz applications

Abstract

In this thesis a HBV tripler for an output frequency of 630 GHz is developed. The designed HBV is based on the InGaAs/InAlAs/AlAs epitaxially grown on InP material system and will be realised using a MMIC microstrip circuit inside a waveguide block. The doping and layer structure impact on the cut-off frequency is evaluated as well as the effects of self-heating when choosing an appropriate structure. The circuit design in the complex topology is carried out through full electro-magnetic field FEM simulations in HFSS complemented by harmonic balance simulation and optimisation in ADS. The finished multiplier simulations indicate an output power above 1 mW for an input power of 40 mW, and a relative halfpower bandwidth of 9 % at 630 GHz. Limiting factors are self heating, limited available input power, and fabrication tolerances for mesa size and substrate dimensions.