A. Megej

Integrated microwave sensor for cavity-length measurement with sub-millimeter accuracy

A novel measurement procedure using microwaves is presented. The implemented sensor determines the length of a cylindrical cavity (e.g. hydraulic system) with sub-millimeter accuracy in real time. The principle of operation is based on the detection of the resonance-frequency distribution in a cavity resonator.

Characterization of heterostructure-barrier-varactors for frequency multiplication

This paper presents the fabrication and characterization of four-barrier planar heterostructure-barrier-varactors (HBVs) to be used in frequency triplers. The fabrication process and the DC and RF testing results are discussed. The measured results are evaluated by a newly developed combined genetic algorithm/harmonic balance simulator to calculate the optimum impedance and output power at 255 GHz. Different HBV structures were fabricated, and a comparison of their conversion efficiency is presented.

Characterization of heterostructure barrier varactors for 255 GHz tripling operation

Al/sub 0.7/Ga/sub 0.3/As/GaAs and In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As/InP HBV diodes with different mesa diameters have been fabricated and their DC characteristics have been measured. These characteristics are used by a combined genetic algorithm/harmonic balance simulator to calculate the optimum impedance and output power at 255 GHz. A comparison of the conversion efficiencies is presented for the two material systems.