A high-power W-band quasi-optical frequency tripler

A monolithic W-band quasi-optical array consisting of 196 heterostructure barrier varactors mounted in a waveguide has produced 684 mW of CW output power with a peak conversion efficiency of 11.3% at 93 GHz. The compact 32 mm/sup 2/ array was fabricated using two-barrier twin-mesa varactors with InGaAs/InAlAs/AlAs barriers on a lattice-matched InP substrate. Device measurements demonstrate low series resistance and high cutoff frequency. Simulations show even greater output power and efficiency can be achieved by increasing the device density in the array.