INTEGRATED BACK-TO-BACK BARRIER-N-N-WAVE-GUIDE BLOCK( VARACTOR DIODE TRIPLER USING A SPLIT)

The back-to-back barrier-N-N+ (bbBNN) varactor is a nonlinear device b eing developed for frequency multiplier applications above 100 GHz. It s symmetrical C-V characteristic, low series resistance, freedom from external bias and suitability to planarization make it an ideal choice for high frequency, low power, odd harmonic generation. In this paper , the performance of a 220-GHz waveguide tripler using, for the first time, a planar GaAs bbBNN device integrated on a quartz microstrip cir cuit is presented, A new split-waveguide block design has been employe d to provide the proper embedding impedances to the device at the inpu t and third harmonic output frequencies, A flange-to-flange tripling e fficiency of 7% has been obtained at 220 GHz with an output power in e xcess of 700 mu W. This is believed to be the highest conversion effic iency yet reported for a tripler with an integrated device at this fre quency, Theoretical calculations indicate that substantial improvement is possible with modest changes to the device and circuit parameters.