Abstract: An integrated frequency quadruplet consists of a pair of balanced frequency doublers that are driven in phase quadrature using a hybrid coupler. This approach results, effectively, in a “unilateral” multiplier that presents a match to the input-driving source, irrespective of the impedance of the doubler stages. The present invention applies this architecture to implement an integrated frequency quadruplet with output frequency of 160 GHz using quasi vertical GaAs varactors fabricated on thin silicon support membranes. The quadruplet has a balanced circuit architecture that addresses degradation issues often arising from impedance mis-matches between multiplier stages. A unique quasi-vertical diode process is used to implement the quadruplet, resulting in an integrated drop-in chip module that incorporates 18 varactors, matching networks and beamleads for mounting. The chip is tailored to fit a multiplier waveguide housing resulting in high reproducibility and consistency in manufacture and performance.

Abstract: A quasi-vertical Schottky diode architecture includes a topside anode contact that connects to external circuitry through an airbridge finger, a thin mesa of semiconductor material with epilayers including a bottomside highly-doped layer, a bottomside ohmic contact directly below the anode, and a host substrate onto which the diode material is bonded by a thin adhesive layer. A method of fabricating the diode architecture includes preparation of the semiconductor wafer for processing (including initial etching to expose the highly-doped epilayer, deposition of metals and annealing to form the ohmic contact, application of the adhesive layer to the host substrate, thermal compression bonding of diode wafer and host wafer, with ohmic contact side facing host wafer to form a composite wafer, etching and formation of diode mesas to isolate devices on the host substrate, lithography and formation of topside anode contact and external circuitry on host wafer).

Abstract: An integrated frequency quadruplet consists of a pair of balanced frequency doublers that are driven in phase quadrature using a hybrid coupler. This approach results, effectively, in a “unilateral” multiplier that presents a match to the input-driving source, irrespective of the impedance of the doubler stages. The present invention applies this architecture to implement an integrated frequency quadruplet with output frequency of 160 GHz using quasi-vertical GaAs varactors fabricated on thin silicon support membranes. The quadruplet has a balanced circuit architecture that addresses degradation issues often arising from impedance mis-matches between multiplier stages. A unique quasi-vertical diode process is used to implement the quadruplet, resulting in an integrated drop-in chip module that incorporates 18 varactors, matching networks and beamleads for mounting. The chip is tailored to fit a multiplier waveguide housing resulting in high reproducibility and consistency in manufacture and performance.

Abstract: A quasi-vertical Schottky diode architecture includes a topside anode contact that connects to external circuitry through an airbridge finger, a thin mesa of semiconductor material with epilayers including a bottomside highly-doped layer, a bottomside ohmic contact directly below the anode, and a host substrate onto which the diode material is bonded by a thin adhesive layer. A method of fabricating the diode architecture includes preparation of the semiconductor wafer for processing (including initial etching to expose the highly-doped epilayer, deposition of metals and annealing to form the ohmic contact, application of the adhesive layer to the host substrate, thermal compression bonding of diode wafer and host wafer, with ohmic contact side facing host wafer to form a composite wafer, etching and formation of diode mesas to isolate devices on the host substrate, lithography and formation of topside anode contact and external circuitry on host wafer).