2-LEVEL POWER COMBINING USING A LENS AMPLIFIER

A two-level quasi-optical power combiner is presented. The combiner co nsists of a grid oscillator which feeds a transmission amplifier at it s focal point. The focal-point feed improves power coupling efficiency over that of a plane-wave feed. A linear 7-element lens amplifier arr ay demonstrates 29 dB of isolation and a 30 degrees continuous scan an gle with less than 1 dB power variation at 9.7 GHz. A 24-element two-d imensional lens amplifier array fed by a grid oscillator demonstrates 5.7 dB gain and a 30 degrees scan angle with less than 2dB power varia tion at 10.25 GHz. When horn-fed, the 24-element lens has an isolation of 17-21 dB over a 3% bandwidth. The grid oscillator, as well as rece ive and transmit sections of the lens amplifiers, are each fabricated on single substrates, making monolithic millimeter-wave integration of each component possible.