45-GHZ MMIC POWER COMBINING USING A CIRCUIT-FED, SPATIALLY COMBINED ARRAY

We describe the design and measurement of a hybrid-circuit, tile-appro ach subarray for use in spatial power-combined transmitters, The subar ray consists of 16 monolithic millimeter-wave integrated circuit (MMIC ) amplifiers, each feeding a circularly polarized cavity-backed micros trip antenna, The average performance across the 43.5-45.5 GHz band is as follows: EIRP 18.3 dBW, dc-RF efficiency 10.3%, effective transmit ter power 530 mW, system gain 13.2 dB, and combining efficiency of 46. 2%, The minimum axial ratio is 1.2 dB at 43.9 GHz, and the array has a 3% 3-dB axial ratio bandwidth.