Mixing behavior of a dual-patch active antenna oscillator at 1.2 GHz

Active antennas have received attention in the literature for the size, weight, and cost improvements they allow. Of interest for communications purposes are self-oscillating mixer active antennas. These systems use a single active device to perform both oscillation and mixing functions. We report the significant mixing gain of a dual-patch active antenna oscillator based on a MMIC RF amplifier and operating at 1.2 GHz. The conversion gain depends on the supply voltage of the amplifier and the IF chosen. The present setup uses only four discrete components and could be used as the front-end for a simple FM receiver.