Combination dielectric resonator, power combiner, and antenna

A rectangular dielectric resonator housed in a cutoff parallel-plate wavegu ide is used both as a radiating element and microwave power combiner. The r esonator is excited by using tuned electrically short monopole antennas to induce a longitudinal electric operating mode. The resonator is then used i n conjunction with free-running oscillators in order to provide, via mutual injection locking, stable in-phase power combining. Furthermore, the reson ator is arranged such that one of its faces radiates a portion of the power -combined signal. Since the resonator is housed in a cutoff waveguide, the cross-polarization radiation from the antenna is suppressed. It was found t hat, for a single element, a gain in the azimuthal plane of 5 dB could be a chieved and, for a two-element array, a gain of 7 dB was obtained with bett er than -25-dB cross polarization for each case. The oscillator power-combi ning efficiency for a single-element antenna (two oscillators) was 91%, and the spatial power-combining efficiency for a two-element antenna array, (f our oscillators) was found to be 90%, In addition, it is shown that the pre sence of the dielectric inserts in conjunction with coupled oscillator dyna mics provides moderate overall oscillator phase noise improvement.