Frequency tuning of a spatial power combining array using strongly coupled oscillators

A spatial power combining array was developed and the frequency-tuning capability was investigated. This power combining array integrates single oscillator units, which are each composed of a Gunn diode and a microstrip patch antenna. Arrays consisting of four units and eight units were fabricated. By connecting oscillator units with chip resistors, the in-phase mode oscillation is obtained and is stable over a wide range of DC bias voltage. For both arrays, the oscillation frequency was tuned about 100 MHz when the DC bias voltage varied. The design of the array structure is presented and the experimental result is discussed.<>