Two-port FET oscillators with applications to active arrays

Abstract

Investigations of two-port FET oscillators and their use in active arrays for spatial power combining are reported. The two-port oscillator considered consists of a single FET oscillator with distinct input and output ports. This type of oscillator exhibits increased locking bandwidth over alternative approaches. Results are given for a prototype five-element linear array operating at 6 GHz. In this case, the entire array is synchronized by a single injection signal supplied to the first oscillator. The array exhibited a locking bandwidth of greater than 500 MHz with a 0-dBm injection signal. However, the radiation pattern had sidelobe levels below -10 dB for only 300 MHz of this range. Variation of the main lobe with frequency is shown. The main lobe direction variation is about 7% per 100 MHz of frequency change.