Enhanced scanning range of coupled oscillator arrays utilizing frequency multipliers

Scanning in arrays is conventionally achieved through phase shifters. Recent work has indicated that scanning can be achieved with significantly reduced complexity and cost using coupled-oscillator techniques. However, the scan range has been somewhat limited using this technique. This paper describes a simple method to greatly enhance the scan range using varactor frequency doublers, which has the added advantage of simplifying the fundamental mode oscillator design. Beam scanning in antenna arrays without the use of phase shifters is theoretically and experimentally verified. The array design frequency is chosen as 8 GHz, and the fundamental mode oscillators are designed for 4 GHz.