Injection locked oscillator arrays for spectrum analysis

Injection locked oscillator arrays are described as a means of quasi-real-time spectrum analysis. Two oscillators with closely spaced frequencies at 5.1 and 5.8 GHz were designed such that single or simultaneous injection locking may occur depending on the injected frequency and power. The locking range for a -20 dBm input is greater than 150 MHz for each oscillator and at 0 dBm the oscillators share a locking range greater than 500 MHz. Isolation higher than 14 dB was measured between both oscillators under maximum injection conditions. Injection sensitivity, isolation, and phase noise characteristics are described and measured. Single or simultaneous injection locking of two neighboring oscillators is illustrated in a 0.12 mum SiGe BiCMOS process using only NMOS devices.