Experimental studies on a low power injection-locked continuous wave magnetron

An injection-locked magnetron was investigated at low power injection. The 1 kW magnetron has been locked over the ratio of the input power to output power of -57 dB. It is much less than the required injection power in previous experiments. The purity of spectrum was presented. The phase noise of the locked magnetron was less than -93.1 dBc/Hz at 10 kHz offset. The oscillation spectrum has FM noise due to the spurious of input reference signal and injection locking contributes to reducing the FM noise itself to some extent. The injection locking technique may be applied to power combining or large-power amplifiers based on magnetrons.