The self-injection-locked magnetron

This paper presents a new method of noise reduction in magnetron using self-injection-locking loop. The self-injection-locked magnetron divides into two cases in accordance to filter type: waveguide cavity filter and DR filter. This self-injection-locked magnetron consists of the coupler, high-Q filter (DR filter or waveguide cavity filter), circulator, and a phase-shifter without external source. Experimental results show that the self-injection-locked magnetron using waveguide cavity filter and DR filter is improved by 11.1 dB and 12.6 dB compared to the noise level of free oscillation magnetron at the 1 MHz offset frequency.