A Novel Stability Improvement Method of S-Band Magnetron Systems Based on Its Anode Current Feature

TL;DR

This paper introduces a new method to enhance the stability and reduce output ripples of S-band magnetrons by regulating anode current with an active distortion eliminator, improving phase stability for advanced applications.

Contribution

It presents a novel active distortion eliminator that suppresses anode current ripple and output noise, significantly improving magnetron stability and spectral purity.

Findings

Peak-to-peak anode current ripple reduced from 31 to 7 mA

Spectral width decreased from 246 to 87 kHz

Maximum spur noise suppression of 23 dB at 100 Hz

Abstract

Magnetrons are widely used as a high-efficiency, large-power, and low-cost microwave source. This article proposes a method to improve the magnetron output characteristics based on regulating its anode current by a novel active distortion eliminator. It takes advantage of the constant current state of MOSFETs to suppress the anode current ripple and eliminate the magnetron output ripples. An improved switch-mode power supply is applied to a 1-kW commercial S -band magnetron in the experiment. The peak-to-peak anode current ripple is reduced from 31 to 7 mA. The spectral width of the free-running magnetron is decreased from 246 to 87 kHz. In the injection locking state, the spur noise is significantly reduced with a maximum suppression strength of 23 dB at a 100-Hz offset. The peak-to-peak value of the magnetron magnitude and phase jitter are suppressed to 15% and 16% of their original values at a power injection ratio of 0.13. This method provides a novel approach for stabilizing the output phase of an injection-locked magnetron, making it promising for applications in phased arrays, wireless power transfer, particle accelerators, large-power communication, and other scenarios that require high phase stability.