Simulation of Simplified Cascade Waveguide Plasma Limiter under High Power Microwave

With the continuous innovation and improvement of electronic information and systems, the transmission power in the equipment is also increasing. For the propagation of high-power microwaves, not only the transmission characteristics of high-power microwaves should be considered, but also the protection measures should be taken to prevent the damage caused by excessive pulses on the back-end equipment. In this article, the characteristics of waveguide plasma limiter are studied based on the plasma formed by low pressure microwave gas discharge, which reflects and absorbs electromagnetic waves. At the same time, in response to the potential power leakage problem of single-stage plasma limiters in protecting high-power microwaves, a protective device is proposed for the combination of plasma limiters and PIN limiters in rectangular waveguides. When the incident microwave intensity is strong, the electronic components are protected from burning by plasma. When the front-end plasma limiter fails to exert its effect and causes power leakage, the transmitted microwave energy is attenuated by the subsequent PIN diode limiter circuit, causing its strength to fall below the safety threshold. This limiter system model can be controlled and described by the electromagnetic (EM) fields, plasma physics and PIN equivalent circuit model. In the multi-physics cascaded waveguide limiter system, the spectral-element time-domain (SETD) method is used for system integration and self-consistent simulation analysis. The results show that the limiting performance of the cascaded limiter is much better than that of the single-stage plasma limiter under the action of HPM pulses. This research provides theoretical guidance for the use of plasma limiting devices to protect against high-power microwave damage.