A C-Band Metamaterial Relativistic Magnetron With All-Cavity Extraction

Driven by the increasing demand for practical applications of high-power microwave (HPM) systems, a C-band relativistic magnetron (RM) with all-cavity extraction in the transmission region (TRACE-RM) based on a novel metamaterial (MTM) structure is proposed and investigated in this article. When conventional single-axial-period MTM RMs are extended to the C-band, maintaining high efficiency (>60%) poses the problem of excessive impedance (>$300~\Omega $), which requires a large high-energy pulsed power source. The introduction of a novel double-axial-period MTM structure can reduce the impedance to$145~\Omega $, representing a reduction of 59.7%. Meanwhile, enhanced compactness of the magnetic field system is achieved by introducing a single-axial-period MTM structure into the transmission region. High-frequency analysis confirms an 11.3% reduction in the outer radius compared with the traditional non-MTM TRACE-RM. Particle-in-cell (PIC) simulations demonstrate that when the voltage is 500 kV and the magnetic field is 0.215 T, this TRACE-RM generates a TEM mode output with a power of 1.07 GW and a frequency of 4.2 GHz, achieving a power conversion efficiency of 62.2%.