Competition Analysis of High- <i>Q</i> Overmoded Cavity for Enhancing High-Power Microwave Pulse Compression

To address the technical challenges of balancing power capacity and mode competition in conventional high-power microwave pulse compression systems, a high-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> overmoded resonant cavity is designed in this article. The full-wave analysis method is employed to investigate the mode composition and electric field distribution within the cavity. By judiciously selecting the cavity radius and length, the TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,2,9.5</sub> mode within the resonant cavity can be effectively suppressed, thereby significantly enhancing the purity of the TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,1,13</sub> resonant mode. The TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> mode with extremely low ohmic losses and a large longitudinal periodicity of up to 13 endows the cavity with a high-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> factor and high energy storage capability. A resonant cavity fabricated from aluminum and copper was tested using a vector network analyzer (VNA) and a mode converter. The test results show that the resonant frequency is 5718 MHz, the quality factor is approximately 99000, and the coupling coefficient is 15.90. There is no competitive mode within the range of ±50 MHz, which is consistent with the theoretical analysis and simulation results. This cavity research method demonstrates the potential for enhancing the power capacity and mode purity in high-power microwave pulse compression applications.