A Frequency-Adjustable Waveguide Filter Utilizing an E-Plane Apertured Metal Diaphragm at the D-band

A D-band filter is designed utilizing an E-plane apertured metal diaphragm (AMD) in this paper. The AMD is integrated into the filter design to facilitate fabrication. To achieve adjustable frequency, a quantitative analysis of the diaphragm parameters—specifically, width, spacing length, and aperture height—was conducted within a center frequency (CF) range of 140 GHz ± 5 GHz. A physical prototype filter was designed, fabricated, and tested, exhibiting a return loss better than 13.71 dB and an insertion loss better than 2.31dB at the CF of 141.5 GHz, with a 3 dB fractional bandwidth of 6.71%. The experimental results agree well with the simulations, indicating the potential for applications in dynamic and complex communication systems.