A 340GHz Cross-coupled Waveguide Filter Based on MEMS Process

In this paper, a waveguide bandpass filter (BPF) operating at 340 GHz based on micro-electro-mechanical systems (MEMS) process is designed. The filter uses a classic fourth-order cross-coupled structure. The negative coupling is realized by a TE $_{\mathbf{102}}$ mode. To provide convenience for connection and measurement, two vertical transitions with the same height as the filter are designed on the upper and lower sides. The simulation results show that the filter has a center frequency of 341.2 GHz with a 3 dB FBW of 19.7 GHz. The average insertion loss (IL) of the passband is 0.7 dB, and the return loss is better than 15 dB. The influences of machining tolerance caused by the MEMS process on center frequency, bandwidth, and stopband rejection are also analyzed in this paper.