Micromachined W-Band Waveguide Duplexer Design Based on MEMS Technology

This paper presents a novel high performance W-band MEMS duplexer for digital signal transceiver applications. The design of duplexer filters follows the insertion loss method with a Chebyshev polynomial to meet the desired spectral responses. The insertion loss and return loss of the optimized duplexer are -0.3dB and -18dB respectively, while the isolation between two pass bands is -55dB. A micro-fabrication process is designed based on MEMS technology. The deep reactive ion etching (DRIE) is used for high-aspect-ratio filter cavity mold structure. Micro-electroforming, plastic embossing, and electroplating techniques are used for low-cost and high-precision mass production program for the duplexer. Fabrication error tolerance is analyzed and it is reasonable to control the shift of frequency and return loss in the range of 0.05GHz and 2dB respectively with the designed fabrication process based on MEMS technology. It proves that the proposed micromachining fabrication technique is suitable for high performance W-band waveguide filter and duplexer design in terms of stability of RF performance.