An Air-gapped Cavity MEMS Filter for 5G Millime-ter Wave Applications

Abstract

This article presents a 5G millimeter Wave bandpass filter using air-gapped structure, which is fabricated through high-precision micro electromechanical system (MEMS) technique. The grounded and open stub lines, as well as impedance transformation stub lines, which generating four transmission poles (TPs) and two transmission zeros (TZs), are proposed to achieve the design goal. Four TPs support a 24.25-27.5-GHz passband, while two TZs provide a sharp out-of-band rejection. Step-to-step design process is given to guide the 24.25-27.5-GHz bandpass filter design. The 24.25-27.5-GHz bandpass filter is fabricated and measured, which has a minimum insertion loss of 0.9dB within the passband.