RF-MEMS based microwave 5-bit Phase Shifters for Phased Array Antenna Systems

This work presents the latest progress on the CONFIRM “reCONFIrable circuits by Rf Mems” project. Previous papers [1,2] have been published in recent years showing different phase shifter design typologies for the K/Ku band. This paper presents the design, fabrication and measurements of three K-band 5-bit MEMS phase shifters for phased array antennas, based on the same architecture but for different frequency bands, namely 20.7GHz, 30.5GHz and 35GHz. The devices are intended to be used in phased array antennas for SOTM (Satellite On The Move) Terminals and ESA (Electronically Scanned Antenna) seekers, in both transmitting and receiving channels [3]. They have been designed in microstrip technology using RFMEMS cantilever switches and manufactured on 200 μm thick high resistivity silicon substrate by using the wellestablished FBK MEMS process [5]. The measured results show very high performance for all devices, with RL better than 14dB and IL better than 2dB (average value) and excellent agreement with full-wave predicted results.