A dual-SPDT RF-MEMS switch on a small-sized LTCC phase shifter for Ku-band operation

Integration of low temperature co-fired ceramics (LTCC) technology and RF-MEMS is applicable for the realization of a small and cost-effective phase shifter. In this paper, a line-switched-type phase shifter with 3D waveguide structures and a novel design of RF-MEMS switch was demonstrated. The design method and fabrication process were reported with experimental results. The insertion loss and phase error of the 4-bit digital phase shifter on LTCC substrates with the size of 8 mm × 8 mm × 0.55 mm was measured to be around 0.5 dB/bit and less than 5% at 12.5 GHz, respectively. The Dual Single-Pole-Double-Throw (D-SPDT) MEMS switch showed driving voltage of 40 V, insertion loss of 0.9 dB, return loss of 12 dB and isolation of -29 dB at 12.5 GHz.

I. Introduction

Active phased array antenna (APAA) is expected to be widely used in the satellite communication for a mobile vehicle application in the near future because of the compactness and high scanning performance. Due to the improvement of the integration technique such as Monolithic Microwave Integrated Circuit (MMIC) and the Active Integrated Antenna (AIA) development of the APAA has been accelerated for the commercial use in the past years. Every APAA has a large number of phase shifters [1], where RF-MEMS switches [2] are expected to deliver superior performance in terms of low insertion loss and high isolation compared to those of semiconductor devices.