A 5-17 GHz wideband reflection-type phase shifter using digitally operated capacitive MEMS switches

摘要

In this paper, a micromachined low-loss and ultra wideband reflection-type phase shifter (RTPS) is proposed. The phase shifter shows a constant phase shift from 5 to 17 GHz and consists of two cascaded reflection-type phase shifter. Low-loss reflection termination consists of digital capacitive switches, and air-gap overlay CPW couplers are used in order to employ the low-loss 3 dB coupling. The fabricated phase shifter showed the 5 discrete states, 0/spl deg/, 22.5/spl deg/, 45/spl deg/, 67.5/spl deg/, 90/spl deg/ respectively, the average insertion loss of 3.48 dB, and maximum rms phase error of /spl plusmn/ 1.80/spl deg/ for the relative phase sift from 0/spl deg/ to 90/spl deg/ over 5-17GHz.