A Non-Contact-Type RF MEMS Switch for 24-GHz Radar Applications

Fabrication of a Micromachined Capacitive Switch Using the CMOS-MEMS Technology

“…The pull-in voltage of the RF switch was 25 V. The RF switch had an insertion loss of 0.29 dB at 24 GHz and an isolation of 30.1 dB at 24 GHz. Comparing to Wang et al [4] and Park et al [9], the pull-in voltage (12 V) of this work is lower than that of Wang et al [4] Park et al [9]. The springs of the RF switch in this work is designed as S-shape, so the stiffness of springs reduces, leading to decrease the pull-in voltage.…”

“…The insertion loss of the switch was 0.77 dB at 6 GHz, and the isolation of the switch was 53 dB at 6 GHz. The switch has a pull-in voltage of 15 V. Park et al [9] proposed a RF MEMS capacitive shunt switch. The switch was actuated by electrostatic force.…”

“…Wang et al [4] 0.77 dB at 6 GHz 53 dB at 6 GHz 15 Angira et al [5] 0.11 dB at 25 GHz 52 dB at 10 GHz 12.75 Giffney et al [7] 0.7 dB at 14GHz 10 dB at 14GHz 22.4 Yang et al [8] 1 dB at 20 GHz 12 dB at 20 GHz 40 Park et al [9] 0.29 dB at 24 GHz 30.1 dB at 24 GHz 25 Zheng et al [10] 0.25 dB at 25. …”

“…Experiments showed that the pull-in voltage of the switch was about 40 V. The insertion loss of the switch was about 1 dB at 20 GHz, and its isolation was about 12 dB at 20 GHz. Park et al [9] made a RF MEMS switch using the sacrificial bulk micromachining process. The switch was a capacitive shunt type, which is actuated by comb-drive actuators.…”

“…The bias voltage of microelectronic devices is usually 5 or 12 V. The pull-in voltage of these RF switches [4,[6][7][8][9][10] was between 15 to 40 V, so they needed an extra power source and increased power consumption. In this work, we employ complementary metal oxide semiconductor (CMOS)-MEMS technology to fabricate a micromachined RF switch with low actuation voltage of 12 V, and its pull-in voltage is lower than that of Wang et al [4], Angira et al [5], Gao et al [6], Giffney et al [7], Yang et al [8], Park et al [9] and Zheng et al [10]. The use of commercial CMOS process to fabricate MEMS devices is called CMOS-MEMS technology [11][12][13][14].…”