Integration of tunable capacitors and bonded-wires for contactless RF switch and tunable filter
ABSTRACT This paper describes a contactless RF MEMS switch, composed of two surface-micromachined tunable capacitors and two bonded-wire inductors, which can achieve a power isolation ratio of 10 dB with a capacitance variation of mere 4:1 over a narrow bandwidth near 2.4 GHz. This novel approach of using inductors eases the deflection requirement for the deformable bridge for the variable capacitor, and allows piezoelectric ZnO film to be used to deflect the capacitor bridge to vary the air gap, thus yielding a contactless RF switch.
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ABSTRACT: This paper deals with a relatively new area of radio-frequency (RF) technology based on microelectro-mechanical systems (MEMS). RF MEMS provides a class of new devices and components which display superior high-frequency performance relative to conventional (usually semiconductor) devices, and which enable new system capabilities. In addition, MEMS devices are designed and fabricated by techniques similar to those of very large-scale integration, and can be manufactured by traditional batch-processing methods. In this paper, the only device addressed is the electrostatic microswitch - perhaps the paradigm RF-MEMS device. Through its superior performance characteristics, the microswitch is being developed in a number of existing circuits and systems, including radio front-ends, capacitor banks, and time-delay networks. The superior performance combined with ultra-low-power dissipation and large-scale integration should enable new system functionality as well. Two possibilities addressed here are quasi-optical beam steering and electrically reconfigurable antennasIEEE Transactions on Microwave Theory and Techniques 12/1998; · 2.23 Impact Factor
Conference Paper: MEMS devices for high isolation switching and tunable filtering[Show abstract] [Hide abstract]
ABSTRACT: This paper presents resonant capacitive microelectromechanical switches and their possible applications in tunable filtering. Single switches with a down capacitance of 2.9 pF and inductive sections of 3 to 50 pH are demonstrated, resulting in resonant frequencies from 13 to 54 GHz. Designs of resonant switches connected in parallel are also implemented with major advantages in isolation and bandwidth. Finally, tunable filters using these switches are discussedMicrowave Symposium Digest. 2000 IEEE MTT-S International; 02/2000
Conference Paper: RF MEMS tunable capacitors with large tuning ratio[Show abstract] [Hide abstract]
ABSTRACT: MEMS tunable capacitors have been fabricated in a thin-film technology for passive integration. Using a dual-gap relay-type design, continuous and reversible capacitance tuning with a tuning ratio up to 17 has been demonstrated, while requiring an actuation voltage of only 20 V. A quality factor of 150 to 500 has been measured in the frequency range of 1 to 6 GHz, making these devices very suitable as building blocks in many RF applications. These are the highest tuning ratio and quality factor reported to date for parallel-plate tunable capacitors.Micro Electro Mechanical Systems, 2004. 17th IEEE International Conference on. (MEMS); 02/2004