Micromachined low-loss microwave switches

The design and fabrication of a micromechanical capacitive membrane microwave switching device is described. The switching element consists of a thin metallic membrane, which has two states, actuated or unactuated, depending on the applied bias. A microwave signal is switched on and off when the membrane is switched between the two states. These switches have a switching on speed of less than 6 /spl mu/s and a switching off speed of less than 4 /spl mu/s. The switching voltage is about 50 V. The switches have a bowtie shape and showed low insertion loss of 0.14 dB at 20 GHz and 0.25 dB at 35 GHz, and isolation of 24 dB at 20 GHz and 35 dB at 35 GHz. These devices offer the potential for building a new generation of low-loss high-linearity microwave circuits for a variety of phased antenna arrays for radar and communications applications.

[1]  S. Eshelman,et al.  Characteristics of micromachined switches at microwave frequencies , 1996, 1996 IEEE MTT-S International Microwave Symposium Digest.

[2]  K. Petersen.  Micromechanical membrane switches on silicon , 1979 .

[3]  S. Senturia,et al.  Self-consistent simulation and modelling of electrostatically deformed diaphragms , 1994, Proceedings IEEE Micro Electro Mechanical Systems An Investigation of Micro Structures, Sensors, Actuators, Machines and Robotic Systems.

[4]  Xi-Qing Sun,et al.  A micro variable inductor chip using MEMS relays , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[5]  Kevin W. Kobayashi,et al.  Monolithic GaAs HBT p-i-n diode variable gain amplifiers, attenuators, and switches , 1993 .

[6]  C. Goldsmith,et al.  Micromechanical membrane switches for microwave applications , 1995, Proceedings of 1995 IEEE MTT-S International Microwave Symposium.

[7]  Peter M. Osterberg,et al.  Electrostatically actuated microelectromechanical test structures for material property measurement , 1995 .

[8]  R. H. Caverly.  Distortion in off-state arsenide MESFET switches , 1993 .

[9]  M. F. Chang,et al.  A Surface Micromachined Miniature Switch For Telecommunications Applications With Signal Frequencies From DC Up To 4 Ghz , 1995, Proceedings of the International Solid-State Sensors and Actuators Conference - TRANSDUCERS '95.

[10]  Lawrence E. Larson,et al.  Micromachined microwave actuator (MIMAC) technology-a new tuning approach for microwave integrated circuits , 1991, IEEE 1991 Microwave and Millimeter-Wave Monolithic Circuits Symposium. Digest of Papers.