A MEMS-based electrostatically tunable circular microstrip patch antenna

• Published in: Journal of micromechanics and microengineering 2007-01, Vol.17 (1), p.1-8
• Main Authors: Jackson, R, Ramadoss, R
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/17/1/001

This paper reports a MEMS-based electrostatically tunable circular microstrip patch antenna. This antenna is fabricated using printed circuit processing techniques. The microstrip patch antenna is patterned on the top side of a Kapton polyimide film which is suspended above the ground plane. The resonant frequency of the antenna is tuned electrostatically by applying a dc bias voltage between the patch and the ground plane. The movable patch deflects downward toward the fixed ground plane due to electrostatic force of attraction caused by the applied dc bias voltage. This deflection decreases the air gap thereby increasing the effective permittivity of the antenna. This increase in effective permittivity results in a downward shift in the resonant frequency. The patch is inductively coupled to a coplanar waveguide (CPW) feed line via a slot in the ground plane. A 6 mm diameter circular patch antenna tunable from 16.91 GHz at 0 V to 16.64 GHz at 165 V, a tuning range of 270 MHz, is presented in this paper.