Since their emergence in the late 1990s, several research groups have studied RF-microelectromechanical-systems (MEMS) antennas. To achieve multiple octave tunability, emphasis was placed on reconfigurable aperture (recap) and microstrip antenna structures. The integration of RF-MEMS with the antenna was just demonstrated recently, however, thanks to the efforts of Xinglong Guo, Jianming Cui, Miao Cai, Lei Liu, Zongsheng Lai, and Peisheng Xin from East China Normal University.
The students demonstrated a miniature reconfigurable antenna that was designed and fabricated on a high-resistivity silicon substrate. The antenna can be integrated with a MEMS actuator to reconfigure the operating frequency. RFMEMS switches are used to perform switching between two different frequency bands. In the open/closed experiments, the antenna operating frequencies are 12.3 and 13.1 GHz, respectively, when the switch is on and off. The final model radiated at two widely separated frequencies with very similar radiation patterns.
This development relied on slot antennas, which do not increase antenna-element dimensions. They therefore can be used in planar phased arrays. Construction and operation are simplified, as each switch demands only a single bias line for control. The paper also introduces an on-wafer pattern measurement technique, which does not require individual antennas to be diced and separated on the wafer. The antenna development can be extended to reconfigurable linear antenna arrays or more complex antenna structures. See "Re-Configurable Kµ Dual-Band Slot Antenna Using MEMS Switches," Microwave and Optical Technology Letters, December 2006, Vol. 48, No. 12, p. 2413.