Exploitation of RF-MEMS Switches for the Design of Broadband Modulated Scattering Technique Wireless Sensors

The use of RF microelectromechanical systems (RF-MEMS) switches for the design of broadband modulated scattering techniques (MSTs) wireless sensors has been investigated in this letter. In an MST sensor, the antenna is loaded with different resistive loads to produce a modulation in the backscattered field by means of an electronic switch. At microwave frequency bands, the RF switches are quite expensive, moreover, they are quite narrowband. The narrowband behavior of MST sensors is one of their major drawbacks. The adoption of RF-MEMS microwave switches could be a good opportunity to overcome this problem. In particular, MEMS switches are able to perform good up to 110 GHz with a reduced dimension and complexity. In this letter, an MST sensor prototype based on MEMS switches and able to work in the whole X-band from 8 to 12 GHz has been designed, fabricated, and experimentally assessed. The obtained results are quite good and they demonstrate the feasibility of such kind of sensors. In particular, the MEMS switches demonstrate that they could play a key role for the design of millimetric and submillimetric frequencies bands MST sensors, where the standard microwave switches technologies cannot operate.