Miniature circularly polarized antenna for SAW sensor measurements

摘要

A novel miniature antenna for a wireless pressure measurement system based on a passive Surface-Acoustic-Wave (SAW) sensor is presented in this paper. The SAW sensor used for this application works at 434MHz in the Industrial-Scientific-Medical (ISM) band. The miniature antenna (λ/12×A/17×λ/63) [6×4×1.2cm~3] consists of a Planar Inverted F Antenna with a spiral slot. The antenna presents a radiation efficiency of 50%, a bandwidth of 1.75MHz (0.4%) and a left hand circular polarization (LHCP). The SAW sensor as well as the antenna design and the association of both elements are exposed.