Compact patch antenna with space for integrating sensors for an RFID-sensor-node

Sensor applications for RFID systems received a lot of attention in the last years. Here a compact planar patch antenna that provides space for sensor elements and their connection network is presented. The proposed antenna is built up from a standard patch antenna, shortened by through-holes at two edges and has an opening in the patch metallization for placing sensor components. Placed on a metal surface the antenna behaves as a patch antenna, and in free space it has the radiation pattern of a dipole antenna.