Bidirectional slot antenna with LP and CP radiation capabilities intended for foliage obstacle detection

This paper presents a microstrip fed rectangular slot antenna on FR4, with bidirectional radiation pattern, that can radiate a wave with either circular polarization (CP) or linear polarization (LP). Its dual operation can become switchable with the integration of appropriate switches. The antenna operates at 2.4 GHz, and can be easily integrated with commercially available sensors using IEEE 802.15.4 protocol. The sensors network can detect the presence of foliage obstacles exploiting the communication link degradation caused by the attenuation and depolarization of the transmitted through foliage signal. The proposed antenna is used as the customized communication antenna of the sensor motes.