Broadbeam microstrip patch antenna using higher order modes

The aim of this contribution is to assess the potential of using various microstrip radiating elements excited with different modes to achieve wide pattern beamwidths. The proposed antenna is made in classic microstrip technology and consists of a circular disk and a ring. The two radiating elements are excited for the TM10 and TM31 modes, respectively. Only the disk is fed, and the ring is connected to the disk through a microstrip line. The proposed antenna is matched at the 2.4GHz industrial, scientific and medical band (ISM) and exhibits a bandwidth of 120MHz. The combination of the two radiating elements achieves a 3dB beamwidth of 160 degrees. The maximum gain is 5.7dBi.