Wideband Dual-Mode Patch Antenna With Compact CPW Feeding Network for Pattern Diversity Application

A wideband microstrip patch antenna is proposed in this communication for pattern diversity application. Broadside and omnidirectional radiation patterns are generated by the odd and even modes of a single circular patch. A compact feeding network based on coplanar waveguide is designed to provide in-phase and out-of-phase excitations, which can excite the two modes in wide bandwidth. The size of the feeding network is only 35 × 14.5 mm
²
. A prototype of the proposed antenna is fabricated and tested. The measured overlapped bandwidth (|S
₁₁
| <; -10 dB and |S
₂₂
| <; -10 dB) achieves 775 MHz (2.165-2.94 GHz) or 31% corresponding to the center frequency. The Port isolation is below -28 dB in the entire bandwidth.