Differential-Fed Dual-Polarized Dielectric Patch Antenna With Gain Enhancement Based on Higher Order Modes

A differential-fed gain-enhanced dual-polarized dielectric patch antenna operating at higher order TM121 and TM321 modes is investigated in this letter. The introduction of grounded bars in a conventional square dielectric patch resonator (DPR) is a key technique in the proposed design. It not only moves the higher order TM121 mode upwards to enhance the gain of the antenna, but also enables the higher order TM321 mode to be excited and combined with TM121 mode to expand the bandwidth. Their corresponding degenerate modes in the DPR are used to generate a dual-polarized operation. By using two identical pairs of differential feeding lines to excite the proposed DPR, several advantages such as high isolation and low cross polarization can be obtained. For demonstration, an antenna prototype centered at about 4.9 GHz is implemented and measured. The simulated and measured results are given, showing a good agreement.