Parallel-Plate Transmission Line and L-Plate Feeding Differentially Driven H-Slot Patch Antenna

A newly developed patch antenna, designated as the parallel-plate transmission line and L-plate feeding differentially driven H-slot patch antenna, is presented in this letter. The parallel-plate transmission line will not introduce inductance to the input impedance of a patch antenna, thus the height of the patch can be largely increased. In addition, by employing L-plate feeding and H-slot patch simultaneously, the height of the patch can reach 0.25λ
₀
. Measurements show that the impedance bandwidth can be extended to 115% (0.79-2.94 GHz) and 3-dB-gain bandwidth can be extended to 83% (0.80-1.93 GHz). The radiation pattern is stable, and the maximum gain is 9.9 dBi within the 3-dB-gain bandwidth.