Broadband Symmetrical E-Shaped Patch Antenna With Multimode Resonance for 5G Millimeter-Wave Applications

A symmetrical E-shaped patch antenna with multimode resonance is proposed for 5G broadband millimeter-wave (mmWave) applications. A longitudinal slot is etched on the patch surface to change the original E-field distribution of the TM20 mode without affecting that of the TM10 mode. This etching also tunes the resonance frequencies of these two modes to be sufficiently close to each other. Therefore, the antenna is able to realize good impedance performance within the wide designated bandwidth. Moreover, two transverse slots are etched to suppress undesirable modes, but the slots have a small effect on the current distribution of the two designed modes. Thus, the antenna is able to realize a stable radiation pattern and low cross-polarization within the whole operating band. The proposed patch antenna is designed, fabricated, and measured around the $Ka$ -band. The fabricated prototype achieves a wide impedance bandwidth of 45.4%. The simulated total efficiency of the proposed antenna is more than 85.0%. The proposed broadband symmetrical E-shaped patch antenna has a very simple structure and great electrical performance and is a very attractive candidate for 5G mmWave applications.