Large Frequency Ratio Antennas Based on Dual-Function Periodic Slotted Patch and its Quasi-Complementary Structure for Vehicular 5G Communications

Abstract

Dual-function periodic slotted patch and its quasi-complementary structure in designing large frequency ratio antennas for vehicular 5G communications are presented in this paper. Firstly, a circular patch with periodic circular slots is employed as a partially reflecting surface (PRS) antenna in the millimeter-wave band. Simultaneously, the circular slotted patch is operated in the microwave band as a patch antenna, achieving dual functions. It is flexible to design the two antenna parts due to their polarization orthogonality. In the next place, with similar working principles, its quasi-complementary structure that contains periodic connected circular patches is also utilized for the large frequency ratio antenna design. As the proof of concept, two large frequency ratio antennas working in the 3.5-GHz and 28-GHz bands with a frequency ratio of 8 for 5G applications were designed. Finally, for verification, a periodic slotted patch antenna was fabricated and measured. Good agreement between the measured and simulated results is found. Measured -10-dB impedance bandwidths of 6.25% (3.41–3.63 GHz) and 20.57% (24.21–29.76 GHz), and measured peak antenna gains of 8.14 dBi and 14.04 dBi are obtained at the lower and upper bands, respectively. The antennas can be integrated solutions for vehicular-platform 5G microwave and millimeter-wave wireless communications.