Pattern Reconfigurable Antenna Using Circular Grooved SIW for 5G Millimeter-Wave Communications

This article presents a novel design of a 360° azimuthal plane pattern reconfigurable antenna (PRA) based on a substrate integrated waveguide (SIW) technique for 5G NR (n258) millimeter-wave (mmWave) applications. The proposed antenna consists of a compact and planar structure, exhibits wider bandwidth, better beam-shaping capability and smaller beam scanning resolution (while covering the whole azimuth plane) than contemporary designs. The design includes 20 PIN diodes for 360° pattern reconfiguration. These were simulated using the impedances given from the PIN diode’s datasheet. In the measurements, static conductive patches were used for ON states PIN diodes. The main challenge in the design of the planar CSIW at mmWave frequency bands is maintaining impedance matching when different combinations of PIN diodes are activated. Novel optimized grooves in the SIW geometry and parasitic elements created from the 2D high-impedance surfaces (HISs) have significantly improved the performance of the proposed antenna. The antenna operates from 23.5 to 27.5 GHz (covering the n258 band) having a peak gain of 11.2 dBi at 26.5 GHz and >8.5 dBi over the whole bandwidth. Moreover, it has the capability to generate dual beams from 23.3 to 26 GHz making it a promising low-cost beamforming candidate for future wireless communication systems.