A Patch Antenna With Omnidirectional and Excellent Radiation Suppression in Stop-Bands

A patch antenna with omnidirectional and excellent radiation suppression in stop-bands is proposed for 5G/6G wireless communication applications. The proposed antenna with a 0.086λ₀ profile consists of a slotted radiation patch, a stepped-impedance feedline, a slotted ground plane and four shorting pins. Having U-shaped folded slots in the radiation patch and four pins shorting the radiation patch to the ground, two resonant modes with similar performance are obtained by splitting the original resonant mode. A“Ω”-shaped and a straight slot are etched in the ground plane, the electromagnetic coupling between them helps to produce an omnidirectional radiation null at the lower band edge, and two signal transmission paths formed by them work together to enhance radiation performance. Stubs loaded to the feedline can excite an omnidirectional radiation null at the upper band edge and help to achieve a 19.54% bandwidth by exciting the third resonant mode. With the two omnidirectional radiation nulls, roll-off rates are respectively up to 216 and 76 dB/GHz at lower and upper band edges, and the radiation suppression levels are over 22.4 dB and 19.3 dB for the lower and upper stop-bands, respectively. A prototype antenna was fabricated and measured. The simulated and measured results are in a good agreement.