A Wideband High-Gain Millimeter-Wave Antenna Array with Inverted-Feed Stacked Patch Design and Single-Port Compact Corporate Feed Network

This paper presents the design, development, and experimental validation of a novel wideband and high-gain antenna array for millimeter-wave 5G applications. The proposed structure introduces an inverted-feed stacked patch antenna element that achieves both wide impedance bandwidth and a symmetric E-plane radiation pattern. A 1×2 subarray is then constructed using an inverted T-junction feed to preserve pattern symmetry in both E- and H-planes. To further enhance gain and suppress side lobes, a 12-element linear array operating at 28 GHz is designed with a non-uniform corporate feed network. Unlike conventional approaches that rely on dual-port configurations or complex feeding structures, the proposed design utilizes a compact single-port architecture, achieving amplitude tapering through control of the number of power-splitting junctions. The final array achieves a 19.7% measured fractional bandwidth (26–31.7 GHz), peak gain of 18.1 dBi, and side lobe level below −17.3 dB, all within a compact footprint of 1.15λ×8λ. Measurement results confirm strong agreement with simulations, validating the performance of the proposed antenna. The combination of wide bandwidth, low SLL, compact structure, and simplified feed network makes the design highly suitable for next-generation millimeter-wave communication systems.