Broadband Low-Profile Patch Antenna With Efficiency-Optimized Coupling for 5G Mobile Terminals

This letter presents a simple, compact and fabrication-friendly wideband patch antenna enabled by an optimized coupling mechanism, specifically designed for fifth-generation (5G) mobile terminals. The proposed antenna consists of a driven patch and a parasitic patch printed on a single substrate layer, eliminating the need for an air layer or shorting vias and thereby greatly reducing structural complexity. By strategically optimizing the length and width of the parasitic patch, the amplitude–phase coupling between the driven and parasitic patches is precisely regulated. This optimization disrupts the strong anti-phase current cancellation that typically occurs in parasitic-element-assisted designs, enabling simultaneous bandwidth enhancement and efficiency preservation, effectively resolving the long-standing tradeoff between broad bandwidth and high radiation efficiency. A prototype antenna was fabricated and measured to validate the proposed method, with results showing excellent agreement with simulations. The realized antenna operates across 3.3–4.2 GHz, fully covering the 5G N77 band.