Cost-Effective High-Performance Air-Filled SIW Antenna Array for the Global 5G 26 GHz and 28 GHz Bands

A cost-effective, compact and high-performance antenna element for beamforming applications in all 5G New Radio bands in the [24.25-29.5] GHz spectrum is proposed. The novel antenna topology adopts a square patch, an edge-plated air-filled cavity, and an hourglass-shaped aperture-coupled feed to achieve a very high efficiency over a wide frequency band in a compact footprint ${(0.48\lambda_{0}\times0.48\lambda_{0})}$ . Its compliance with standard PCB fabrication technology, without complex multi-layer PCB stack, ensures low-cost fabrication. The antenna feedplane offers a platform for compact integration of active electronic circuitry. Two different modular 1×4 antenna arrays were realized to demonstrate its suitability for broadband multi-antenna systems. Measurements of the fabricated antenna element and the antenna array prototypes revealed a -10-dB impedance bandwidth of 7.15 GHz (26.8%) and 8.2 GHz (30.83%), resp. The stand-alone antenna features a stable peak gain of 7.4±0.6 dBi in the [24.25- 29.5] GHz band and a measured total efficiency of at least 86%. The 1±4 array features a peak gain of 10.1±0.7 dBi and enables grating-lobe-free beamsteering from -50° to 50°.