A Broadband LTCC‐Based Cavity‐Backed Patch Phased Array Antenna for Ka‐Band Applications

ABSTRACT This paper presents a 4 4 millimeter‐wave (mm‐wave) phased array antenna operating in the Ka‐band (27–34 GHz) fabricated using low‐temperature co‐fired ceramic (LTCC) technology. The proposed array employs several innovative design features to achieve superior performance. An oversized aperture, combined with a parasitic patch and an embedded air cavity, significantly enhances the gain and bandwidth. Additionally, an asymmetric stripline feed structure minimises back radiation and facilitates multi‐layer integration, enabling seamless compatibility with beamforming systems. The antenna demonstrates a measured impedance bandwidth of 27% and a realised gain of 17.5 dBi at 29 GHz, with a scanning angle of . These results establish the design as a compact, high‐efficiency, and broadband solution for mm‐wave phased array applications in 5G and beyond. Experimental validation using a 16‐channel beamformer module further highlights the practicality of the design for real‐world deployment.