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

This paper presents a 4 (Formula presented.) 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 (Formula presented.). 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.