Realizing orthogonal modes in compact cavity-backed dual-polarized antenna through simple feeding structures for millimeter-wave AiP applications

This paper presents a dual-polarized cavity-backed antenna designed for mm-wave applications, featuring simple feeding structures with a high-isolation for 60 GHz compact AiP applications. The dual-polarization design relies on two separate feed ports that excite two orthogonal modes within the same resonant cavity, achieving very high port isolation of up to 40 dB over the entire band. We conducted a detail analysis of the antenna, including its working principles and parametric studies. For verification, we fabricated an antenna test kit using standard printed process on substrates and measured the kit from the back-side of a GSG probing platform. The proposed antenna demonstrates a wide impedance bandwidth, stable radiation patterns, very low cross-polarization levels, and a high radiation efficiency. The co-located cavity-backed design ensures the compactness and facilitates easy integration with ICs in a very small AiP module. These features make the proposed antenna highly suitable for 60 GHz AiP applications, such as high-data-rate wireless communication and mmW polarimetric radar systems.