The rapid development of communication and radar technologies, including advancements in 5G, automotive radar, satellite communication, and weather radar systems, demands not just better bandwidth and speed but also power-efficient active antenna design capable of addressing thermal management challenges.

Thermal management has become progressively more important as small radio-frequency (RF) chips are incorporated into a tightly packed phased array to generate power and achieve beam-forming. These chips generate significant heat which accumulates between chips and antenna structures, leading to overheating, material deformation, and potential system failure. Traditional cooling solutions such as fans and liquid-based systems address these problems to some extent but are often bulky, expensive, and impractical for use in remote locations. As the need for high-frequency, high-power antenna systems grows, modern approaches that inherently mix electromagnetic performance with thermal efficiency have become essential.

Modern antenna design must therefore concentrate on integrated solutions that combine electromagnetic and thermal considerations in a compact and effective manner, which creates the research challenge. Adding more metal does not guarantee effective cooling; besides, it may deteriorate the electromagnetic radiation. Leveraging the material and structure around the antenna for both electromagnetic performance and efficient heat dissipation is a promising path. Passive cooling mechanisms, combined with innovations in antenna cavity design, have the potential to solve these challenges, paving the way for reliable, efficient, and scalable technology in high-frequency applications. However, the dual-functional design and function of antenna cavities has not been studied before.

This thesis aims to produce a new antenna structure that simultaneously enhances heat dissipation and improves electromagnetic performance, specifically bandwidth and gain. The proposed solution introduces a slotted metallic cavity with an air-gapped stacked patch and dual pin-fed excitation, integrating thermal and electromagnetic optimization within a single compact design. Unlike conventional approaches, which address thermal and electromagnetic performance as separate challenges, this work presents a unified solution that benefits both aspects without sacrificing efficiency or scalability. By systematically addressing the interplay between electromagnetic radiation and thermal management, the approach seeks to offer a more effective alternative to conventional antenna designs.