Innovative Integration of High-Performance Floating Patch Antennas in Empty Substrate Integrated Waveguides

Substrate Integrated Circuits (SICs) represent a significant advancement in microwave communication systems due to their high efficiency, performance, and integration capabilities. Empty Substrate-Integrated Waveguides (ESIWs) are a type of SIC that offers benefits such as cost-effectiveness while maintaining high performance. This paper presents the design and implementation of the first floating patch antenna integrated into an ESIW, fed by a metallic rod. The proposed antenna is designed to operate in the X-band (8–12 GHz), with a resonance peak at 10 GHz. The patch antenna is square, which provides interesting radiation characteristics. It is excited by a metallic rod that connects the patch to the ESIW line, resulting in excellent performance in terms of measured radiation efficiency (over 90%) and −10 dB impedance bandwidth (approximately 20%). The prototype demonstrates minimal differences between the simulated and manufactured versions. These results highlight the potential of ESIW-fed floating patch antennas for advanced satellite communication systems. This will enable the integration of complete communication systems within ESIWs and facilitate the straightforward development of 2D element arrays.