Compact Substrate Integrated Waveguide Filtering Antennas: A Review

In recent years, with the rapid development of integrated circuits, the filtering antenna (FA) circuit of the substrate integrated waveguide (SIW) has attracted widespread attention in wireless communications. Numerous structures have been proposed to improve the performance of SIW FA. Hence, this paper presents the development and miniaturization trend of the SIW FA, and briefly introduces the structure and historical development of the SIW FA. In terms of the mode, multi-mode cavities and incomplete mode cavities are constructed. Multi-layer structures, special structures and the slow-wave technology are constructed in physical structure. Several methods and design examples of the SIW FA miniaturization are introduced from these two aspects. Based on the combination of the filter and antenna, the FA remains the advantages of the SIW structure, mainly including small size, low insertion loss, high quality-factors, and easy integration in planar radio frequency components. Therefore, it can further reduce the circuit, allowing SIW FAs to be applied in many aspects such as the 5G (5th generation mobile communication technology) and wireless local area network communications.