Compact Substrate Integrated Waveguide Filtering Antennas: A Review

Abstract

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.INDEX TERMS Substrate integrated waveguide (SIW), filtering antenna (FA), multi-mode, incomplete mode, multi-layer, slow-wave technology.

A single‐layer substrate‐integrated waveguide filtering antenna with three independently controllable radiation nulls

“…Introduction: In recent years, integrated and miniaturized radio frequency (RF) front-end has become a research hotspot. The filter and antenna are usually connected as separate structures in wireless communication systems, but the direct connection generates problems such as poor matching and additional insertion loss [1][2][3]. A filtering antenna is proposed to accomplish better matching impedance and significantly reduce the size of the RF front-end [4].…”

“…However, numerous particular applications require lower insertion loss and higher Q of the antenna, and the substrate-integrated waveguide (SIW) is applied to design filtering antennas [5][6][7][8]. As an on-chip waveguide structure [9], SIW possesses the advantages of microstrip line and waveguide with high Q, low loss, and easy integration [1]. The radiation null is an essential indicator in filtering antennas, representing a better out-of-band rejection level.…”