Half-Mode Substrate-Integrated Waveguides and Their Applications for Antenna Technology: A Review of the Possibilities for Antenna Design

Since its first introduction about a decade ago, the halfmode substrate-integrated waveguide (HMSIW) has gained enormous interest from researchers, with particular appeal in the antenna community. This is essentially due to the offered advantage of size reduction compared to a full SIW but more importantly to the intrinsic availability of an open aperture in the basic geometry. A great amount of effort has been spent on investigating this structure?s characteristics and its potential for integrated antenna designs, which can be efficient up to the millimeter-wave range. This article aims to provide a comprehensive snapshot of the literature on HMSIW antennas, including structure variations, analysis methods, and applications. A broad variety of HMSIW antennas covering a wide range of applications are systematically categorized, namely, into traveling-wave antennas, resonant cavity antennas, and HMSIW-fed antennas. Conclusively, the HMSIW is a versatile structure for numerous antenna applications.