A miniaturized half-mode substrate integrated waveguide (HMSIW) antenna is presented which resonates at a frequency of 6.78 GHz. The S-parameters and radiation patterns are investigated by full-wave simulation and the simulated results show the unidirectional radiation pattern. The proposed is single layered, compact in size, and can be easily integrated with planar PCB technology. It also takes the features of conventional cavity-backed antennas including high gain and good radiation pattern. © 2016 IEEE.