Gain Enhancement of LTCC Microstrip Patch Antenna by Suppressing Surface Waves

This chapter introduces the technology to suppress the surface wave losses caused by the thick and high‐permittivity dielectric substrate in mmW antennas. First, the mechanism of generation of surface wave losses is discussed. Then the method to suppress the surface waves is addressed with an example of patch antenna. After that, the planar and vialess antenna array operating at 60 GHz is exemplified for gain enhancement by suppressing the surface wave losses. The method to suppress the surface wave is to cut open air cavities around their radiating patches. The antenna arrays with the open air cavities achieve a gain enhancement of 1–2 dB compared with the conventional antenna array without any open air cavity across the impedance bandwidth of about 7 GHz for dB at the 60 GHz band.