Embedded air cavity backed microstrip antenna on an LTCC substrate

One of the major challenges for next-generation, highly integrated, wireless system-on-packages (SOPs) is to integrate the antenna into the package. Due to the inherent narrow bandwidth of planar antennas on LTCC substrates that have moderate relative permittivities in the range 5-20, techniques for improving the bandwidth have to be considered in order to meet the requirements of wideband telecommunication standards. This paper presents a study of laser-micromachined air cavities embedded into an LTCC substrate, and their application in improving the bandwidth of an aperture coupled microstrip patch antenna operating at around 10 GHz. Furthermore, the effects of the air cavity on the size, gain, and radiation efficiency of the antenna are presented and discussed.