Planar Substrate Integrated Waveguide Cavity-Backed Antenna

A new cavity-backed antenna compatible with planar technology is designed, manufactured, and measured. The original design consists of a slotted cavity fed by a microstrip line. This allows the implementation of the feeding line and the cavity on a single substrate, compatible with a standard printed circuit board (PCB) or low-temperature cofired ceramic (LTCC) process. The idea is to combine specific slot patterns on the cavity back face such as meandered and edge slots. An example is presented, and the measurements show minimum 10-dB return loss bandwidth of 1.32%, 8.5 dBi gain, and 21 dB front-to-back ratio. The combination of volume cavity, planar feeding, and antenna layout, leads to light weight, easy fabrication, and easy integration with planar circuits.