A Novel Dielectric Constant Measurement Method Based on SIW Slot Array Antenna

A new dielectric constant measurement method based on SIW (Substrate integrated waveguide) slot array traveling wave antenna is proposed in this paper. The SIW slot array antennas working at W-band using the different substrates are designed in this paper for verification. The simulation results show that when the substrate dielectric constant is 2.1, 2.2, 2.3, the main beam direction of the array will aim at -8.1°, -5°, and -2°, respectively. Thus, there is a mapping relationship between the substrate dielectric constant and the main beam direction. This method is very simple and can capture the small changes of dielectric constant of the substrate.