Via-Guided Microstrip Patch Antenna Design With a Short Effective Wavelength Based on Miniaturized Radiating Resonators

A miniaturized patch antenna design method is proposed using a via-guided transmission line structure. Based on microstrip patch antenna models of a half-wavelength resonator and a substrate cavity, the via-guided patch antenna is designed using analytical equivalent circuits and electromagnetic field analysis. It is shown that the via-guided transmission line reduces the effective wavelength due to the slow-wave effect induced by coupling capacitance from the equivalent circuit model, which depends on via spacing and the distance to the patch. The proposed microstrip patch antenna is designed and implemented for comparison with a conventional patch. The experimental results show good agreement with theoretical design results and demonstrate an effective size reduction of 22.3%.