Theoretical and Experimental Investigations on Differential Aperture-Coupled Rectangular Laminated Resonator Antenna

This letter studies differential aperture-coupled rectangular laminated resonator antenna (LRA) theoretically and experimentally. A theoretical model is proposed to analyze the resonance and radiation characteristics of the differential aperture-coupled rectangular LRA based on mode matching method. Analytical expressions for the resonant frequencies, Q-factor, impedance bandwidth (BW), radiation fields, directivity, radiation efficiency and gain are first derived. For verification, three prototypes of rectangular LRA with different length-to-height ratios differentially fed by a coupling slot are simulated, fabricated, and measured. Acceptable agreements among the calculated, simulated, and measured results are achieved. The proposed theoretical model provides physical insight into the operating principle of aperture-coupled LRA, which can be applied to predict the performances of rectangular LRAs and to instruct the design of rectangular LRAs.