Isolation enhancement of rectangular dielectric resonator antennas using wideband double slit complementary split ring resonators

摘要

A wideband epsilon-negative structure is employed as one-layer and two-layer isolators to reduce mutual coupling in multiple-input multiple-output systems composed of two E-coupled rectangular dielectric resonator antennas. The proposed unit cell with -15 dB bandwidth for S-21 extending from 1970 to 3317 MHz, is a double slit complementary split ring resonator etched on the ground plane of a stripline. Each layer is composed of a 2 x 3 array of the suggested unit cell. Reduction in isolation of more than 11 dB for the one-layer case and higher than 20 dB for the two-layer case are measured within the frequency range of 2.604 to 2.64 GHz which includes WiMAX. The highest isolation level of 36 dB is realized at 2.868 GHz. The impedance matching, gain, radiation efficiency, and envelope correlation are improved compared to the original case. A prototype is designed, fabricated, and tested. Simulation data and measurement results are in good agreement.