Millimeter-Wave Rectangular Dielectric Resonator Antenna Array with Enlarged DRA Dimensions, Wideband Capability, and High-Gain Performance

In this communication, a rectangular dielectric resonator antenna (DRA) is integrated with a backed cavity to enlarge the DRA side length by 1.8 times. The backed cavity also reduces the sensitivity of the DRA resonance to the DRA size, resulting in a relaxed fabrication tolerance. Based on the enlarged DRA design, a stacked DRA (sDRA) is proposed to improve the bandwidth from 8.7% to 15% and enhance the realized gain by an average of 1.5 dB. The proposed mechanisms are verified by fabricating a $4\times4$ sDRA array with an enlarged DRA side length of 1.8 mm ( .40 {\lambda }$ ), an improved bandwidth of 62.7-73.9 GHz (16.4%), and an enhanced measured gain of up to 17.2 dBi. The enlarged DRA dimension permits a higher DRA operating frequency without reducing the DRA size. The proposed millimeter-wave (mmW) sDRA array provides a wide bandwidth and high-gain solution for 67 GHz unlicensed band communications.