High-Gain Cavity-Backed Slot Antenna Array based on ENZ Medium for Millimeter Waves

This work proposes a high-gain waveguide-fed cavity-backed slot antenna array based on ENZ medium for millimeter wave operation. The array’s elements comprise a metallic cavity doped by FR4 dielectric slabs surrounded by four metallic rods to achieve an ENZ medium. The array’s elements were excited by a T-junction 4:1 power divider fed by a commercial single waveguide-to-coaxial transition through a standard WR28 waveguide. Two symmetrical wing-based reflectors were also applied to the array for gain increment. The array full-wave numerical analyses results show a bandwidth of 630 MHz (26.04 26.67 GHz), a gain of 22.12 dBi, side lobe levels below 14.67 dB, and radiation efficiency of 49.88%.