Cavity Backed Patch-Slot Antenna for Lower Band 5G Communications

A cavity-backed patch antenna covering two 5G frequency bands under 6 GHz range is proposed. Good performance is obtained by optimizing the geometry of a rectangular slot and the embedded rectangular patch as well as the supporting cavity. The impedance matching between the antenna and the co-planar waveguide excitation feeding line is optimized to cover two 5G bands from 3.38 GHz to 4.35 GHz. The antenna gain is 5.68 dBi at the center frequency 3.95 GHz. A 1×5 linear array of this antenna element yields 12.03 dBi gain at the broadside with uniform excitation and up to 30° beam scanning angle with phased excitation. With the additional metal ground plane, the gain of a 1×15 linear array reaches 19.28 dBi. The geometrical properties of this simple antenna structure and its good radiating performance make it a great potential for 5G base station antenna arrays.