C-Shaped Open Slot Antenna Array for Millimeter-Wave Applications

In this article, we present a novel slot radiator to achieve a broadband and high-gain antenna array for millimeter-wave (mmW) applications. The slot radiator consists of two C-shaped apertures to generate a pair of folded magnetic dipole radiations. From the obtained results, this slot radiator can produce a broadside radiation and have a wide impedance bandwidth of 39.8% with a reflection coefficient less than −10 dB from 21.7 to 32.5 GHz. Based on the promising result from the antenna element, an $8 \times 8$ antenna array with a 1-to-64 full-corporate feed network is designed and constructed. The measured results prove that the proposed array achieves a wide impedance bandwidth of 37.1% from 21.3 to 31 GHz. Meanwhile, the gain of the array is from 26.4 to 28.3 dBi across the operating bandwidth, with an average radiation efficiency of 70.1%. This proposed antenna array has a wide bandwidth and a high directive gain, which is a good candidate for long-distance mmW communications and related applications.