Substrate-integrated low-profile unidirectional antenna

In this study, a novel substrate integrated low-profile magneto-electric dipole antenna is proposed and investigated. The proposed antenna is composed of semi-circular patches as an electric dipole, vertical plated through holes which are shorted to the ground as a magnetic dipole, a modified ground, and a rectangular reflector for enhancing the gain. The antenna is fed via a -shaped probe. The entire structure is achieved by the multilayer printed circuit board technology, and it is suitable for mass production and low cost. By introducing the defected ground structure, the total thickness of the proposed antenna is decreased to 0.082(0) (where (0) is the free-space wavelength at 5.5GHz). To improve the impedance matching, two open slots are etched on the semi-circular patches. An antenna prototype was fabricated and measured. The results illustrate that the antenna obtains a broad bandwidth of 14.7% from 5.10 to 5.91GHz (voltage standing wave ratio (VSWR)2). Moreover, the stable gain and unidirectional radiation patterns with low back lobe and low cross polarisation in the E- and H-plane are obtained over the operating frequency band. It is demonstrated that the antenna satisfies the requirements of 5G wireless local area network, worldwide interoperability for microwave access (WiMAX), and WiFi.