A High-Gain Leaky-Wave Antenna Using Resonant Cavity Structure with Unidirectional Frequency Scanning Capability for 5G Applications

This paper presents a high-gain leaky-wave antenna based on a resonant cavity (RC) structure with the capability of unidirectional beam scanning over predefined frequencies and desired beam angles. Frequency scanning is achieved by implementing a properly-designed single-layer partially reflective surface (PRS) based on a simple ray tracing-based design procedure. In the proposed structure, two techniques are combined to make the beam scanning unidirectional. First, a metallic wall is placed at a proper distance from the radiator to suppress the antenna propagation at undesired directions. Second, a feed antenna with a tilted beam is designed as the main radiating element inside the cavity to radiate over desired beam angles. A prototype of the proposed antenna is fabricated and measured demonstrating a beam scanning from $12^{o}$ to $46^{o}$ over the frequency band from 25 to 31 GHz. Moreover, a maximum gain of 15.4 dBi is achieved at 26 GHz on the elevation plane with tilted angle of $22^{o}$ . The proposed leaky-wave antenna is suitable for various wireless applications, in particular the $5^{th}$ generation of cellular networks and small cell base station antenna (BSA) applications.