A Millimeter-Wave Wideband Antenna Module With Switchable Fan-Beam Radiation for Wide Coverage of 5G IoT Applications

Millimeter wave (mm-wave) antenna modules with switchable beam radiation provide a potential solution for enabling flexible wireless links and high data rate in Internet of Things (IoT) networks. Aiming to simultaneously fulfill a wide coverage and follow the cost-effective principle of IoT devices, a novel mm-wave wideband antenna module with switchable fan-beam radiation is proposed based on an air-filled planar Cassegrain beam-former. A comprehensive design procedure combing the theoretical calculation and differential evolution (DE) algorithm is first introduced to construct the beam-former with wide-angle scanning capability. The desirable aperture-shared switchable fan-beam radiation with high crossover is then obtained with the aid of a proposed two-feed-per-beam (2FPB) scheme based on a low-loss integrated switch network. A prototype of the antenna in the Ka-band is fabricated by simultaneously adopting the metallic 3-D printing and printed circuit board (PCB) technology. Excellent operating characteristics, including a wide bandwidth of more than 32%, twenty stable fan-shaped radiation beams scanning over a wide angular range of ±45° in the H-plane, a high beam crossover of about −3 dB, a gain of up to 19.6 dBi, and a radiation efficiency of greater than 80% are demonstrated experimentally. With the ability to fulfill the radio coverage within a wide conical area, the presented antenna module would be an attractive candidate for the fifth generation (5G) IoT applications.