Array of Conformal Cavity-Backed Slot Antenna With Switched Beam Pattern for IoT Devices

In this paper an array of conformal antennas with switched beam patterns is presented. The array antenna consists of three $\mathbf{U}$-shaped cavity-backed slots, mounted on a cylinder. The proposed antenna has a 5.5% fractional bandwidth in the ISM band of 433 MHz. This ISM band is used in Internet of Things (IoT) devices and smart city applications. The cavity-backed structure of the proposed antenna increases the antenna gain while the conformal shape increases the half-power beamwidth. Each antenna of the proposed scheme has a gain of about 3 dB and a saddle radiation pattern with a half-power beam width (HPBW) of $\mathbf{1 2 0}$ degrees. Therefore, three examples of the proposed antenna can cover the $\mathbf{3 6 0}$-degree horizon with the beam switch network. The cylinder shape of the proposed antenna is suitable for urban traffic lights in smart traffic control systems. The proposed antenna is simulated with both time and frequency domain techniques using CST software, where results are greatly matched in both simulations.