Design of frequency and beam reconfigurable antenna based on encoded reflectors for Wi-Fi and IoT applications

A frequency and beam reconfigurable antenna based on encoded reflectors for Wi-Fi and IoT applications is proposed in this paper. By modifying the traditional Alford antenna, extending the transmission line, adding radiation arms, and loading PIN diodes, the frequency reconfigurable function can be realized. Then, the three-layer reflectors are loaded around the antenna. The pattern reconfigurable function of the antenna can be achieved by encoding the operating states of the PIN diodes on the reflectors. The antenna is fed from the bottom via a coaxial transmission line, and the dimension of the antenna is 0.99λ0 × 0.99λ0. The simulated and measured results show that the working frequencies of the antenna can be switched between 1.65, 2, and 2.4 GHz with bandwidths of 2.4%, 4.4%, and 1.2%, gains of 3, 4.5, and 2 dBi, and efficiencies of 48.8%, 75.0%, and 49.6% in directional mode, respectively. The antenna works in omnidirectional radiation mode with a scanning accuracy of 10°, bandwidths of 6.6%, 4.9%, and 0.8%, gains of 0.3, 0.52, and −2.8 dBi, and efficiencies of 73.1%, 74.1%, and 51.9% at 1.65, 2, and 2.4 GHz, respectively, when the PIN diodes are tuned in off states. The antenna proposed in this paper offers several advantages, including a wider frequency band, a broader angular range, and higher precision compared to other frequency and pattern reconfigurable antennas. The antenna can be utilized for Wi-Fi and IoT communication, thereby reducing the number of antennas, enhancing communication quality and accuracy, and improving device integration.