Design of Polarization-Reconfigurable Pixel Antennas With Optimized PIN-Diode Implementation

In this article, a systematic approach is proposed for integrating ten polarization states in a reconfigurable pixel antenna. Different from conventional reconfigurable pixel antennas with PIN diodes between every adjacent pixel pair, the pin-diode implementations are optimized skillfully in this work to avoid redundancy. As a result, the PIN diodes are fully exploited, reducing fabrication costs and potential insertion loss. The initial configuration of the antenna involves pixel structures with N discrete ports. The multiobjective optimization is then conducted based on the framework of the N-port network and solved using nondominated sorting genetic algorithm III (NSGA-III). Decision variables include the locations of PIN diodes, their circuitry states across different polarizations, and the states of the other ports without diodes. Consequently, two CP and eight LP states are obtained on a compact platform at 2.4-GHz WLAN/BT band, with merely 12 PIN diodes. The antenna prototype with the digital controller was fabricated and measured, with the measured results agreeing well with the simulated ones. The deca-polarization-reconfigurable antenna serves as a promising candidate for intelligent communication and sensing systems. The proposed method provides a promising solution for the flexible design of reconfigurable antennas.