Design of the Radiation-type Circularly-Polarized Programmable Metasurface Unit

This work presents a design of the radiation-type circularly-polarized programmable metasurface unit. The metasurface unit is excited by a coupled microstrip probe, and two PIN diodes are integrated on the unit radiation patch, and the two diodes are placed in an antisymmetric manner. By controlling the bias voltage of the PIN diode, the radiation beam of the antenna unit can present two different phases of 0° and 180°, corresponding to the digital code “0” and “1”. When the two diodes are in different states, the radiation beam of metasurface unit presents a phase difference of 180° in a certain range, which can realize the dynamic regulation of electromagnetic radiation characteristics.