Design of the Radiation-type Circularly-polarized Programmable Metasurface Array

This article proposes the conceptual design of a radiation type circularly-polarized programmable metasurface array. The metasurface array consists of periodic circularly-polarized metasurface unit, which is fed through an unequal series and parallel hybrid feeding network. The metasurface unit is excited by a coupled microstrip probe, and two PIN diodes are integrated on the unit radiation patch. By changing the on and off voltage of the diode, the radiation beam of the metasurface unit exhibits a phase difference of 180 degrees. It can be seen from the design that, the metasurface array can achieve circular polarization in a certain frequency range, and the gain reaches 19.9 dB when the beam is pointing in the normal direction.