Design of Reflectarray Unit Cell Based on Varactor Diode for Weather Radar Applications

In this paper, a linear polarization phase-shifting unit cell structure is proposed for reconfigurable reflectarray antenna intended for weather surveillance applications within the X-band frequency range. The simulated unit cell structure consists of two symmetrical parts, each of them comprises two concentric half square rings surrounding a half of square patch. The two halves are connected together through a variable capacitor, which achieves a wide phase range of 313 degrees under normal incidence illumination, with around 1.5 dB of losses. The obtained simulation findings, validate the performance of the proposed unit cell, emphasizing its suitability for advanced reflectarray antenna systems, promising for low-cost radar applications.