Coupled Slots Varactor-Tuned Unit Cell for Single Linear Polarization Reflectarrays at C-Band

This paper presents a C-band single linear polarization reconfigurable phase-shifting cell. It consists of five rectangular coupled slots loaded with one variable capacitance in order to control the reflected phase. This variable capacitance is modelled with a lumped element, typically representing a surface mount varactor diode. A biasing line is also considered to isolate the RF signal from DC. Simulations demonstrate the superiority of this unit cell to its counterparts in terms of phase-range, bandwidth and robustness against oblique angle of incidence. In addition, numerical results show the ability of the unit cell to tilt the main beam of a circular array by 25° off broadside direction.