Analysis and Simulation of Twist Reflector Antenna at Different Incident Angles

Twist-Reflector antennas are among widely-used structures in the construction of reflective antennas and dual antennas. These antennas are often used to rotate the polarization of the radiative electromagnetic wave. Despite wide usage of these antennas, their malfunctions such as linear state outage of reflective wave and increase in cross-polarization have not been discussed much. The performance of this type of antenna is desirable in vertical radiation angles, but by rotating the antenna and giving it some angle with vertical line, the antenna does not perform well. In this paper, effective factors in malfunctions of this type of antenna are discussed and mathematical formulas for measuring undesirable polarization and phase difference occurred in different angles of rotation of the antenna are obtained. Validation of the method is evaluated by simulations in CST software environment at 3 GHz frequency.