X-band Rectangular to Square Waveguide Transition for Transmitarray Unit Cell Characterization

In this paper, a characterization setup for transmitarray unit cell analysis is designed in CST studio using rectangular to square waveguide transition for X-band applications. A wideband transmitarray unit cell is designed using split ring resonator and unit cell simulations show wide impedance matching bandwidth of 43.7%. In this simulation, the waveguide transition length is varied to reduce the reflection coefficient magnitudes below -20dB. Then, the square cross section area of waveguide is made variable and cutoff frequency variation over 4GHz is illustrated. Finally, the model for real time test setup is simulated along with the transmitarray unit cell and the results show high transmission magnitude of -O.23dB. This setup can also be used for other frequency selective surface unit cells characterization.