Analysis of the Transmission Performance Limits for a Multilayer Transmitarray Unit Cell.

This communication presents a theoretical study that establishes the performance limits for a multilayer transmitarray unit cell. This is the first study to be applicable to unit cells in which the conducting resonators, on the different layers, are shaped differently. A theoretical calculation is derived at the beginning. The theoretical calculations predict that, for an S21 amplitude of −1 dB, unit cells having two and three conducting layers provide a phase shifting range of 170° and 360°, respectively. In addition, for a given phase shifting range of S21, a new methodology for analyzing the maximum S21 amplitude, based on different substrates, is proposed. For the first time, we prove that it is efficient to attain the maximum S21 amplitudes by employing a smaller substrate permittivity or a quarter-of-wavelength substrate electrical thickness. Finally, the theoretical calculations have been validated through computer simulation. [ABSTRACT FROM AUTHOR]