Can Series or Parallel Switches Improve the Performance of Reconfigurable Reflectarray Elements?

This paper employs microwave network analysis to theoretically show that the performance limit of 1-bit reconfigurable reflectarray (RRA) elements only depends on the imaginary/real impedance ratio of a single switch state and the ON/OFF impedance ratio between two switch states. Crucially, the performance limit is found to be independent of the absolute impedance values of the switches. Furthermore, it is demonstrated that series or parallel identical switches CANNOT improve the performance of RRA elements, challenging conventional methods of combining identical switches for performance improvement, and offering new insights into the design and optimization of RRA elements.