Time-switched arrays and reflect-arrays

The concept of using time as an additional parameter, or a fourth dimension, in the design and control of array antennas was first proposed by Shanks and Bickmore in the late 1950s. The fundamental principle of a time-modulated, or time-switched, array is to periodically energize the elements of the array by switching each element on and off using high speed RF switches in such a way that the pattern radiated by the array conforms to a prescribed function.