Feed-point reflection coefficient of an element in a scanning antenna array: time-domain measurements

A linear array of five radiating apertures with separate feed ports is used to illustrate the variation of reflection coefficient at the central port with variation of scan angle from zero to 54° over the frequency range from 0.6 to 6 GHz. Two different time-domain methods, showing excellent agreement for the determination of reflection coefficient, are employed. Indirect determination, by summing the separate components coupled from one aperture to another, is shown to be preferable.