On the use of dummy elements to match edge elements in transmit arrays

Resistively loaded radiators, known as dummy elements, often are used to improve the active match of receive array edge elements. We discuss the use of dummy elements for transmit array operation and explain that, because these elements do not transmit their own signals, they cannot improve significantly the match of transmitting edge elements. We also discuss two second order effects involving dummy elements: (1) edge element match perturbation from imperfectly matched dummies and (2) perturbation of radiator self-match in an open radiator structure such as a connected array.