  Significant radar range degradation can be incurred due to variations in
antenna impedance from changing array scan angle. Element-wise reconfigurable
impedance tuners can be used to optimally match the power amplifier device;
however, the impedance matching can also affect the array pattern. In this
paper, the effects of element-wise impedance tuning on the transmitted power
and on the array pattern are studied, and an approach is recommended for the
element-wise implementation of impedance tuners. Examples of impact on array
pattern and transmitted power are given using simulation of a designed
switched-stub impedance tuner. As a result of these experiments, guidelines are
developed for the creation of real-time circuit optimization techniques in the
array elements.
