ISM band active array with electronically controlled element weighting

Abstract

A four-element active array with electronically controlled element weighting is presented. This active array consists of variable gain active antennas with gain control accomplished through changing the amplifier biasing. Matching across the transistor bias range is implemented by judiciously incorporating varactor diodes in the matching circuits in order to ensure good input and output match. This active array is capable of forming a desired radiation pattern via tuning the appropriate amplitude and phase control voltages. Examples of measured radiation pattern for this active array, shaped using some of the standard antenna pattern synthesis methods, are also presented. These radiation patterns agreed well with those predicted by simulation within the limits of experimental results.