ACTIVE PHASED ARRAY AT ISM BAND

Abstract

A four-element receive mode rectangular microstrip patch active phased array operating in the 2.4GHz ISM band is constructed using variable gain LNAs and linear phase 360° phase shifters to attain independent amplitude and phase control in each branch of the array. This active array eliminates the use of attenuators for the purpose of gain control by effectively leveraging the inherent functionality in variable gain amplifiers. It has the capability of synthesizing the desired radiation pattern by simply tuning its amplitude and phase control voltages. These control voltages can be controlled by a DSP processor, thus forming an adaptive array. This array is therefore suitable for use in the field testing of DSP algorithms that are developed for adaptive arrays. Measured radiation patterns, through fix tuning the terminal control voltages of this active phased array, generally agree well with simulated results except at the null points, side and back lobes.