Patent ID: 7423588
Filing Date: 2008-09-09
Classification: H01Q

Abstract:
1. A phased array antenna system generating a directional null comprising: an antenna array having a plurality of spaced antenna units, said antenna units each receiving transmitted signals in a null direction; a transmission line for each said antenna unit; a phasing circuit for each transmission line to receive said transmitted signals from said antenna array, said phasing circuit including: a delay line in at least one of said transmission lines; a first combiner coupled to the output of said one of said transmission lines and one other of said transmission lines, said first combiner configured to combine said received signals into a first output signal; a second combiner coupled to the output of two other of said transmission lines, said second combiner configured to combine said received signals into a second output signal; a generally frequency independent phase inverter receiving said second output signal from said second combiner, said second output signal phase shifted by 180 degrees; and a third combiner configured to receive said first output signal from said first combiner and said phase shifted second output signal from said phase inverter; wherein the amount of delay provided by each said delay line is configured such that said first and second output signals are cancelled by said third combiner, thereby generating said directional null.