Patent ID: 6175327
Filing Date: 2001-01-16
Classification: H01Q,H04B

Abstract:
A global positioning system (GPS) receiver for reducing a contribution of an interference signal while receiving a composite signal that includes said interference signal and at least one circularly-polarized GPS signal wherein said interference signal propagates along an associated interference signal path, the receiver comprising:an antenna having a reference antenna element and a plurality of auxiliary antenna elements arranged across an antenna array wherein each antenna element generates a single output signal in response to all polarization components of said GPS signal and, in response to said composite signal, said reference antenna element provides a reference signal and said auxiliary antenna elements provide auxiliary signals which each has a phase difference from said reference signal that is a function of its respective auxiliary antenna element's location in said antenna array and of said interference signal path;a plurality of phase shifters that are each coupled to vary the phase of a respective one of said auxiliary signals;a power combiner coupled to said reference antenna element and to said phase shifters to combine said reference signal and said auxiliary signals into a combined signal;a downconverter that reduces the frequency of said combined signal;a digital GPS processor; andan analog-to-digital converter (ADC) that couples said downconverter to said GPS processor;said phase shifters facilitating phase adjustment of at least one of said auxiliary signals to thereby reduce the amplitude of said combined signal and thereby reduce said contribution of said interference signal.