Patent ID: 7593753
Filing Date: 2009-09-22
Classification: H04B,H04W

Abstract:
1. An antenna system for transferring wireless communication signals between a wireless communication device and a base station, the antenna system comprising: a first linear polarization antenna; a second linear polarization antenna oriented perpendicularly to the first linear polarization antenna; a first signal attenuator coupled with the first linear polarization antenna, the first signal attenuator configured to selectively attenuate a first signal associated with the first linear polarization antenna; a second signal attenuator coupled with the second linear polarization antenna, the second signal attenuator configured to selectively attenuate a second signal associated with the second linear polarization antenna; a phase shifter coupled with the first and second signal attenuators and the base station, wherein the phase shifter is configured to induce a 90-degree phase delay in the first signal to generate circular polarization for the antenna system, wherein the phase shifter exhibits a characteristic impedance of 50 ohms; an attenuator controller coupled with the first and second signal attenuators, the attenuator controller configured to control when the first and second signal attenuators attenuate the first signal and the second signal to form a notch in the circular polarization at a range of polarization angles; a first cable coupling the phase shifter with the first signal attenuator, the first cable exhibiting a characteristic impedance of 50 ohms, the first cable comprising a length; a second cable coupling the phase shifter with the second signal attenuator, the second cable exhibiting a characteristic impedance of 50 ohms, the second cable comprising a length substantially equal to the length of the first cable; and a third cable coupling the phase shifter with the base station, the third cable exhibiting a characteristic impedance of 50 ohms.