Antenna System And Method For Mitigating Multi-Path Effect

• US 20100317309A1
• Filed: 06/15/2010
• Published: 12/16/2010
• Est. Priority Date: 06/15/2009
• Status: Active Grant

• Current Assignee: AGC Automotive Americas R&D, Inc (AGC, Inc.)
• Original Assignee: AGC Automotive Americas R&D, Inc (AGC, Inc.)
• Inventors: LEE, Kwan-ho, LEE, Ming, VILLARROEL, Wladimiro, HORIKI, Yasutaka
• Granted Patent: US 8,515,378 B2
• Time in Patent Office: Days
• US Class Current: 455/296
• CPC Class Codes: H01Q 1/1271 for mounting on windscreens
• CPC Class Codes: H01Q 1/325 characterised by the location of the antenna on the vehicle
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/002 Reducing depolarization effects
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

An antenna system and method utilize a splitter electrically connectable to a single antenna for splitting an RF signal into two signals. A variable phase shifter shifts the phase of one of the signals. A combiner combines the phase shifted and non-phase shifted signals to produce a conditioned signal. A quality examiner circuit changes the amount of phase shift provided by the variable phase shifter to produce a plurality of different conditioned signals. The quality examiner circuit then determines a quality of each conditioned signal and changes the phase shift again to provide the highest quality conditioned signal to a receiver.

Claims

1. An antenna system for mitigating a multi-path effect on a radio frequency (RF) signal received by a single antenna and for providing a conditioned signal to a receiver, said system comprising:

a splitter electrically connectable to the single antenna wherein said splitter splits the RF signal received by the single antenna into a first non-phase shifted signal and a second non-phase shifted signal;

a variable phase shifter electrically connected to said splitter for receiving the second non-phase shifted signal wherein said phase shifter may phase shift the second non-phase shifted signal to produce a phase shifted signal;

a combiner having inputs electrically connected to said splitter and said variable phase shifter for receiving and combining the first non-phase shifted signal and the phase shifted signal to produce the conditioned signal; and

a quality examiner circuit electrically connected to an output of said combiner for receiving the conditioned signal wherein said quality examiner circuit determines a quality of the conditioned signal and communicates with said variable phase shifter for changing an amount of phase shift of the second non-phase shifted signal based on the quality of the conditioned signal thereby modifying the phase shifted signal to mitigate the multi-path effect on the signal.

2. A system as set forth in claim 1 further comprising an analog-to-digital converter (ADC) electrically connected to said combiner and said quality examiner circuit for receiving the conditioned signal from said combiner and providing a digital representation of the conditioned signal to said quality examiner circuit.

3. A system as set forth in claim 2 wherein said quality examiner circuit is further defined as a microprocessor.

4. A system as set forth in claim 2 wherein signal quality is further defined as signal strength.

5. A system as set forth in claim 1 wherein said quality examiner circuit includes an input for receiving the conditioned signal and an output electrically connectable to the receiver for providing the conditioned signal to the receiver.

6. A system as set forth in claim 1 wherein said output of said combiner is electrically connectable to the receiver for providing the conditioned signal to the receiver.

7. A method of conditioning an RF signal received by a single antenna to mitigate a multi-path effect on the RF signal prior to providing a conditioned signal to a receiver, said method comprising the steps of:

splitting the RF signal received by the single antenna into a first non-phase shifted signal and a second non-phase shifted signal;

shifting the phase of the second non-phase shifted signal to produce a first phase shifted signal;

combining the first non-phase shifted signal and phase shifted signal to produce a first conditioned signal;

determining and recording a quality of the first conditioned signal;

shifting the phase of the second non-phase shifted signal to produce a second phase shifted signal different from the first phase shifted signal;

combining the first non-phase shifted signal and the second phase shifted signal to produce a second conditioned signal;

determining and recording a quality of the second conditioned signal;

comparing the quality of the first conditioned signal and the second conditioned signal to determine which of the conditioned signals has a highest quality; and

providing the conditioned signal determined to have the highest quality to the receiver.

8. A method as set forth in claim 7 further comprising the step of shifting the phase of the second non-phase shifted signal to produce a third phase shifted signal different from the first and second phase shifted signals.

9. A method as set forth in claim 8 further comprising the step of combining the first non-phase shifted signal and the third phase shifted signal to produce a third conditioned signal.

10. A method as set forth in claim 9 further comprising the step of determining and recording a quality of the third conditioned signal.

11. A method as set forth in claim 10 wherein said step of comparing the quality is further defined as comparing the quality of the first, second, and third non-phase shifted signals to determine which of the conditioned signals has a highest quality.

12. A method as set forth in claim 11 wherein said step of providing the conditioned signal is further defined as providing the conditioned signal determined to have the highest quality to the receiver.

13. A method as set forth in claim 12 wherein said step of providing the conditioned signal is further defined as shifting the phase of the second non-phase shifted signal to the phase shift associated with the conditioned signal having the highest quality.

14. A method as set forth in claim 7 wherein said step of providing the conditioned signal is further defined as shifting the phase of the second non-phase shifted signal to the phase shift associated with the conditioned signal having the highest quality.

15. An antenna system for mitigating a multi-path effect on a radio frequency (RF) signal and for providing a conditioned signal to a receiver, said system comprising:

a single antenna for receiving the RF signal;

a splitter electrically connectable to said single antenna wherein said splitter splits the RF signal received by said single antenna into a first non-phase shifted signal and a second non-phase shifted signal;

a variable phase shifter electrically connected to said splitter for receiving the second non-phase shifted signal wherein said phase shifter may phase shift the second non-phase shifted signal to produce a phase shifted signal;

a combiner having inputs electrically connected to said splitter and said variable phase shifter for receiving and combining the first non-phase shifted signal and the phase shifted signal to produce the conditioned signal; and

a quality examiner circuit electrically connected to an output of said combiner for receiving the conditioned signal wherein said quality examiner circuit determines a quality of the conditioned signal and communicates with said variable phase shifter for changing an amount of phase shift of the second non-phase shifted signal based on the quality of the conditioned signal thereby modifying the phase shifted signal to mitigate the multi-path effect on the signal.

17. A system as set forth in claim 15 wherein signal quality is further defined as signal strength.

16. A system as set forth in claim 16 further comprising an analog-to-digital converter (ADC) electrically connected to said combiner and said quality examiner circuit for receiving the conditioned signal from said combiner and providing a digital representation of the conditioned signal to said quality examiner circuit.