Common Mixer Methods and Circuits in Mobile Communication Devices

• US 20090073899A1
• Filed: 11/21/2008
• Published: 03/19/2009
• Est. Priority Date: 10/09/2001
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Wireless Corporation (Kyocera Corporation)
• Inventors: Forrester, Tim
• Granted Patent: US 8,391,820 B2
• Time in Patent Office: Days
• US Class Current: 370/277
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers

Abstract

GPS functionality is added to a wireless communication device in an efficient and cost effective manner. Disclosed is a wireless communications device that has a common mixer constructed to be used for a GPS signal and another signal, a common IF filter constructed to be used for a GPS signal and another signal, in addition to other cost effective embodiments.

Claims

1. In a circuit, a method for converting a GPS (Global Positioning System) signal and a non-GPS RF (radio frequency) signal, said non-GPS RF signal being a non-GPS signal, to a corresponding one of a first intermediate frequency (IF) signal and a second intermediate frequency (IF) signal, comprising:

providing a common mixer that is coupled to receive as inputs a GPS-derived signal that is derived from said GPS signal and a RF-derived signal that is derived from said non-GPS RF signal;

providing a first local oscillator signal having a first frequency and a second oscillator signal having a second frequency to said common mixer; and

producing said first IF signal using said common mixer from said GPS-derived signal and said first oscillator signal when said circuit operates in a GPS mode and a second IF signal using said common mixer from said RF-derived signal and said second local oscillator signal when said circuit operates in a non-GPS RF signal mode.

2. The method of claim 1 wherein said GPS-derived signal is obtained by at least processing said GPS signal through an amplifier.

3. The method of claim 2 wherein said RF-derived signal is obtained by further processing said GPS signal, after being amplified, through a filter.

4. The method of claim 1 wherein said RF-derived signal is obtained by at least processing said non-GPS RF signal through an amplifier.

5. The method of claim 4 wherein said RF-derived signal is obtained by further processing said non-GPS RF signal, after being amplified, through a filter.

6. The method of claim 1 wherein said common mixer receives only one of said GPS-derived signal and said RF-derived signal at any given time responsive to selection by a band select switch.

7. The method of claim 6 wherein said band select switch is controlled by a GPS control signal generator.

8. The method of claim 6 wherein a selection of said first local oscillator signal or said second oscillator signal is controlled by said GPS control signal generator.

9. The method of claim 1 wherein said common mixer receives only one of said GPS-derived signal and said RF-derived signal at any given time responsive to selection by a diplexer circuit.

10. The method of claim 1 wherein said common mixer receives only one of said GPS-derived signal and said RF-derived signal at any given time responsive to selection by a duplexer circuit.

11. The method of claim 1 wherein said first IF signal and said second IF signal are simultaneously produced, said method further including selecting, using a filter, said first IF signal for use by GPS processing circuitry and said second IF signal for use by RF signal processing circuitry.

12. The method of claim 1 wherein said non-GPS RF signal is a cellular signal.

13. A circuit for converting a GPS signal and a non-GPS RF signal to one of a first intermediate frequency (IF) signal and a second intermediate frequency (IF) signal, comprising:

a common mixer coupled to receive as inputs a GPS-derived signal that is derived from said GPS signal and a RF-derived signal that is derived from said non-GPS RF signal, at least one of said GPS-derived signal and said RF-derived signal being available as an input to said common mixer at a given point in time; and

an oscillator circuit for providing one of a first local oscillator signal having a first frequency and a second oscillator signal having a second frequency to said common mixer,

wherein said common mixer is configured to produce said first IF signal from said GPS-derived signal and said first oscillator signal, said common mixer is configured to produce a second IF signal from said non-GPS RF signal and said second local oscillator signal.

14. The circuit of claim 13 wherein said first IF signal is produced by said common mixer when said circuit operates in a GPS mode and wherein said second IF signal is produced by said common mixer when said circuit operates in a non-GPS RF mode.

15. The circuit of claim 13 further including an amplifier wherein said GPS-derived signal is obtained by at least processing said GPS signal through said amplifier.

16. The circuit of claim 15 further including a filter, wherein said RF-derived signal is obtained by further processing said GPS signal, after being amplified, through said filter.

17. The circuit of claim 13 further including an amplifier wherein said RF-derived signal is obtained by at least processing said non-GPS RF signal through said amplifier.

18. The circuit of claim 17 further including a filter wherein said RF-derived signal is obtained by further processing said non-GPS RF signal, after being amplified, through said filter.

19. The circuit of claim 13 wherein said common mixer receives only one of said GPS-derived signal and said RF-derived signal at any given time responsive to selection by one of a band select switch, a diplexer, and a duplexer.

20. In a circuit, a method for converting a GPS (Global Positioning System) signal and a non-GPS RF (radio frequency) signal, said non-GPS RF signal being a non-GPS signal, to a corresponding one of a first intermediate frequency (IF) signal and a second intermediate frequency (IF) signal, comprising:

providing a common mixer that is coupled to receive a mixer input signal, said mixer input signal being at least one of a GPS-derived signal that is derived from said GPS signal and a RF-derived signal that is derived from said non-GPS RF signal;

providing, responsive to a control signal, a local oscillator signal having one of a first frequency and a second frequency to said common mixer;

producing a mixer output signal, using said common mixer, from said local oscillator signal and said mixer input signal; and

filtering said mixer output signal to produce said first IF signal if said circuit operates in a GPS mode and to produce said second IF signal if said circuit operates in a non-GPS RF mode.

21. The method of claim 20 wherein said non-GPS RF signal represents a CDMA signal.