Multi-band wireless transceiver and method of controlling the same

• US 20060052131A1
• Filed: 09/06/2005
• Published: 03/09/2006
• Est. Priority Date: 09/07/2004
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ichihara, Masaki
• Granted Patent: US 7,664,475 B2
• Time in Patent Office: Days
• US Class Current: 455/552.100
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes

Abstract

A multi-band wireless transceiver having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of the signal-processing paths, includes a band identification circuit for identifying a frequency band, the band identification circuit identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of the multi-band wireless transceiver, and selecting one of the signal-processing paths in accordance with the identified frequency band.

Claims

1. A multi-band wireless transceiver having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of said signal-processing paths,

said multi-band wireless transceiver comprising a band identification circuit for identifying a frequency band, said band identification circuit identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of said multi-band wireless transceiver, and selecting one of said signal-processing paths in accordance with the identified frequency band.

2. The multi-band wireless transceiver as set forth in claim 1, wherein said band identification circuit transmits a control signal by which an active device electrically connected to the selected signal-processing path is allowed to receive power supply.

3. The multi-band wireless transceiver as set forth in claim 1, further comprising a first synthesizer which transmits a local frequency signal for signal reception in accordance with divider data received from said controller, and a second synthesizer which transmits a local frequency signal for signal transmission in accordance with divider data received from said controller, and wherein said band identification circuit receives said divider data for identifying a frequency band.

4. The multi-band wireless transceiver as set forth in claim 3, wherein said band identification circuit, said first synthesizer and said second synthesizer are integrated on a common chip.

5. The multi-band wireless transceiver as set forth in claim 3, wherein said band identification circuit selects a frequency band identified in dependence on divider data received by said first synthesizer, when frequency bands identified in dependence on divider data received by said first and second synthesizers are not coincident with each other.

6. The multi-band wireless transceiver as set forth in claim 3, wherein said band identification circuit turns off a power source providing power to a signal-transmission path, when frequency bands identified in dependence on divider data received by said first and second synthesizers are not coincident with each other.

7. The multi-band wireless transceiver as set forth in claim 3, wherein each of said first and second synthesizers is comprised of:

a reference oscillator which transmits a reference frequency signal;

a voltage controlled oscillator which transmits said local frequency signal;

an R-divider which divides said reference frequency signal by R wherein R indicates a number equal to or greater than two;

an N-divider which divides said local frequency signal by N wherein N indicates a number equal to or greater than two;

a phase-detector which compares a phase of a signal divided by said R-divider to a phase of a signal divided by said N-divider, and transmits a phase-difference signal indicating a difference between said phases;

a charge pump which generates a voltage in dependence on said phase-difference signal, and carries out negative feed-back control to an oscillation frequency of said voltage controlled oscillator;

an R-register which picks R-divider data directed thereto out of divider data received from said controller, and transmits the R-divider data to both said R-divider and said band identification circuit; and

an N-register which picks N-divider data directed thereto out of divider data received from said controller, and transmits the N-divider data to both said N-divider and said band identification circuit.

8. The multi-band wireless transceiver as set forth in claim 3, wherein each of said first and second synthesizers is comprised of:

a plurality of voltage controlled oscillators transmitting signals having different frequency ranges from one another; and

a switch for selecting one of said voltage controlled oscillators,

said band identification circuit transmitting a control signal indicative of a certain voltage controlled oscillator among said voltage controlled oscillators, to said switch in accordance with a frequency band identified based on said divider data.

9. The multi-band wireless transceiver as set forth in claim 1, wherein each of said signal-processing paths is comprised of a first path for processing a received signal, and a second path for processing a signal to be transmitted,

said first path being comprised of:

a plurality of duplexers each in association with each of said frequency bands;

an antenna switch through which a wireless frequency signal received through an antenna is transmitted to the associated duplexer among said duplexers;

a plurality of low-noise amplifiers each in association with each of said frequency bands for amplifying signals output from said duplexers;

a plurality of first filters each in association with each of said frequency bands for removing frequency bands other than the associated frequency band in the amplified signals; and

a switch through which one of signals output from said first filters is transmitted to a common base band demodulator,

said second path being comprised of

a plurality of driver amplifiers each in association with each of said frequency bands for amplifying a wireless frequency signal having been modulated in accordance with a base band signal;

a plurality of second filters each in association with each of said frequency bands for removing spurious parts existing out of a frequency band in the amplified wireless frequency signal;

a plurality of power amplifiers each in association with each of said frequency bands for amplifying wireless frequency signals output from said second filters; and

a plurality of isolators each in association with each of said frequency bands for transmitting said wireless frequency signals to said antenna through each of said duplexers and said antenna switch.

10. A method of controlling a multi-band wireless transceiver having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of said signal-processing paths, comprising the steps of:

(a) identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of said multi-band wireless transceiver; and

(b) selecting one of said signal-processing paths in accordance with the identified frequency band.

11. The method as set forth in claim 10, wherein said frequency band is identified in said step (a) in accordance with divider data transmitted from said controller.

12. The method as set forth in claim 10, wherein when frequency bands identified in dependence on divider data received through signal-transmission path and signal-reception paths are not coincident with each other, a frequency band identified in dependence on divider data received through signal-reception path is selected.

13. The method as set forth in claim 10, wherein when frequency bands identified in dependence on divider data received through signal-transmission path and signal-reception paths are not coincident with each other, a power source providing power to a signal-transmission path is turned off.

14. A program for causing a computer to carry out a method of controlling a multi-band wireless transceiver having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of said signal-processing paths, steps executed by said computer in accordance with said program including:

(a) identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of said multi-band wireless transceiver; and

(b) selecting one of said signal-processing paths in accordance with the identified frequency band.

15. A mobile communication terminal comprising:

an antenna;

a controller which controls an operation of said mobile communication terminal;

a wireless signal processor which processes wireless signals having been received through said antenna and signals to be transmitted through said antenna, under control of said controller;

a microrhone through which a user inputs voice signals into said controller;

a speaker through which a user listens to voice signals having been received through said antenna and having been processed in said wireless signal processor;

a keyboard through which a user transmits commands into said controller; and

a display on which images and data are displayed under control of said controller,

said wireless signal processor including a multi-band wireless transceiver having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of said signal-processing paths,

said multi-band wireless transceiver comprising a band identification circuit for identifying a frequency band, said band identification circuit identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of said multi-band wireless transceiver, and selecting one of said signal-processing paths in accordance with the identified frequency band.

16. The mobile communication terminal as set forth in claim 15, wherein said band identification circuit transmits a control signal by which an active device electrically connected to the selected signal-processing path is allowed to receive power supply.

17. The mobile communication terminal as set forth in claim 15, wherein said band identification circuit further includes a first synthesizer which transmits a local frequency signal for signal reception in accordance with divider data received from said controller, and a second synthesizer which transmits a local frequency signal for signal transmission in accordance with divider data received from said controller, and wherein said band identification circuit receives said divider data for identifying a frequency band.

18. The mobile communication terminal as set forth in claim 17, wherein said band identification circuit, said first synthesizer and said second synthesizer are integrated on a common chip.

19. The mobile communication terminal as set forth in claim 17, wherein said band identification circuit selects a frequency band identified in dependence on divider data received by said first synthesizer, when frequency bands identified in dependence on divider data received by said first and second synthesizers are not coincident with each other.

20. The mobile communication terminal as set forth in claim 19, wherein said band identification circuit turns off a power source providing power to a signal-transmission path, when frequency bands identified in dependence on divider data received by said first and second synthesizers are not coincident with each other.

21. The mobile communication terminal as set forth in claim 17, wherein each of said first and second synthesizers is comprised of:

a reference oscillator which transmits a reference frequency signal;

a voltage controlled oscillator which transmits said local frequency signal;

an R-divider which divides said reference frequency signal by R wherein R indicates a number equal to or greater than two;

an N-divider which divides said local frequency signal by N wherein N indicates a number equal to or greater than two;

a phase-detector which compares a phase of a signal divided by said R-divider to a phase of a signal divided by said N-divider, and transmits a phase-difference signal indicating a difference between said phases;

a charge pump which generates a voltage in dependence on said phase-difference signal, and carries out negative feed-back control to an oscillation frequency of said voltage controlled oscillator;

an R-register which picks R-divider data directed thereto out of divider data received from said controller, and transmits the R-divider data to both said R-divider and said band identification circuit; and

an N-register which picks N-divider data directed thereto out of divider data received from said controller, and transmits the N-divider data to both said N-divider and said band identification circuit.

22. The mobile communication terminal as set forth in claim 17, wherein each of said first and second synthesizers is comprised of:

a plurality of voltage controlled oscillators transmitting signals having different frequency ranges from one another; and

a switch for selecting one of said voltage controlled oscillators, said band identification circuit transmitting a control signal indicative of a certain voltage controlled oscillator among said voltage controlled oscillators, to said switch in accordance with a frequency band identified based on said divider data.

23. The mobile communication terminal as set forth in claim 15, wherein said mobile communication terminal is comprised of a mobile phone.

24. The mobile communication terminal as set forth in claim 23, wherein said mobile phone is comprised of a foldable mobile phone.

25. A program for causing a computer to carry out a method of controlling a multi-band wireless transceiver in a mobile communication terminal, having a plurality of signal-processing paths, and further having a function of making wireless communication through a plurality of frequency bands by selecting one of said signal-processing paths, steps executed by said computer in accordance with said program including:

(a) identifying a frequency band in dependence on a frequency-band information received from a controller which controls an operation of said multi-band wireless transceiver; and

(b) selecting one of said signal-processing paths in accordance with the identified frequency band.