Wireless communication device and control method for wireless communication device

1. A wireless communication device comprising:

a signal receiver that receives a plurality of signals at different frequencies;

a first oscillator that outputs a first local oscillator signal;

a second oscillator that outputs a second local oscillator signal at a frequency different from a frequency of the first local oscillator signal;

a modulator that generates a plurality of oscillator signals at different frequencies by performing frequency modulation based on the first local oscillator signal and the second local oscillator signal;

a frequency converter that mixes the plurality of local oscillator signals at the different frequencies with the plurality of signals received by the signal receiver; and

a signal processor that performs a predetermined process for the signals which are generated by the mixing of the frequency converter.

2. The wireless communication device according to claim 1 , wherein:

the signal receiver receives two signals at different frequencies; and

the modulator generates two local oscillator signals at different frequencies.

3. The wireless communication device according to claim 2 , wherein

the first local oscillator signal has an intermediate frequency between the two signals at the different frequencies, and the second local oscillator signal has a frequency as a difference between the frequency of the first local oscillator signal and the frequencies of the two signals at the different frequencies.

4. The wireless communication device according to claim 1 , wherein

the modulator generates a local oscillator signal at a frequency as a difference between the frequency of the first local oscillator signal and the frequency of the second oscillator signal and a local oscillator signal at a frequency as a sum thereof.

5. The wireless communication device according to claim 1 ,

wherein the signal receiver receives a plurality of signals at different frequencies or one signal at one single frequency, and

further comprising an oscillator controller that controls either the first oscillator or the second oscillator to oscillate, when the signal receiver receives the one signal at the one single frequency, and controls both the first oscillator and the second oscillator to oscillate, when the signal receiver receives the plurality of signals at the different frequencies.

6. The wireless communication device according to claim 1 ,

wherein the signal receiver receives a plurality of signals at different frequencies and one signal at one single frequency, and

further comprising:

a plurality of connecting switches that are provided respectively between the first oscillator and the modulator and between the second oscillator and the modulator; and

a switch controller that turns one of the connecting switches ON and turns other connecting switch OFF, when the signal receiver receives the one signal at one single frequency, and turns both of the connecting switches ON, when the signal receiver receives the plurality of signals at the different frequencies.

7. The wireless communication device according to claim 6 , wherein

the modulator is a coupler.

8. The wireless communication device according to claim 1 , wherein

the plurality of signals at the different frequencies are included in one frequency band having a preset range of a bandwidth.

9. The wireless communication device according to claim 1 , wherein

the plurality of signals at the different frequencies are included in a plurality of different frequency bands having preset ranges of bandwidths.

10. The wireless communication device according to claim 1 , wherein

the modulator subtracts the plurality of local oscillator signals from the signals at the different frequencies that the signal receiver has received, thereby mixing the signals, and generating intermediate frequencies or baseband signals.

11. A wireless communication device comprising:

a signal receiver that receives a plurality of signals at different frequencies;

a first oscillator that outputs a first local oscillator signal;

a second oscillator that outputs a second local oscillator signal at a frequency different from a frequency of the first local oscillator signal;

a modulator that generates a plurality of local oscillator signals at different frequencies by performing frequency modulation based on the first local oscillator signal and the second local oscillator signal;

a quadrature demodulator that generates baseband signals of the respective plurality of signals received by the signal processor, based on the plurality of local oscillator signals at the different frequencies; and

a signal processor that performs a predetermined process for the baseband signals.

12. The wireless communication device according to claim 11 , wherein:

the signal receiver receives two signals at different frequencies; and

the modulator generates two local oscillator signals at different frequencies.

13. The wireless communication device according to claim 12 , wherein

the first local oscillator signal has an intermediate frequency between the two signals at the different frequencies, and the second local oscillator signal has a frequency as a difference between the frequency of the first local oscillator signal and the frequencies of the two signals at the different frequencies.

14. The wireless communication device according to claim 11 , wherein

the modulator generates a local oscillator signal at a frequency as a difference between the frequency of the first local oscillator signal and the frequency of the second oscillator signal and a local oscillator signal at a frequency as a sum thereof.

15. The wireless communication device according to claim 11 ,

wherein the signal receiver receives a plurality of signals at different frequencies or one signal at one single frequency, and

further comprising an oscillator controller that controls either the first oscillator or the second oscillator to oscillate, when the signal receiver receives the one signal at the one single frequency, and controls both the first oscillator and the second oscillator to oscillate, when the signal receiver receives the plurality of signals at the different frequencies.

16. The wireless communication device according to claim 11 , wherein

the plurality of signals at the different frequencies are included in one frequency band having a preset range of a bandwidth.

17. The wireless communication device according to claim 11 , wherein

the plurality of signals at the different frequencies are included in a plurality of different frequency bands having preset ranges of bandwidths.

18. A control method for a wireless communication device, the method comprising:

receiving a plurality of signals at different frequencies;

outputting a first local oscillator signal;

outputting a second local oscillator signal at a frequency different from a frequency of the first local oscillator signal;

generating a plurality of local oscillator signals at different frequencies by performing frequency modulation based on the first local oscillator signal and the second local oscillator signal;

mixing the plurality of local oscillator signals at the different frequencies with the plurality of signals received by the receiving; and

performing a predetermined process for the signals generated by the mixing.