JPH09294089A - Frequency synthesizer circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the size small and to reduce the power consumption. SOLUTION: The circuit 12 has 1st and 2nd local oscillation sections 13, 14, a 1/M frequency divider circuit 15 and a 1/N frequency divider circuit 16. The 1st local oscillation section 13 generates a 1st local oscillation signal. In a transmitter side, the signal is mixed to a carrier signal modulated by a base band signal and a transmission frequency signal is generated. At a receiver side, the 1st local oscillation signal is mixed with a reception frequency signal and the reception frequency signal is frequency-converted into a 1st IF signal. The 2nd local oscillator section 14 generates a 2nd local oscillation signal, at the transmitter side, the signal is subject to 1/M frequency division by the 1/M frequency divider circuit 15 and the result is used as the carrier signal, and at the receiver side, the signal is subject to 1/N frequency division by the 1/N frequency divider circuit 16 and mixed in the 1st IF signal and a 2nd IF signal is obtained. Information such as voice and data is obtained by demodulating the 2nd IF signal. Since three frequencies fL1, fL2, fL3 are obtained by the two local oscillator sections 13, 14, the circuit is made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency synthesizer circuit used in a radio device for transmitting and receiving a frequency signal such as a mobile communication device, a PHS telephone, a satellite communication device and the like.

[0002]

2. Description of the Related Art A frequency synthesizer circuit has been conventionally used for a wireless device having a transmitting / receiving function. In such a radio device, various frequency signals generated by the frequency synthesizer circuit are used to generate a transmission frequency signal from an information signal such as voice or data, and the reception frequency signal is frequency-converted into a predetermined frequency to obtain the information signal. Is getting

[Structure of Radio Device] FIG. 9 shows a radio device and a conventional frequency synthesizer circuit used in the radio device. In FIG. 9, the frequency synthesizer circuit 1 includes a first local oscillator 2, a second local oscillator 3, a third local oscillator 4, which generate local oscillator signals of different frequencies {fL1, fL2, fL3}, and a temperature oscillator. It is composed of a compensation crystal oscillator (hereinafter referred to as TCXO) 5. The first local oscillator 2 is a voltage-controlled frequency variable oscillator (hereinafter referred to as VC
It is a phase-locked loop (hereinafter referred to as PLL) including an O) 21, a prescaler 22, a frequency dividing circuit 23, and a phase comparison circuit 24, and generates a first local oscillation signal. The second local oscillator 3 is the first local oscillator 2
Similarly to VCO 31, prescaler 32, frequency divider 3
3 and a phase comparison circuit 34, and generates a second local oscillation signal used as a carrier signal on the transmission side of the wireless device. Similarly to the above, the third local oscillation unit 4 also includes the VCO 41, the prescaler 42, and the frequency dividing circuit 4.
3 and a phase comparison circuit 44, which is a PLL and generates a third local oscillation signal used on the receiving side of the wireless device.

On the transmission side of the wireless device, the waveform generation circuit 6 is a circuit for generating a waveform of a baseband signal based on an information signal including digital and analog data such as voice and various data. The modulation circuit 7 is a circuit that modulates the second local oscillation signal supplied as a carrier signal from the second local generation unit 3 with a baseband signal. The up converter 8 also mixes the modulation signal output from the modulation circuit 7 and the first local oscillation signal from the first local oscillation unit 2 to generate a transmission frequency signal.

A first down converter 9 is provided on the receiving side of the wireless device, and the first down converter 9 is provided.
Mixes the first local oscillation signal from the first local oscillation unit 2 with the reception frequency signal to obtain the reception frequency (for example, several GH).
Z) is downconverted to a first intermediate frequency (eg, 100 MHz). A second down converter 10 is further provided on the output side of the first down converter 9. The second down converter 10 receives the first intermediate frequency signal (hereinafter referred to as the first intermediate frequency signal) supplied from the first down converter 9.
A second intermediate frequency signal (hereinafter referred to as a second IF signal) having a second intermediate frequency (for example, 500 kHz) obtained by mixing the third local oscillation signal supplied from the third local oscillator 4 with the IF signal). To the demodulation circuit 11. The demodulation circuit 11 demodulates the supplied second IF signal according to the modulation method to obtain an information signal such as voice or data.

[Operation of Radio Apparatus] Next, the operation of the radio apparatus shown in FIG. 9 will be described.

(1) Transmission The first local oscillator 2 operates and the VCO 21 outputs a first local oscillation signal having a frequency fL1 of {reception frequency fs ± first intermediate frequency fIF1}. The first local oscillation signal is supplied to the up converter 8 and the first down converter 9, respectively.

In addition, the operation of the second local oscillator 3 causes VC
From O31, {transmission frequency ft-first local oscillation frequency f
L1} or {first local oscillation frequency fL1-transmission frequency ft}
The second local oscillation signal having the frequency fL2 is output, and this signal is supplied to the modulation circuit 7 as a carrier signal of the information signal. The modulation circuit 7 modulates the carrier signal with the baseband signal from the waveform generation circuit 6, and sends the obtained modulation signal to the up converter 8. Up converter 8
Mixes the modulation signal with the first local oscillation signal (fL1) from the first local oscillation section 2 to obtain a predetermined transmission frequency ft.
A transmission modulation wave (for example, several GHz) is generated and output to a communication station or the like.

(2) Reception The predetermined reception frequency signal (fr) supplied from the antenna (not shown) to the first down converter 9 via the high frequency amplifier circuit is transmitted to the first down converter 9 as described above. The first intermediate frequency fIF is mixed with the first local oscillation signal (fL1) supplied from the local oscillator 2.
Frequency converted to 1. The first IF signal obtained by the frequency conversion is sent to the second down converter 10, where the first IF signal is the VCO 41 of the third local oscillator 4.
It is mixed with the third local oscillation signal (fIF3) output from. Here, the third local oscillation signal has a frequency fL3 of {first intermediate frequency fIF1 ± second intermediate frequency fIF2}, and by mixing the third local oscillation signal (fL3) and the first IF signal, The first IF signal (fIF1) is
Down-converted to the second intermediate frequency fIF2. The second IF signal (fIF2) thus obtained is supplied to the demodulation circuit 11, where it is demodulated and an information signal is obtained.

[0010]

As described above, conventionally,
In the frequency synthesizer circuit 1 used in the wireless device, three types of frequency signals, here, the local oscillation signal (fL
1, fL2, fL3), three local oscillators 2,
It has 3 and 4, respectively. However, there is a problem that it is difficult to reduce the size of each local oscillator, and it is also difficult to reduce the power consumption of each local oscillator. In addition, in wireless devices such as mobile phones, downsizing and power saving are required. Therefore, there is a problem in that the circuit configuration in which the oscillating unit is provided by the number of required frequency signals as in the related art cannot meet the demands for downsizing of the entire device, power saving, and the like.

The present invention has been made to solve such a problem, and an object thereof is to obtain a frequency synthesizer circuit capable of efficiently generating a plurality of frequency signals with a minimum frequency generating section.

[0012]

In order to achieve the above object, a frequency synthesizer circuit according to the present invention generates a transmission frequency signal based on an information signal, transmits the transmission frequency signal, and transmits the information based on the reception frequency signal. It is used in a radio device for extracting a signal and has a first frequency signal generation section and a second frequency signal generation section. And a first frequency signal and a second frequency signal or a signal created based on the second frequency signal,
Is used to generate a transmission frequency signal, and an information signal is extracted from the reception frequency signal.

The first frequency signal from the first frequency generator is mixed at the transmitting side with a modulated signal modulated based on the information signal to generate a transmitting frequency signal, and at the receiving side, the receiving frequency signal is generated. The reception frequency signal is frequency-converted into the first intermediate frequency signal by being mixed with the first intermediate frequency signal. Further, the second frequency signal from the second frequency generator or a signal created based on this second frequency signal is used as a carrier signal on the transmitting side and obtained from the receiving frequency signal on the receiving side. First
The first intermediate frequency signal is frequency-converted into the second intermediate frequency signal by being mixed with the intermediate frequency signal.

The frequency synthesizer circuit according to the present invention performs the "division" or "multiplication" processing on the second frequency signal output from the second frequency generating section to obtain the second frequency signal from the second frequency signal. Generate signals of different frequencies.

As a concrete configuration, for example, on the transmitting side, the second frequency signal that has been divided by M or multiplied by M is
A transmission frequency signal is generated by modulating the carrier signal and mixing the first frequency signal with the obtained modulation signal. Also, on the receiving side, the second frequency signal, which has been divided by N or multiplied by N, is mixed with the signal obtained by frequency-converting the received frequency signal with the first frequency signal, and obtained by this frequency conversion. The signal is further frequency converted.

In the above structure, the second frequency generator is M times (or 1 / M) the frequency of the carrier signal.
And generating the second frequency signal having a frequency equal to the first intermediate frequency ± N times (or 1 / N) the second intermediate frequency.

Further, as another concrete configuration, the second frequency signal is divided by M to divide by M (or M is multiplied by M), or N is divided by N (or). N frequency multiplication second frequency signal (or M frequency multiplication second) on the transmitting side.
The frequency signal) or the second frequency signal is used as a carrier signal, and the transmission frequency signal is generated based on the carrier signal.
At the receiving side, the second frequency signal or the N-divided second frequency signal (or N times the second frequency signal) is further mixed with the signal obtained by frequency-converting the received frequency signal with the first frequency signal. Then, the frequency is converted.

In the above configuration, the second frequency generator is M times (or 1 / M) the frequency of the carrier signal, and
Generate a second frequency signal having a frequency equal to the first intermediate frequency ± the second intermediate frequency. Alternatively, the second frequency generator is equal to the frequency of the carrier signal and is N times (or 1 / n) the difference between the first intermediate frequency and the second intermediate frequency.
Generating a second frequency signal having a frequency of N).

Further, in the frequency synthesizer circuit of the present invention, the variable frequency dividing section or the variable frequency multiplying section capable of arbitrarily switching the frequency dividing value or the frequency multiplying value for the second frequency signal from the second frequency generating section. It is also possible to adopt a configuration having.

Further, it has a signal generator for generating two frequency signals having mutually orthogonal phase components from the second frequency signal from the second frequency generator or a signal generated based on the second frequency signal. It is also possible to employ a configuration in which two frequency signals are used as carrier signals and the carrier signals are modulated by the information signals.

As described above, the first and second frequency generators (corresponding to the first and second local oscillators in the embodiment) are provided, and the second frequency signal output from the second frequency generator, that is, By dividing or multiplying the second local oscillation signal, two types of frequency signals (carrier signal and third local signal) can be generated in addition to the first frequency signal. Therefore, it is possible to realize a frequency synthesizer circuit that can generate a desired transmission frequency signal and extract signals such as voice and data from a predetermined reception frequency signal by using only the first and second frequency generators. Therefore, when used as a frequency synthesizer circuit of a wireless device, it is possible to contribute to downsizing of the entire device and power saving.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.
The same reference numerals are given to the portions corresponding to the drawings already described, and the description thereof will be omitted.

Embodiment 1. FIG. 1 is a first embodiment of the present invention.
FIG.

[Structure] In the figure, 5 is a TCXO, 6 is a waveform generation circuit, 7 is a modulation circuit, 8 is an up converter,
Reference numeral 9 is a first down converter, 10 is a second down converter, and 11 is a demodulation circuit, which corresponds to those in FIG.

In the first embodiment, the local oscillating unit in the frequency synthesizer circuit 12 is composed of two types, the first local oscillating unit 13 and the second local oscillating unit 14. Further, an M divider 15 and an N divider 16 are provided on the output side of the second local oscillator 14.

The first local oscillating unit 13 is composed of a VCO 131, a prescaler 132, a frequency dividing circuit 133 and a PLL by a phase comparing circuit 134, and generates a first local oscillating signal (fL1). In addition, the second local oscillator 14
Is composed of a VCO 141, a prescaler 142, a frequency dividing circuit 143, and a PLL by a phase comparison circuit 144, and generates a second local oscillation signal of frequency fL2. The second frequency signal (fL2) is supplied to the M frequency dividing circuit 15
Is divided by M and supplied to the modulation circuit 7 as a carrier signal (fC), and divided by N by the N dividing circuit 16 and supplied to the second down converter 10 as a third local signal (fL3).

[Operation] When the first local oscillator 13 operates, the VCO 131 outputs a first local oscillation signal having a frequency fL1 of {transmission frequency ft ± carrier signal frequency fC}. The first local oscillation signal (fL1) is supplied to the up converter 8 on the transmission side and the first down converter 9 on the reception side.

(1) Transmission On the transmission side, the operation of the second local oscillation section 14 causes the VCO 141 to output the second local oscillation signal. This second local oscillation signal is {(transmission frequency ft-first local oscillation frequency fL1) × M} or {(first local oscillation frequency fL1
A transmission frequency ft) × M} and a frequency {(first intermediate frequency fIF1 ± second intermediate frequency fIF2) × N}. The second local oscillation signal is input to the M frequency dividing circuit 15 and the N frequency dividing circuit 16 and divided by the M frequency dividing circuit 15, and the frequency divided signal is sent to the modulation circuit 7 as a carrier signal (fC). Is entered. The waveform generation circuit 6 generates a desired baseband signal based on the information signal and supplies it to the modulation circuit 7. The modulation circuit 7 modulates the carrier signal (fC) by this baseband signal and sends it to the up converter 8 as a modulation signal. The up-converter 8 mixes the modulation signal with the first local oscillation signal (fL1) supplied from the first local oscillation section 13 to generate a transmission modulation wave at a predetermined transmission frequency ft, that is, a transmission frequency signal. The transmission frequency signal is transmitted to the partner station or the like.

(2) Reception A reception frequency signal (fr) of about several GHz is received by an antenna and amplified to a predetermined level by an amplifier circuit (not shown).
) Is mixed with the first local oscillation signal (fL1) in the first down converter 9, and the first intermediate frequency fIF1
The frequency is converted into the first IF signal (for example, 100 MHz) and is sent to the second down converter 10.

The second local oscillation signal (fL2) output from the second local oscillating unit 14 is divided by N in the N frequency dividing circuit 16 to obtain {first intermediate frequency fIF1 ± second intermediate frequency fIF1.
A signal having a frequency fL3 of 2} (hereinafter referred to as a third local signal) is generated and supplied to the second down converter 10.

The second down converter 10 mixes the first IF signal supplied from the first down converter 9 and the third local signal (fL3), and converts the first IF signal to a second intermediate frequency fIF2 (for example, 500 kHz). Convert frequency. The second IF signal obtained by this frequency conversion is
It is supplied to the demodulation circuit 11 and demodulated, and information such as voice and data is obtained.

As described above, in the first embodiment, the frequency signals (fL1,
fC, fL3) can be easily generated. Therefore, if a wireless device such as a mobile phone is configured using the frequency synthesizer circuit 12, the device can be downsized and the power consumption can be reduced.

In the above configuration, the transmission frequency ft is set as one parameter for the first local oscillation signal and the second local oscillation signal, but the reception frequency fr may be used as a parameter instead of the transmission frequency ft.

Embodiment 2. The feature of the second embodiment is that the frequency synthesizer circuit has two local oscillators and either one of the M divider circuit or the N divider circuit. 2 and 3, the configuration in which the M frequency dividing circuit is provided (configuration 1) and the configuration in which the N frequency dividing circuit is provided (configuration 2) will be described below.

[Structure 1] FIG. 2 shows a frequency synthesizer circuit according to Structure 1 and a radio apparatus using the same. In the configuration 1, as in the first embodiment, the frequency synthesizer circuit 17 includes two local oscillation units (first local oscillation unit 13,
It has a second local oscillator 18). Further, an M divider circuit 15 is provided on the output side of the second local oscillator 18. The second local oscillator 18 includes a VCO 181, a prescaler 182, a frequency dividing circuit 183, and a phase comparison circuit 18.
The second local oscillation signal (fL2) is output from the VCO 181.

The second local oscillation signal (fL2) generated by the second local oscillator 18 is {(transmission frequency ft-frequency fL1 of the first local oscillation signal) * M times} (M is, for example, 4) or {( Frequency fL1 of first local oscillation signal-transmission frequency ft)
× M times}. Therefore, the second local oscillation signal (fL2) output from the second local oscillation unit 18 is M
When the frequency is divided by M in the frequency dividing circuit 15, it becomes the frequency fC of a predetermined carrier signal and is supplied to the modulating circuit 7 as a carrier signal. Then, as in the first embodiment, the modulation circuit 7 modulates the baseband signal, and the obtained modulation signal is mixed with the first local oscillation signal (fL1) by the upconverter 8 to generate the transmission frequency. A signal (ft) is transmitted by the wireless device.

The frequency fL2 of the second local oscillation signal is
The frequency is set to be equal to {first intermediate frequency fIF1 ± second intermediate frequency fIF2}. Therefore, the second local oscillation signal (fL2) is directly supplied to the second down converter 10 as the third local signal (fL3). The second down converter 10 converts the first IF signal obtained by frequency-converting the reception frequency signal (fr) into the third local signal (f
L3) down-converts to a predetermined second intermediate frequency fIF2. Then, the second IF signal is demodulated by the demodulation circuit 11 to obtain an information signal.

[Structure 2] FIG. 3 shows a frequency synthesizer circuit according to Structure 2 and a radio apparatus using the same. As shown in FIG. 3, in the configuration 2, the frequency divider 16 is provided on the output side of the second local oscillator 50 of the frequency synthesizer circuit 19, and divides the second local oscillation signal by N to generate the third local oscillator. The signal (fL3) is used, and the second local oscillation signal is used as it is as the carrier signal.

The second local oscillating unit 50 is composed of a VCO 51, a prescaler 52, a frequency dividing circuit 53, and a PLL by a phase comparing circuit 54, as in the other embodiment and configuration 1, and the second local oscillating signal from the VCO 51. (FL2) is output.

The second local oscillation signal generated by the second local oscillation unit 50 has a frequency of {transmission frequency ft-frequency of first local oscillation signal fL1} or {frequency of first local oscillation signal fL1-transmission frequency ft}. It has fL2 and a frequency of {(first intermediate frequency fIF1 ± second intermediate frequency fIF2) × N times}. Therefore, the second local oscillation signal (fL2) is
On the transmitting side, the carrier signal (fC) is directly supplied to the modulation circuit 7, while on the receiving side, it is frequency-divided into a third local signal (fL3). Then, this third local signal is supplied to the second down converter 10.

2 and 3, the local oscillation signal (fL generated by the two local oscillation units 13 and 18 (50) is generated also in the second embodiment.
It is possible to transmit and receive a signal based on 1, fL2). In addition, in this embodiment, in addition to the two local oscillators,
Since it is configured by providing either the M frequency dividing circuit or the N frequency dividing circuit, it is more advantageous in terms of circuit miniaturization.

Embodiment 3 In the first and second embodiments,
Although the configuration has been described in which the second local oscillation signal is divided by M and N, or only one of them is divided, the second local oscillation signal may be divided by M and N times. FIG. 4 is a diagram showing the configuration of the third embodiment in which the second local oscillation signal is multiplied in this way.

As shown in FIG. 4, the frequency synthesizer circuit 20 includes a first local oscillator 13, a second local oscillator 60 and a TCXO 5, and an M multiplier circuit 25 on the output side of the second local oscillator 60. , N multiplication circuit 26 is provided. The second local oscillator 60 includes a VCO 61,
Prescaler 62, frequency divider 63 and phase comparator 64
, And a second local oscillation signal (fL2) is output from the VCO 61.

The frequency fL2 of the second local oscillation signal is {(transmission frequency ft-frequency fL1 of the first local oscillation signal) ÷ M}.
Or {(the frequency fL1 of the first local oscillation signal−the transmission frequency f
t) ÷ M} and {(first intermediate frequency f
IF1 ± second intermediate frequency fIF2) ÷ N}.

The second local oscillation signal is input to the M multiplication circuit 25 on the transmission side, and its frequency is multiplied by M,
It is input to the modulation circuit 7 as a carrier signal (fC). The modulation circuit 7 modulates this carrier signal with the baseband signal and sends it to the up converter 8. Up converter 8
Uses the first local oscillation signal (fL1) output from the first local oscillator 13 to up-convert the modulated signal into a predetermined transmission frequency signal (ft).

The second local oscillation signal is supplied to the N multiplication circuit 26 on the receiving side and multiplied by N. As a result, a third local signal having a frequency fL3 of {first intermediate frequency fIF1 ± second intermediate frequency fIF2} is generated and supplied to the second down converter 10. Second down converter 1
0 mixes the third local signal with the first IF signal generated by down-converting the reception frequency signal (fr), whereby the first IF signal is frequency-converted into the second IF signal and supplied to the demodulation circuit 11. Then, the desired information signal is demodulated.

Embodiment 4. In the third embodiment, the configuration in which the second local oscillation signal is multiplied by M and multiplied by N is shown, but the configuration may be such that only one of M and N is multiplied. In the following, configurations (configuration 1 and configuration 2) in the case of multiplying by M and by multiplying by N will be described with reference to FIGS. 5 and 6.

[Structure 1] FIG. 5 shows a structure in which the second local oscillation signal is multiplied by M times. In FIG. 5, the frequency synthesizer circuit 27 includes a first local oscillator 13, a second local oscillator 13, and a second local oscillator 13.
A local oscillator 70 and a TCXO 5 are included, and an M multiplier circuit 25 is provided on the output side of the second local oscillator 70. The second local oscillating unit 70 is composed of a PLL having a VCO 71, a prescaler 72, a frequency dividing circuit 73, and a phase comparing circuit 74.
The local oscillation signal is output.

The second local oscillation signal is {(transmission frequency ft
-The frequency of the first local oscillation signal fL1) / M} or {(first
It has a frequency of local oscillation signal fL1−transmission frequency ft) / M} and a frequency equal to {first intermediate frequency fIF1 ± second intermediate frequency fIF2}. Therefore,
On the receiving side, the second local oscillation signal forms the third local signal (fL3) as it is, and is supplied to the second down converter 10. On the other hand, on the transmission side, the second local oscillation signal is supplied to the M multiplication circuit 25 and is multiplied by M, whereby the carrier signal (fC) is generated.

[Structure 2] FIG. 6 shows a structure in which the second local oscillation signal is multiplied by N times. In FIG. 6, the frequency synthesizer circuit 28 includes a first local oscillator 13, a second local oscillator 13, and a second local oscillator 13.
A local oscillation unit 80 and a TCXO 5 are included, and an N multiplication circuit 26 is provided on the output side of the second local oscillation unit 80. The second local oscillating unit 80 is composed of a PLL having a VCO 81, a prescaler 82, a frequency dividing circuit 83 and a phase comparing circuit 84, and the VCO 81 outputs a second local oscillating signal.

The second local oscillation signal generated by the second local oscillation unit 80 is {transmission frequency ft-frequency fL1 of first local oscillation signal} or {frequency fL1 of first local oscillation signal-transmission frequency ft. }, And {(first
The intermediate frequency fIF1 ± the second intermediate frequency fIF2) ÷ N}. Therefore, the second local oscillation signal forms the carrier signal (fC) on the transmitting side and is directly supplied to the modulation circuit 7. On the other hand, on the receiving side, the second local oscillation signal is supplied to the N multiplication circuit 26 and multiplied by N to generate the third local signal, and the second down converter 1
0 is supplied.

With the configuration as shown in FIGS. 5 and 6, the local oscillation signal (fL generated by the two local oscillation units 13 and 70 (80) is also used in the fourth embodiment.
It is possible to transmit and receive a signal based on 1, fL2). In addition, in this embodiment, in addition to the two local oscillators,
It is configured by providing either one of the M multiplication circuit or the N multiplication circuit, and the second embodiment is related to the miniaturization of the circuit.
Is also advantageous.

Embodiment 5. The first embodiment has a configuration in which the second local oscillation signal is divided by M and N by the two frequency dividing circuits 15 and 16, but this frequency dividing circuit is configured by a single variable frequency dividing circuit. can do.

FIG. 7 shows a configuration in which such a variable frequency dividing circuit 30 is provided on the output side of the second local oscillator 14.
Here, in FIG. 7, the wireless device is assumed to be a communication device such as a TDMA system (time division multiple access system). In a TDMA wireless device, transmission timing and reception timing are time-division controlled. Therefore, if the frequency division number of the variable frequency dividing circuit 30 is controlled to be switched at each time of transmission and reception, a single variable frequency dividing circuit 30
The second local oscillation signal (fL2) output from the second local oscillator 14 can be divided by M and N, respectively.

The operation of the fifth embodiment will be described below.

First, at the time of transmission, the variable frequency dividing circuit 30
Are set in the M frequency dividing circuit by the switching signal. Therefore, the second local oscillation signal is frequency-divided by the variable frequency dividing circuit 30 and supplied to the modulation circuit 7 as the carrier signal (fC) to be modulated. Then, the obtained modulated signal is mixed with the first local oscillation signal (fL1) in the up converter 8 to generate the transmission frequency signal (ft).

Next, at the time of reception, the variable frequency dividing circuit 30
It is switched to the N frequency dividing circuit by the switching signal. Therefore, the second local oscillation signal output from the second local oscillator 14 is divided by N and supplied to the second down converter 10 as the third local signal (fL3). As a result, the first IF
The signal is down converted to a second IF signal,
The IF signal is demodulated to extract the information signal.

The variable frequency dividing circuit 30 may be a variable frequency multiplying circuit. Further, depending on the frequency fL2 of the second local oscillation signal oscillated by the second local oscillation unit, either one of M division and N division or M division and N division as in the second and fourth embodiments. A configuration in which only one of the two times is performed is also applicable.

Embodiment 6. FIG. 8 shows a configuration of a radio apparatus and a configuration of a frequency synthesizer circuit when quadrature modulation such as QPSK (Quadrature Phase Shift Keying) is performed as a signal modulation method. In the case of such a quadrature modulation method, as shown in FIG. 8, two signals having a phase difference of 90 degrees from each other are generated in the M frequency dividing circuit 36 provided on the output side of the second local oscillator 14. Provide a function. The second local oscillation signal output from the second local oscillation unit 14 is divided by M by the M frequency dividing circuit 36 on the transmission side and becomes two carrier signals that are 90 degrees out of phase with each other. The two carrier signals output from the M frequency dividing circuit 36 are supplied to the modulation circuit 7, modulated by the baseband signal output from the waveform generation circuit 6, and supplied to the up converter 8. Then, it is up-converted to a predetermined transmission frequency signal (ft) and transmitted to the partner station or the like.

On the receiving side, the received quadrature-modulated predetermined frequency signal (fr) is frequency-converted into the first IF signal by the first down converter 9 as in the other embodiments, and then by the second down converter 10. , The third local signal (fL2) generated by dividing the second local oscillation signal (fL2) by N
L3) and the first IF signal are mixed and converted into a second IF signal. The second IF signal is input to the demodulation circuit 11 and demodulated.

In this embodiment, it is necessary to generate two quadrature carrier signals that are 90 degrees out of phase with each other from the second local oscillation signal and supply them to the modulation circuit 7. However, the M frequency dividing circuit 36 and the N frequency dividing circuit 16 may be configured to perform only one of the M frequency dividing and the N frequency dividing according to the frequency of the required local oscillation signal, as in the above embodiment. Further, the configuration may be such that only one of M times and N times or M times or N times is performed.

[0062]

As described above, according to the present invention, two types of frequency signals can be obtained by performing frequency division or multiplication on the second frequency signal generated by the second frequency generator. . Therefore, unlike the conventional case, it is not necessary to provide frequency generators of the required number of frequency signals, that is, the number of signals having different frequencies, and it is easy to downsize the circuit and save power, and to downsize the wireless device. The effect is high.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a frequency synthesizer circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram for explaining a frequency synthesizer circuit according to configuration 1 of embodiment 2 of the present invention.

FIG. 3 is a block diagram for explaining a frequency synthesizer circuit according to configuration 2 of embodiment 2 of the present invention.

FIG. 4 is a block diagram for explaining a frequency synthesizer circuit according to a third embodiment of the present invention.

FIG. 5 is a block diagram for explaining a frequency synthesizer circuit according to configuration 1 of embodiment 4 of the present invention.

FIG. 6 is a block diagram for explaining a frequency synthesizer circuit according to configuration 2 of embodiment 4 of the present invention.

FIG. 7 is a block diagram for explaining a frequency synthesizer circuit according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram for explaining a frequency synthesizer circuit according to a sixth embodiment of the present invention.

FIG. 9 is a block diagram for explaining a conventional frequency synthesizer circuit used in a wireless device.

[Explanation of symbols]

5 TCXO, 6 Waveform generation circuit, 7 Modulation circuit, 8
Up converter, 9 1st down converter, 10 2nd down converter, 11 Demodulation circuit, 12, 17, 1
9, 20, 27, 28, 29, 35 Frequency synthesizer circuit, 13 First local oscillator, 14, 18, 50, 6
0, 70, 80 2nd local oscillator, 15 M frequency divider,
16 N divider circuit, 25 M multiplier circuit, 26 N multiplier circuit.

Claims (14)

[Claims] 1. A frequency synthesizer circuit used in a radio apparatus for generating a transmission frequency signal based on an information signal, transmitting the transmission frequency signal, and extracting the information signal based on the reception frequency signal, the frequency synthesizer circuit comprising: And a first frequency signal generation unit and a second frequency signal generation unit, and the transmission frequency using the first frequency signal and the second frequency signal or a signal created based on the second frequency signal. A frequency synthesizer circuit, wherein a signal is generated and an information signal is extracted from the received frequency signal. 2. A frequency synthesizer circuit used in a transmission / reception wireless device for generating a transmission frequency signal based on an information signal, transmitting the transmission frequency signal and transmitting the transmission frequency signal based on the reception frequency signal, the first frequency generating section. And a second frequency generation unit, wherein the first frequency signal from the first frequency generation unit is mixed on the transmission side with a modulation signal modulated based on the information signal to generate the transmission frequency signal. At the same time as generating, at the receiving side, the received frequency signal is frequency-converted into the first intermediate frequency signal by being mixed with the received frequency signal. The signal generated based on the signal is used as the carrier signal on the transmission side and is obtained from the reception frequency signal on the reception side. Frequency synthesizer circuit, characterized by frequency converting the first intermediate frequency signal by being mixed with the first intermediate frequency signal into a second intermediate frequency signal. 3. The frequency synthesizer circuit includes an M divider that divides the second frequency signal from the second frequency generator by M, and an N divider that divides the second frequency signal by N.
And at the transmitting side, the second frequency signal divided by M is
The modulated signal is modulated as a carrier signal, and the obtained modulated signal is
The transmission frequency signal is generated by mixing the frequency signal, and at the reception side, the second frequency signal divided by N is a signal obtained by frequency-converting the reception frequency signal with the first frequency signal. The frequency synthesizer circuit according to claim 1, wherein the frequency synthesizer circuit is further mixed and frequency-converted. 4. The frequency synthesizer circuit includes an M divider that divides the second frequency signal from the second frequency generator by M, and an N divider that divides the second frequency signal by N.
The second frequency generation unit generates the second frequency signal having a frequency that is M times the frequency of the carrier signal and that has a frequency that is the first intermediate frequency ± N times the second intermediate frequency. The frequency synthesizer circuit according to claim 2. 5. The frequency synthesizer circuit includes one of an M divider and an N divider that divides the second frequency signal from the second frequency generator by M, and the transmitter side In, the M divided second frequency signal or the second frequency signal is modulated as a carrier signal, and the transmission frequency signal is generated by mixing the obtained modulated signal with the first frequency signal. The second frequency signal or the N-divided second frequency signal is further mixed with a signal obtained by frequency-converting the reception frequency signal with the first frequency signal, and frequency-converted. The frequency synthesizer circuit according to claim 1. 6. The frequency synthesizer circuit includes an M divider that divides the second frequency signal from the second frequency generator by M, and the second frequency generator includes M of the frequency of the carrier signal. 3. The frequency synthesizer circuit according to claim 2, wherein the frequency synthesizer circuit generates the second frequency signal having a frequency equal to the first intermediate frequency ± the second intermediate frequency. 7. The frequency synthesizer circuit includes an N divider that divides the second frequency signal from the second frequency generator by N, and the second frequency generator is equal to the frequency of the carrier signal. The frequency synthesizer circuit according to claim 2, wherein the second frequency signal having the frequency equal to the first intermediate frequency ± N times the second intermediate frequency is generated. 8. The frequency synthesizer circuit includes an M multiplication unit for multiplying the frequency of the second frequency signal from the second frequency generation unit by M, and a frequency of the second frequency signal by N.
By multiplying the second frequency signal, which has been multiplied by N, by the transmission side with the second frequency signal being modulated as a carrier signal, and mixing the first frequency signal with the obtained modulated signal. The transmission frequency signal is generated, and at the reception side, the second frequency signal multiplied by N is further mixed with a signal obtained by frequency-converting the reception frequency signal with the first frequency signal, thereby performing frequency conversion. The frequency synthesizer circuit according to claim 1, wherein the frequency synthesizer circuit comprises: 9. The frequency synthesizer circuit multiplies the frequency of the second frequency signal from the second frequency generator by M times and the frequency of the second frequency signal by N times.
And N times the frequency of the carrier signal.
The frequency synthesizer circuit according to claim 2, wherein the frequency synthesizer circuit generates the second frequency signal which is M times and has a frequency of the first intermediate frequency ± 1 / N times the second intermediate frequency. 10. The frequency synthesizer circuit includes either one of an M multiplication unit for multiplying the frequency of the second frequency signal from the second frequency generation unit by M or a N multiplication unit for multiplying N by N. On the transmitting side, M times the second frequency signal or the second frequency signal
A frequency signal is modulated as a carrier signal, and the transmission frequency signal is generated by mixing the obtained frequency-modulated signal with the first frequency signal. At the reception side, the second frequency signal or N times the second frequency signal is generated.
The frequency synthesizer circuit according to claim 1, wherein the frequency signal is further frequency-converted by further mixing with a signal obtained by frequency-converting the received frequency signal with the first frequency signal. 11. The frequency synthesizer circuit includes an M multiplication unit that multiplies the frequency of the second frequency signal from the second frequency generation unit by M times, and the second frequency generation unit includes the frequency of the carrier signal. 1 / of
3. The frequency synthesizer circuit according to claim 2, wherein the frequency synthesizer circuit generates the second frequency signal which is M times and has a frequency equal to the first intermediate frequency ± the second intermediate frequency. 12. The frequency synthesizer circuit includes an N multiplier for multiplying the frequency of the second frequency signal from the second frequency generator by N, and the second frequency generator includes a frequency of the carrier signal. 3. The frequency synthesizer circuit according to claim 2, wherein the frequency synthesizer circuit generates the second frequency signal having a frequency equal to the first intermediate frequency ± 1 / N times the second intermediate frequency. 13. The frequency synthesizer circuit includes a variable frequency division section or a variable frequency multiplication section capable of arbitrarily switching a frequency division value or a frequency multiplication value for the second frequency signal from the second frequency generation section. 13. The frequency synthesizer circuit according to claim 1, wherein the frequency synthesizer circuit is a frequency synthesizer circuit. 14. A signal generator that generates two frequency signals having mutually orthogonal phase components from a second frequency signal from the second frequency generator or a signal generated based on the second frequency signal. 14. The frequency synthesizer circuit according to claim 1, wherein the two frequency signals are carrier signals, and the carrier signals are modulated based on the information signals.