JP3361731B2 - Quadrature modulator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quadrature modulator used in a transmitter of a mobile terminal, and more particularly to a quadrature modulator configured so that a modulated wave signal does not contain a spurious component.

[0002]

2. Description of the Related Art As a conventional quadrature modulator in which spurious components do not appear in the vicinity of a modulated carrier signal, for example, a circuit as shown in FIG. 7 is known.

In the conventional quadrature modulator shown in FIG. 7, the oscillation frequency of the local oscillator 1 is set to 4/5 times the carrier frequency fc, and the oscillation signal of the local oscillator 1 is divided by 4 by the frequency divider 2. A modulated wave signal is obtained by generating two signals that are ⅕ times the carrier frequency and orthogonal to each other, and add and add the baseband I signal and the baseband Q signal by the quadrature modulation circuit 5 and obtain the modulated wave signal. The mixer 6 integrates the wave signal and the oscillation signal of the local oscillator to obtain a modulated wave signal whose frequency is converted to the carrier frequency.

According to such a configuration of the conventional quadrature modulator, in the vicinity of the modulated wave signal whose frequency is converted to the carrier frequency fc, for example, an integer of the frequency divider output signal for dividing the local oscillator output signal into four. Double harmonic components may appear. However, since the frequency after dividing by 4 is set to ⅕ of the carrier frequency, the 5 times higher harmonic that should occur in the closest vicinity matches the carrier frequency, and the next harmonic that occurs next is the carrier frequency. Since it is separated from the frequency by ⅕ times the carrier frequency and can be easily suppressed by a filter mounted in the subsequent stage of the modulator, apparently no spurious component appears in the vicinity of the carrier.

[0005]

However, in reality, there is a high possibility that an integer multiple harmonic component of the signal after being divided by 4 will be generated, and in particular, the 5 times higher harmonic component will match the frequency of the carrier wave, so And the carrier wave of the modulated wave signal after frequency conversion is output, which causes deterioration of modulation accuracy and becomes a problem. In order to suppress this 5 times higher harmonic, it is necessary to take measures such as providing a filter between the quadrature modulation circuit 5 and the mixer 6.

The present invention solves the above-mentioned conventional problem, in which the spurious components appearing in the vicinity of the carrier wave when the divided harmonics do not match the frequency of the carrier wave and are present in the vicinity of the carrier wave by the filter inserted at the modulator output end. It is an object to provide a quadrature modulator that can be suppressed.

[0007]

The quadrature modulator of the present invention comprises:
A first frequency divider that divides the output signal of the local oscillator by two, a phase shifter that divides the output of the first frequency divider into two signals that are orthogonal to each other, and outputs the output signal of the local oscillator. A quadrature modulation circuit for generating a modulated wave signal by integrating a second frequency divider for dividing by 3 and two orthogonal signal outputs of the phase shifter with a baseband I signal and a baseband Q signal, respectively, and adding them. And a first mixer circuit that generates a modulated wave signal having a carrier frequency component by integrating and frequency converting the output signal of the second frequency divider and the modulated wave signal output from the quadrature modulation circuit. Since the spurious component is generated at the farthest position from the carrier by selecting the oscillation frequency of the local oscillator to be 6/5 times the carrier frequency, the spurious component can be easily generated by the filter inserted in the output stage of the quadrature modulator. To It is obtained by allowing pressure.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a first frequency divider that divides a signal output from a local oscillator by 2 and a signal output from the first frequency divider. A phase shifter that distributes and outputs two orthogonal signals, a second frequency divider that divides the signal output from the local oscillator by three, and two orthogonal signals output from the phase shifter at the baseband I, respectively.
A quadrature modulation circuit that generates a modulation wave signal by integrating and adding the signal and the baseband Q signal, a modulation wave signal output from the quadrature modulation circuit, and a signal output from the second frequency divider. A first mixer for frequency-converting the modulated wave signal to a carrier frequency, and setting the oscillation frequency of the local oscillator to a frequency that is 6/5 times the carrier frequency to leak the first mixer. This is a quadrature modulator characterized in that the output spurious component is at least ⅕ times the carrier frequency away from the carrier frequency. Since the spurious component is generated at a position distant from the carrier frequency, it can be easily suppressed. Has the effect of.

According to a second aspect of the present invention, the frequency division ratio of the first frequency divider is 3 and the frequency division ratio of the second frequency divider is 2. The quadrature modulator according to claim 1 is provided, and the power consumption can be reduced as compared with the above claim 1, and the same operation as that of the above claim 1 can be achieved.

According to a third aspect of the present invention, the first frequency divider and the phase shifter are composed of a D flip-flop circuit or the like, and frequency-divided by 2 and two orthogonal signals are output. The quadrature modulator according to claim 1 is provided with a frequency divider, and the circuit can be made smaller than that of claim 1, and the same operation as that of claim 1 can be achieved.

According to a fourth aspect of the present invention, the frequency division ratio of the first frequency divider is (NM) or M, and the second frequency division ratio is M or (N-). M), and (NM)
/ N and M / N are not integral multiples of 1, and M and N are N
4. An integer having a relation of> M, and the frequency of the local oscillator is set to ((N−M) · M) / N multiplied by a carrier frequency. The above quadrature modulator has the same operation as that of claim 1.

According to a fifth aspect of the present invention, the output signal of the second frequency divider is a rectangular wave with a duty ratio of 50%. This is a modulator and has an effect of preventing even harmonic components from appearing.

According to a sixth aspect of the present invention, the oscillation frequency of the local oscillator is set to a frequency which is 6/5 times the carrier frequency, and the signal output from the local oscillator is divided by two. The modulated signal is generated by distributing and dividing the frequency-divided signal into two orthogonal signals, adding the baseband I signal and the baseband Q signal, and adding the signals, and the signal output from the local oscillator is divided into three. The frequency is divided, and the spurious component generated when leaking when the modulated wave signal obtained by frequency-converting the modulated wave signal up to the carrier frequency is obtained by integrating the modulated wave signal and the modulated wave signal. From at least 1 of the carrier frequency
This is a spurious separation / isolation control method in which the spurious component is separated by 1/5 of the carrier frequency.
It has the effect that it can be separated five times.

The invention according to claim 7 of the present invention has an information processing function having an input means, a display output means, and a data processing means, and a wireless communication function for performing data communication via an antenna. The communication function further includes a data transmission unit and a data reception unit, and the transmission unit includes a first frequency divider that divides a signal output from a local oscillator by two, and the first frequency divider. A phase shifter that divides the signal output from the frequency divider into two orthogonal signals and outputs the divided signal, a second frequency divider that divides the signal output from the local oscillator into three, and an orthogonal signal output from the phase shifter. Baseband I for each of the two signals
A quadrature modulation circuit that generates a modulation wave signal by integrating and adding the signal and the baseband Q signal, a modulation wave signal output from the quadrature modulation circuit, and a signal output from the second frequency divider. A first mixer for frequency-converting the modulated wave signal to a carrier frequency, and setting the oscillation frequency of the local oscillator to a frequency that is 6/5 times the carrier frequency to leak the first mixer. A portable terminal characterized in that it includes at least a quadrature modulator in which a spurious component to be output is separated from a carrier frequency by at least 1/5 of the carrier frequency,
Since the spurious component is generated at a position distant from the carrier frequency, the spurious component can be easily suppressed even in the mobile terminal.

According to an eighth aspect of the present invention, the phase shifter for dividing and outputting the signal output from the local oscillator into two orthogonal signals is based on the two orthogonal signals output from the phase shifter. A quadrature modulation circuit that generates a modulated wave signal by integrating and adding a band I signal and a baseband Q signal, a multiplier that doubles the signal output from the local oscillator, and a signal output from the multiplier. A frequency divider that divides the frequency by 3; a first mixer that integrates the modulated wave signal output from the quadrature modulation circuit and the signal output from the frequency divider to frequency convert the modulated wave signal to a carrier frequency;
By setting the oscillation frequency of the local oscillator to a frequency that is 3/5 times the carrier frequency, the spurious component leaking and output from the first mixer is at least 1/5 times the carrier frequency away from the carrier frequency. The quadrature modulator is characterized in that it can reduce the power consumption of the local oscillator and generate spurious components at a position distant from the carrier frequency so that they can be easily suppressed.

According to a ninth aspect of the present invention, the oscillation frequency of the local oscillator is set to 3/5 times the carrier frequency, and the signal output from the local oscillator is converted into two orthogonal signals. A modulated wave signal is generated by distributing and outputting the baseband I signal and the baseband Q signal, and adding the baseband I signal and the baseband Q signal, respectively, and at the same time, the signal output from the local oscillator is doubled, and this doubled signal is divided by three. Then, at least the spurious component, which leaks when the modulated wave signal obtained by frequency-converting the modulated wave signal up to the carrier frequency is obtained by integrating the frequency-divided signal and the modulated wave signal from the carrier frequency, This is a spurious component separation control method in which the carrier frequency is separated by ⅕ times, and the spurious component is separated by ⅕ times the carrier frequency. It has the effect that it is.

According to a tenth aspect of the present invention, there is provided an information processing function having an input means, a display output means, and a data processing means, and a wireless communication function for performing data communication via an antenna. The communication function further includes a data transmission unit and a data reception unit, wherein the transmission unit divides the signal output from the local oscillator into two orthogonal signals and outputs the phase shifter, and the phase shifter. Quadrature modulation circuit for generating a modulated wave signal by integrating and adding two orthogonal signals output from the device with a baseband I signal and a baseband Q signal respectively, and a multiplication for multiplying the signal output from the local oscillator by 2. A frequency divider, a frequency divider that divides the signal output from the multiplier into three, a modulated wave signal output from the quadrature modulation circuit and a signal output from the frequency divider, and the modulated wave signal is divided into carrier waves. A first mixer for performing frequency conversion to a number, and by setting the oscillation frequency of the local oscillator to a frequency that is 3/5 times the carrier frequency, the spurious component leaking from the first mixer and output is a carrier wave. The mobile terminal is characterized by including at least a quadrature modulator that is at least ⅕ of a carrier frequency away from the frequency, and a spurious component is generated at a position distant from the carrier frequency. The terminal also has the effect of easily suppressing spurious components.

According to an eleventh aspect of the present invention, a multiplier for multiplying the signal output from the local oscillator by two, a divider for dividing the signal output from the multiplier by three, and the divider. A phase shifter that divides the signal output from the above into two orthogonal signals and outputs, and a modulation by adding the two orthogonal signals output from the phase shifter to a baseband I signal and a baseband Q signal, respectively, and adding them. A quadrature modulation circuit that generates a wave signal, and a first mixer that integrates the modulation wave signal output from the quadrature modulation circuit and the signal output from the local oscillator to frequency convert the modulation wave signal to a carrier frequency, The oscillation frequency of the local oscillator is 3 / of the carrier frequency
The quadrature modulator is characterized in that by setting the frequency to 5 times, the spurious component leaked and output from the first mixer is at least ⅕ times the carrier frequency from the carrier frequency. The spurious component is generated at a position distant from the carrier frequency, so that the spurious component can be easily suppressed.

According to a twelfth aspect of the present invention, the oscillation frequency of the local oscillator is set to 3/5 times the carrier frequency, and the signal output from the local oscillator is doubled. The frequency-multiplied signal is divided into three, the divided signal is distributed and output to two orthogonal signals, and the baseband I signal and the baseband Q signal are respectively integrated and added to generate a modulated wave signal. A spurious component that leaks when a modulated wave signal obtained by integrating the signal output from the local oscillator and the modulated wave signal to obtain a modulated wave signal whose frequency is converted to the modulated wave signal is obtained from the carrier wave frequency. This is a spurious component separation control method in which the carrier frequency is separated by 1/5 times, and the spurious component is separated by 1/5 times the carrier frequency. It has the effect that the door can be.

According to a thirteenth aspect of the present invention, there is provided an information processing function having an input means, a display output means and a data processing means, and a wireless communication function for performing data communication through an antenna. The communication function further includes a data transmission unit and a data reception unit, wherein the transmission unit multiplies the signal output from the local oscillator by 2 and the signal output from the frequency multiplier by 3 minutes. A frequency divider that divides the frequency, a phase shifter that divides the signal output from the frequency divider into two orthogonal signals, and outputs the two orthogonal signals output from the phase shifter as a baseband I signal and a baseband signal, respectively. A quadrature modulation circuit that generates a modulated wave signal by integrating and adding the Q signal, a modulated wave signal output from the quadrature modulation circuit, and a signal output from the local oscillator to integrate the modulated wave signal with a carrier wave frequency. A first mixer for performing frequency conversion to a number, and by setting the oscillation frequency of the local oscillator to a frequency that is 3/5 times the carrier frequency, the spurious component leaking from the first mixer and output is a carrier wave. The mobile terminal is characterized by including at least a quadrature modulator that is at least ⅕ of a carrier frequency away from the frequency, and a spurious component is generated at a position distant from the carrier frequency. The terminal also has the effect of easily suppressing spurious components.

FIG. 1 shows an embodiment of the present invention.
From now on, description will be made with reference to the block diagram of FIG.

(First Embodiment) FIG. 1 is a block diagram showing the configuration of a quadrature modulator according to the first embodiment of the present invention. In FIG. 1, the oscillation frequency of the local oscillator 1 is the carrier frequency. It is set to 6/5 times fc, the output signal of the local oscillator 1 is divided by 2 by the frequency divider 2, and then two signals orthogonal to each other are generated by the phase shifter 3 composed of CR and the like, and the orthogonal modulation circuit 5 is generated. A modulated wave signal is obtained by inputting and quadrature modulating the IQ baseband signal fm. On the other hand, the output signal of the local oscillator 1 is divided by 3 by the frequency divider 4 to obtain a signal having a frequency component of 2 · fc / 5. A modulated carrier signal is generated by inputting this signal and the modulated wave signal into the mixer 6 and integrating them. Now, the harmonic component included in the output signal of the phase shifter 3 has a fundamental component of 3 · fc / 5, and therefore is an integral multiple of 6 · fc / 5,9.
.Fc / 5, ..., Each of which is quadrature-modulated by the quadrature modulation circuit 5 and outputs a modulated wave signal.

On the other hand, the harmonic component contained in the output signal of the frequency divider 4 has an integral multiple of 4 · fc / 5, 6 · fc / 5, ... Since the fundamental component is 2 · fc / 5. is there. When these signals are input to the mixer 6, the spurious components leaking from the mixer 6 and appearing in the output are separated from the carrier frequency by at least about fc / 5, so that the filter 7 inserted in the subsequent stage of the mixer 6 can easily perform it. Can be suppressed.

By the way, recently, a portable terminal having a mobile computing function is known, and the portable terminal has an information processing function including an input unit, a display output unit and a data processing unit, and data communication (through an antenna). A wireless communication function for performing voice (including voice), and the wireless communication function further includes a data transmission unit and a data reception unit, and the transmission unit has a quadrature modulator having the above-described operation. By including the above, it is possible to provide a mobile terminal with little deterioration in modulation accuracy.

(Second Embodiment) FIG. 2 is a block diagram showing the configuration of a quadrature modulator according to a second embodiment of the present invention. In FIG. 2, the oscillation frequency of the local oscillator 1 is the carrier frequency. It is set to 6/5 times fc, the output signal of the local oscillator 1 is divided by 3 by the frequency divider 2, and then two signals orthogonal to each other are generated by the phase shifter 3 composed of CR and the A modulated wave signal is obtained by inputting and quadrature modulating the IQ baseband signal fm. Here, since the frequencies of the two orthogonal signals input to the quadrature modulation circuit 5 are as low as 2 · fc / 5, low power consumption can be achieved.

On the other hand, the output signal of the local oscillator 1 is the frequency divider 4
Is divided by 2 to obtain a signal whose frequency component is 3 · fc / 5.
A modulated carrier signal is generated by inputting this signal and the modulated wave signal into the mixer 6 and integrating them.

Since the fundamental wave component of the output signal of the phase shifter 3 is 2 · fc / 5, it is an integral multiple of 4 · fc / 5, 6 · fc / 5, ... Yes, the quadrature modulation circuit 5 performs quadrature modulation and outputs a modulated wave signal.
On the other hand, the harmonic component contained in the output signal of the frequency divider 4 has a fundamental component of 3 · fc / 5, and therefore is an integral multiple of 6 · f.
c / 5, 9 · fc / 5, ...

When these signals are input to the mixer 6,
Since the spurious component leaking from the mixer 6 and appearing in the output is separated from the carrier frequency by at least about fc / 5, it can be easily suppressed by the filter 7 inserted in the subsequent stage of the mixer 6.

(Third Embodiment) FIG. 3 is a block diagram showing the configuration of a quadrature modulator according to a third embodiment of the present invention. In FIG. 3, the oscillation frequency of the local oscillator 1 is the carrier frequency. It is set to 6/5 times fc, the output signal of the local oscillator 1 is divided into two by a frequency divider 2 composed of a D flip-flop circuit, and two orthogonal signals are generated and input to the quadrature modulation circuit 5. A modulated wave signal is obtained by orthogonally modulating the IQ baseband signal fm. Here, by providing the frequency divider 2 with the function of a phase shifter, the circuit can be downsized.

On the other hand, the output signal of the local oscillator 1 is the frequency divider 4
Is divided by 3 to obtain a signal having a frequency component of 2 · fc / 5.
A modulated carrier signal is generated by inputting this signal and the modulated wave signal into the mixer 6 and integrating them.

Since the fundamental wave component of the harmonic component contained in the output signal of the phase shifter 3 is 3 · fc / 5, it is an integral multiple of 6 · fc / 5, 9 · fc / 5, ... Yes, the quadrature modulation circuit 5 performs quadrature modulation and outputs a modulated wave signal.
On the other hand, the harmonic component contained in the output signal of the frequency divider 4 has a fundamental component of 2 · fc / 5, and thus is an integral multiple of 4 · f.
c / 5, 6 · fc / 5, ...

When these signals are input to the mixer 6,
Since the spurious component leaking from the mixer 6 and appearing in the output is separated from the carrier frequency by at least about fc / 5, it can be easily suppressed by the filter 7 inserted in the subsequent stage of the mixer 6.

(Fourth Embodiment) FIG. 4 is a block diagram showing the configuration of a quadrature modulator according to a fourth embodiment of the present invention. In FIG. 4, the oscillation frequency of the local oscillator 1 is the carrier frequency. It is set to ((N−M) · M) / N times fc, and the output signal of the local oscillator 1 is divided by (N−M) or M by the frequency divider 2 to generate two orthogonal signals. , Or a frequency divider output signal is generated by a phase shifter 3 composed of CR or the like into two orthogonal signals, which are input to the orthogonal modulation circuit 5 and orthogonally modulated with the IQ baseband signal fm to obtain a modulated wave signal. .

On the other hand, the output signal of the local oscillator 1 is the frequency divider 4
The frequency component is divided by M or (NM) by
M) · fc / N or M · fc / N signal is obtained. A modulated carrier signal is generated by inputting this signal and the modulated wave signal into the mixer 6 and integrating them.

Now, when the fundamental wave component is Mfc / N, the harmonic component contained in the output signal of the frequency divider 2 or the phase shifter 3 is an integral multiple of 2Mfc / N, 3 M ・ fc / N, ...
And output a modulated wave signal that is quadrature modulated by the quadrature modulation circuit 5.

On the other hand, when the fundamental wave component contained in the output signal of the frequency divider 4 is (N−M) · fc / N, it is an integral multiple of 2 · (N−M) · fc / N. , 3 ・ (NM) ・
fc / N 2, ... When these signals are input to the mixer 6, the spurious components leaking from the mixer 6 and appearing in the output are separated from the carrier frequency by at least about fc / N. Therefore, when N is a relatively small value, It can be easily suppressed by the inserted filter 7. The frequency division ratio of the frequency divider 2 is M, and the frequency division ratio of the frequency divider 4 is (N−
The same can be considered when set to M). However, (N-
M) / N and integer multiples of M / N do not become 1, but M and N
Is an integer having a relationship of N> M.

If the output signal of the frequency divider 4 is a rectangular wave with a duty ratio of 50%, even-numbered harmonic components do not appear, so the amount of suppression of spurious components in the filter 7 can be reduced.

(Fifth Embodiment) FIG. 5 is a block diagram showing the configuration of a quadrature modulator according to a fifth embodiment of the present invention. In FIG. 5, the oscillation frequency of the local oscillator 1 is the carrier frequency. fc is set to 3/5 times, the output signal of the local oscillator 1 is generated by the phase shifter 3 into two orthogonal signals, which are input to the quadrature modulation circuit 5 and quadrature-modulated with the IQ baseband signal fm. Get the signal. Here, by setting the oscillation frequency of the local oscillator to 3/5 times the carrier frequency, it is possible to reduce the power consumption of the local oscillator.

On the other hand, the output signal of the local oscillator 1 is the multiplier 17
After being multiplied by 2, the frequency is divided by 3 by the frequency divider 2 to obtain a signal having a frequency component of 2 · fc / 5. The positions of the multiplier 17 and the frequency divider 2 may be reversed. A modulated carrier signal is generated by inputting this signal and the modulated wave signal into the mixer 6 and integrating them.

Since the fundamental wave component of the output signal of the phase shifter 3 is 3 · fc / 5, it is 6 · fc / 5, 9 · fc / 5, ... Yes, the quadrature modulation circuit 5 performs quadrature modulation and outputs a modulated wave signal.

On the other hand, the harmonic component contained in the output signal of the frequency divider 4 has an integral multiple of 4 · fc / 5, 6 · fc / 5, ... Since the fundamental component is 2 · fc / 5. is there. When these signals are input to the mixer 6, the spurious components leaking from the mixer 6 and appearing in the output are separated from the carrier frequency by at least about fc / 5, so that the filter 7 inserted in the subsequent stage of the mixer 6 can easily perform it. Can be suppressed.

By the way, recently, a portable terminal having a mobile computing function is known, and the portable terminal has an information processing function including an input means, a display output means and a data processing means, and data communication (via an antenna). A wireless communication function for performing voice (including voice), and the wireless communication function further includes a data transmission unit and a data reception unit, and the transmission unit has a quadrature modulator having the above-described operation. By including the above, it is possible to provide a mobile terminal with little deterioration in modulation accuracy.

(Sixth Embodiment) FIG. 6 is a block diagram showing the configuration of a quadrature modulator according to a sixth embodiment of the present invention. In FIG. 6, the oscillation frequency of the local oscillator 1 is the carrier frequency. The frequency is set to 3/5 times fc, the output signal of the local oscillator 1 is doubled by the multiplier 17, and then the frequency divider 2 divides it by three. The positions of the multiplier 17 and the frequency divider 2 may be reversed. This signal is generated by the phase shifter 3 into two orthogonal signals, input to the orthogonal modulation circuit 5, and orthogonally modulated with the IQ baseband signal fm to obtain a modulated wave signal. A modulated carrier signal is generated by inputting the output signal of the local oscillator 1 and the modulated wave signal into the mixer 6 and integrating them.

Since the fundamental wave component of the output signal of the phase shifter 3 is 2fc / 5, it is an integral multiple of 4fc / 5, 6fc / 5, ... Yes, the quadrature modulation circuit 5 performs quadrature modulation and outputs a modulated wave signal.

On the other hand, when the output signal of the local oscillator 1 is an ideal sine wave, no harmonic component appears. When these signals are input to the mixer 6, the spurious components leaking from the mixer 6 and appearing in the output are separated from the carrier frequency by at least about fc / 5, so that the filter 7 inserted in the subsequent stage of the mixer 6 can easily perform it. Can be suppressed.

By the way, recently, a portable terminal having a mobile computing function is known, and the portable terminal has an information processing function including an input unit, a display output unit and a data processing unit, and data communication (through an antenna). A wireless communication function for performing voice (including voice), and the wireless communication function further includes a data transmission unit and a data reception unit, and the transmission unit has a quadrature modulator having the above-described operation. By including the above, it is possible to provide a mobile terminal with little deterioration in modulation accuracy.

The quadrature modulator shown in FIGS. 1 to 6 is used as the MMI.
When converted to C, the filter 7 inserted after the mixer 6
May be built in the IC or mounted at the IC output end.

[0048]

As described above, according to the present invention, only one local oscillator can be constructed, and the modulated wave signal is input to the mixer for frequency conversion to the modulated carrier signal.
Since spurious components that are integral multiples of the signal are generated at a location away from the carrier without matching the carrier frequency, spurious components that leak from the mixer and appear at the output section are inserted inside the quadrature modulator or at the output end of the quadrature modulator. The spurious component can be easily suppressed by the used filter.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a quadrature modulator according to a first embodiment of the present invention,

FIG. 2 is a block diagram showing a configuration of a quadrature modulator according to a second embodiment of the present invention,

FIG. 3 is a block diagram showing a configuration of a quadrature modulator according to a third embodiment of the present invention,

FIG. 4 is a block diagram showing a configuration of a quadrature modulator according to a fourth embodiment of the present invention,

FIG. 5 is a block diagram showing a configuration of a quadrature modulator according to a fifth embodiment of the present invention,

FIG. 6 is a block diagram showing a configuration of a quadrature modulator according to a sixth embodiment of the present invention,

FIG. 7 is a diagram showing a configuration of a conventional quadrature modulator.

[Explanation of symbols]

1 local oscillator 2 First frequency divider 3 Phase shifter 4 Second frequency divider 5 Quadrature modulation circuit 6 mixer 7 filters 8 output stage amplifier 9 Quadrature modulator 10 Second mixer 11 Third mixer 12 adder 13 Baseband I signal input terminal 14 Baseband Q signal input terminal 15 Local signal input terminal 16 Modulation carrier signal output terminal 17 multiplier

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-137845 (JP, A) JP-A-7-303059 (JP, A) JP-A-8-223233 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H04L 27/00-27/38

Claims (13)

(57) [Claims] 1. A first frequency divider that divides a signal output from a local oscillator into two, and a phase shifter that divides the signal output from the first frequency divider into two orthogonal signals and outputs the signals. A second frequency divider that divides the signal output from the local oscillator by 3;
A quadrature modulation circuit that generates a modulation wave signal by integrating and adding two orthogonal signals output from the phase shifter to a baseband I signal and a baseband Q signal, respectively, and a modulation wave output from the quadrature modulation circuit. A first mixer that integrates the signal and the signal output from the second frequency divider to convert the frequency of the modulated wave signal to the carrier frequency, and sets the oscillation frequency of the local oscillator to 6/5 times the carrier frequency. A quadrature modulator characterized in that a spurious component leaked and output from the first mixer is set at a frequency so that the spurious component is at least ⅕ times the carrier frequency away from the carrier frequency. 2. The quadrature modulator according to claim 1, wherein the frequency division ratio of the first frequency divider is 3 and the frequency division ratio of the second frequency divider is 2. 3. The first frequency divider and the phase shifter are configured by a D flip-flop circuit or the like, and a frequency divider that divides by two and outputs two orthogonal signals is provided. The quadrature modulator according to claim 1. 4. The frequency division ratio of the first frequency divider is (N−M).
Or M, and the second division ratio is M or (N-
M), an integer multiple of (NM) / N and M / N does not become 1, and M and N are integers in a relationship of N> M,
4. The quadrature modulator according to claim 1, wherein the frequency of the local oscillator is set to ((N−M) · M) / N multiplied by the carrier frequency. 5. The output signal of the second frequency divider is a rectangular wave with a duty ratio of 50%.
5. The quadrature modulator according to claim 4. 6. An oscillation frequency of a local oscillator is set to a frequency that is 6/5 times a carrier frequency, the signal output from the local oscillator is divided by two, and the two divided signals are orthogonal to each other. To a baseband I signal and a baseband Q signal, respectively, to add and generate a modulated wave signal, and divide the signal output from the local oscillator by 3 and divide the signal by 3. And a spurious component generated when leaking when the modulated wave signal is frequency-converted to the carrier wave frequency by integrating the modulated wave signal to separate from the carrier wave frequency by at least ⅕ times the carrier wave frequency. Method for controlling spurious separation and separation. 7. An information processing function comprising an input means, a display output means and a data processing means, and a wireless communication function for performing data communication via an antenna, the wireless communication function further comprising a data transmission section. The transmitter includes a receiver, and the transmitter orthogonally crosses a signal output from the local oscillator by a first frequency divider and a signal output from the first frequency divider by two. A phase shifter that distributes and outputs signals
A second frequency divider that divides the signal output from the local oscillator by 3 and two orthogonal signals output from the phase shifter are integrated and added to a baseband I signal and a baseband Q signal, respectively. A quadrature modulation circuit that generates a modulation wave signal, a first modulation frequency signal output from the quadrature modulation circuit, and a signal output from the second frequency divider are integrated to frequency-convert the modulation wave signal to a carrier frequency. A mixer, and the oscillation frequency of the local oscillator is 6 / of the carrier frequency.
By setting the frequency to be 5 times, at least the quadrature modulator is arranged so that the spurious component leaking from the first mixer and output is separated from the carrier frequency by at least 1/5 of the carrier frequency. Characteristic mobile terminal. 8. A phase shifter for dividing and outputting a signal output from a local oscillator into two orthogonal signals, and two orthogonal signals output from the phase shifter are integrated with a baseband I signal and a baseband Q signal, respectively. A quadrature modulation circuit that generates a modulated wave signal by adding the two signals, a multiplier that doubles the signal output from the local oscillator, a frequency divider that divides the signal output from the multiplier into three, A first mixer for integrating the modulated wave signal output from the quadrature modulation circuit and the signal output from the frequency divider to convert the modulated wave signal to a carrier frequency is provided, and the oscillation frequency of the local oscillator is set to the carrier frequency. By setting the frequency to 3/5 times, the spurious component leaked from the first mixer and output is separated from the carrier frequency by at least 1/5 times the carrier frequency. Quadrature modulator. 9. The oscillation frequency of the local oscillator is set to a frequency that is 3/5 times the carrier frequency, and the signal output from the local oscillator is distributed and output to two orthogonal signals.
A modulated wave signal is generated by integrating and adding the baseband I signal and the baseband Q signal, respectively, and the signal output from the local oscillator is doubled, and this doubled signal is divided into three, Spurious components generated by leaking when the modulated wave signal is frequency-converted to the carrier wave frequency by accumulating the frequency-divided signal and the modulated wave signal, at least the carrier wave frequency from the carrier wave frequency A spurious separation / separation control method that is set to 1/5 times apart. 10. An information processing function having an input means, a display output means, and a data processing means, and a wireless communication function for performing data communication through an antenna, the wireless communication function further comprising a data transmission section. The transmitting unit includes a phase shifter that divides the signal output from the local oscillator into two orthogonal signals and outputs the two signals that are orthogonal to each other. A quadrature modulation circuit that generates a modulated wave signal by integrating and adding a baseband I signal and a baseband Q signal, a multiplier that doubles the signal output from the local oscillator, and a signal output from the multiplier A frequency divider that divides the frequency by 3 and a first mixer that integrates the modulated wave signal output from the quadrature modulation circuit and the signal output from the frequency divider to frequency convert the modulated wave signal to a carrier frequency. And the oscillation frequency of the local oscillator is set to a frequency that is 3/5 times the carrier frequency, so that the spurious component leaked from the first mixer and output is at least 1 of the carrier frequency.
A mobile terminal comprising at least a quadrature modulator arranged to be / 5 times apart. 11. A multiplier that multiplies a signal output from a local oscillator by 2, a divider that divides the signal output from the multiplier by 3, and a signal that is output from the divider is orthogonal to each other.
And a quadrature modulation circuit for generating a modulated wave signal by integrating and adding two orthogonal signals output from the phase shifter to a baseband I signal and a baseband Q signal, respectively. And a first mixer for integrating the modulated wave signal output from the quadrature modulation circuit and the signal output from the local oscillator to convert the frequency of the modulated wave signal to the carrier frequency, and the oscillation frequency of the local oscillator to the carrier wave. A quadrature modulator characterized in that the spurious component leaked and output from the first mixer is at least ⅕ times the carrier frequency by setting the frequency to 3/5 times the frequency. . 12. An oscillation frequency of a local oscillator is set to a frequency that is 3/5 times a carrier frequency, a signal output from the local oscillator is multiplied by two, and this multiplied signal is divided into three, The signal obtained by dividing the frequency by 3 is distributed and output to two orthogonal signals, and the baseband I signal and the baseband Q are respectively output.
A modulated wave signal is generated by integrating and adding the signal, and a signal output from the local oscillator and the modulated wave signal are integrated to obtain a modulated wave signal whose frequency is converted to the carrier wave frequency. A spurious separation / separation control method in which a spurious component which leaks and is generated at this time is separated from the carrier frequency by at least 1/5 of the carrier frequency. 13. An information processing function having an input means, a display output means, and a data processing means, and a wireless communication function for performing data communication via an antenna, the wireless communication function further comprising a data transmission section. The transmitter includes a receiver, the transmitter includes a multiplier for multiplying a signal output from the local oscillator by 2, a divider for dividing the signal output from the multiplier by 3, and the divider. A phase shifter for dividing and outputting the signal output from the phase shifter into two orthogonal signals, and by adding the two orthogonal signals output from the phase shifter to the baseband I signal and the baseband Q signal, respectively, and adding the signals. A quadrature modulation circuit that generates a modulation wave signal, and a first mixer that integrates the modulation wave signal output from the quadrature modulation circuit and the signal output from the local oscillator to frequency convert the modulation wave signal to a carrier frequency. And the oscillation frequency of the local oscillator is set to a frequency that is 3/5 times the carrier frequency, so that the spurious component leaked from the first mixer and output is at least 1 of the carrier frequency.
A mobile terminal comprising at least a quadrature modulator arranged to be / 5 times apart.