JP2003198260A - Frequency converter and wireless communication device using the converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frequency converter having wide dynamic range, and to provide a wireless communication device. <P>SOLUTION: A constant current source 11, a bias circuit 40, and a frequency conversion circuit 6 are provided. The bias circuit 40 has a first transistor 7, a second transistor 8, a first resistor 9, a second resistor 26 whose one end is connected to the junction of the first resistor 9 and the second transistor 8 and whose other end is grounded, and a third resistor 10 whose one end is connected to the junction. To the other end of the third resistor 10, a first input terminal RFin 2, which supplies a frequency converted signal, is connected. The frequency conversion circuit 6 is connected to the other end of the third resistor 10, and inputs a local oscillation signal supplied from a second input terminal LOin 3. By combining the frequency-converted signal and the local oscillation signal, a frequency conversion signal, that is the frequency-converted signal whose frequency is converted, is outputted to the output terminal. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency conversion device used in a radio receiving circuit and the like, and a radio communication device using the same.

[0002]

2. Description of the Related Art In a receiving circuit of a mobile phone terminal or a receiving circuit of a base station of a mobile phone, a frequency converter is used to convert a received high frequency signal into an intermediate frequency signal.

Particularly, in mobile communication such as mobile phones in recent years, a receiving system requires a wide dynamic range because a receiving electric field greatly changes depending on a distance between a base station and a mobile terminal.

FIG. 13 shows a conventional frequency converter 10 used in a receiving circuit of a mobile phone terminal or a receiving circuit of its base station.
1 is shown.

The conventional frequency converter 101 is a circuit used in a receiving circuit of a mobile phone terminal or a receiving circuit of its base station, and synthesizes a received high frequency received signal with a local oscillation signal to form an intermediate frequency signal. It is a circuit that converts and outputs.

The frequency conversion device 101 comprises a resistor 11, a bias circuit 5, a frequency conversion circuit 6, and a local oscillation signal amplification circuit 17. The bias circuit 5 is a circuit called a current mirror circuit, and is a circuit that supplies a stable bias to the frequency conversion circuit 6. The frequency conversion circuit 6 synthesizes the high frequency reception signal input from the terminal RFin2 and the local oscillation signal input from the terminal LOin3 by the bipolar transistors 15 and 16, so that the high frequency reception signal is generated by the non-linearity of the bipolar transistors 15 and 16. This is a circuit that converts the signal into an intermediate frequency signal and outputs the converted signal from the terminal IFout4 as an intermediate frequency signal.

The bias circuit 5 is composed of bipolar transistors 7 and 8, resistors 9 and 10, and capacitors 12 and 13.

The frequency conversion circuit 6 includes bipolar transistors 14, 15, 16 and inductors 18, 1
9, 20 and capacitors 21, 22, 23, 24, 25
Composed of and.

Next, such a conventional frequency converter 1 will be described.
The operation of the form 01 will be described.

The bias circuit 40 receives power supply from the terminal Vcc1 and supplies a bias to the base of the bipolar transistor 14 of the frequency conversion circuit 6. A bias is supplied to the collectors of the bipolar transistors 15 and 16 from the terminal Vcc1 via the inductors 19 and 20, respectively.

The high frequency received signal input from the terminal RFin2 passes through the DC blocking capacitor 25, is amplified by the bipolar transistor 14, and is input from the collector of the bipolar transistor 14 to the bipolar transistors 15 and 16, respectively. The local oscillation signals input from the pair of terminals LOin3 are amplified by the local oscillation signal amplifier circuit 17 and input to the bipolar transistors 15 and 16, respectively.

The bipolar transistors 15 and 16 are
A differential circuit is formed, and the bipolar transistor 14
High-frequency reception signal amplified by and local oscillation signal amplification circuit 1
The local oscillation signal output from 7 is combined. The combined signal is output from the collectors of the bipolar transistors 15 and 16, respectively.

This output signal passes through the DC blocking capacitors 23 and 24 and is output from the terminal IFout4. Since the signal output from the terminal IFout4 passes through a filter having a characteristic of reducing frequencies other than the intermediate frequency, distortion components other than the intermediate frequency are reduced, so that a signal of the intermediate frequency can be obtained.

FIG. 14 shows the operating characteristics of the frequency conversion circuit 101.

That is, the horizontal axis LO in FIG. 14 represents the gain (unit is decibel) of the local oscillation signal amplifier circuit 17. CG is the gain (unit is decibel) of the intermediate frequency signal output from the terminal IFout4 with respect to the high frequency reception signal input from the terminal RFin, and II
P3 is an index indicating the ratio of the third-order intermodulation wave component of the output intermediate frequency signal to the high frequency reception signal input as two waves, and NF is a noise figure (Noise Figure).
e).

First, CG is a local oscillation signal amplifier circuit 17
The gain LO increases up to around -30 decibels as the LO increases, but the LO becomes substantially saturated near -30 decibels, and is substantially constant even when the LO becomes larger than -30 decibels. Is taking.

IIP3 increases with the increase of LO up to the vicinity of LO exceeding -20 decibels, but has a substantially constant value from the vicinity of LO exceeding -20 decibels.

Further, NF decreases as LO increases up to around -10 decibels, takes a minimum value near LO -10 decibels, and increases after LO exceeds -10 decibels. Is increasing with.

As described above, IIP3 is IFout.
Since the degree of the third-order intermodulation distortion component of the signal output from No. 4 is represented, the larger the value of IIP3 is, the better the characteristics of the frequency conversion device 101, that is, the third order intermodulation distortion of the signal output from IFout4. It can be said that the level of ingredients is low.

As mentioned above, NF is IFout.
Since the degree of the noise component included in the signal output from No. 4 is represented, it can be said that the smaller the value of NF, the lower the noise of the frequency conversion device 101.

The frequency converter 101 is required to have low noise characteristics and a low level of third-order intermodulation distortion component.

Therefore, if the gain of the local oscillation signal amplifier circuit 17 is set to around -10 decibels, the frequency conversion device 101 has the lowest noise and the third-order intermodulation distortion component becomes maximum from FIG. That is, when the gain of the local oscillation signal amplifier circuit 17 is set near -10 decibels, the frequency conversion device 101 has the best characteristics.

[0023]

However, since the frequency conversion device has the peculiarity of converting a high frequency received signal, that is, a high frequency signal into a low frequency signal by utilizing the non-linearity of the circuit, it has a low noise characteristic. It is difficult to achieve both low distortion characteristics and low distortion characteristics, which has been a factor that narrows the dynamic range of the receiving circuit.

That is, there is a problem that a frequency converter having both a low noise characteristic and a low distortion characteristic and a wider dynamic range is required.

Further, in the conventional frequency converter 101,
If the performance of bipolar transistors etc. is the same,
It has the best characteristics when the gain of the local oscillation signal amplification circuit 17 is set near -10 decibels, but it is difficult to realize the frequency conversion device 101 having further better characteristics, that is, the bipolar transistor. If the transistors have the same performance, it is difficult to realize a frequency conversion device having both good distortion characteristics and good noise characteristics.

In consideration of the above problems, it is an object of the present invention to provide a frequency conversion device and a wireless communication device which can achieve both low noise characteristics and low distortion characteristics and have a wider dynamic range. Is.

In view of the above problems, the present invention provides a frequency conversion device and a wireless communication device in which both the distortion characteristics and the noise characteristics are better than those of the conventional one, even if the performances of the transistors are the same. The purpose is.

[0028]

In order to solve the above-mentioned problems, the first invention (corresponding to claim 1) is a constant current source for supplying a predetermined current, a bias circuit, and a frequency conversion circuit. The bias circuit includes a first amplifier circuit supplied with a current from the constant current source, a second amplifier circuit supplied with a current from the constant current source, and the first amplifier circuit.
A first resistor connected between the first amplifying circuit and the second amplifying circuit and a connection point between the first resistor and the second amplifying circuit, and the other is grounded. Has a second resistor and a third resistor, one of which is connected to the connection point, and the other of the third resistors is connected to a first input terminal for supplying a frequency-converted signal. The frequency conversion circuit is connected to the other of the third resistors, receives the local oscillation signal supplied from the second input terminal, and synthesizes the frequency-converted signal and the local oscillation signal. Thus, a frequency-converted signal, which is a signal obtained by frequency-converting the frequency-converted signal, is output to the output terminal, and each of the second input terminal and the output terminal is a pair of frequency converters.

The second invention (corresponding to claim 2)
The frequency conversion circuit has third, fourth, and fifth amplification circuits, the third amplification circuit is connected to the other of the third resistors, and the fourth amplification circuit is The third amplifier circuit is connected to one of the second input terminals, the fifth amplifier circuit is connected to the third amplifier circuit, and the second input terminal is connected to the third input circuit. Connected to the other, one of the output terminals is connected to the fourth amplifier circuit, and the other of the output terminals is connected to the fifth amplifier circuit, the fourth amplifier circuit and the fifth amplifier circuit. The amplifier circuit is the frequency conversion device according to the first aspect of the present invention forming a differential circuit.

The third invention (corresponding to claim 3)
Is the frequency conversion device according to the second aspect of the present invention, in which the third amplification circuit is a transistor, and the emitter of the third amplification circuit is grounded via an inductor.

The fourth invention (corresponding to claim 4)
Is the frequency conversion device according to the second aspect of the present invention, in which the third amplification circuit is a transistor, and the emitter of the third amplification circuit is grounded via a capacitor and an inductor connected in parallel with each other.

The fifth invention (corresponding to claim 5)
The first amplifier circuit and the third amplifier circuit are transistors, respectively, and the emitter of the first amplifier circuit and the emitter of the third amplifier circuit are grounded via resistors. It is a frequency conversion device of the second invention.

The sixth invention (corresponding to claim 6)
The bias circuit has a fourth resistor connected to one of the third resistors, the first input terminal is a pair, and one and the other of the input terminals are respectively the The frequency conversion circuit is connected to the other of the third resistors and the other of the fourth resistors, and the frequency conversion circuit includes third, fourth, fifth, sixth, seventh, and eighth amplification circuits. , The third amplifier circuit is connected to the other of the third resistors, the fourth amplifier circuit is connected to the other of the fourth resistors, and the fifth and sixth amplifier circuits are both Connected to a third amplifier circuit, respectively connected to one and the other of the second input terminals, and respectively connected to one and the other of the output terminals, and the seventh and eighth amplifier circuits are both Is connected to the fourth amplifier circuit and is connected to the other of the second input terminals. On the other hand, are connected, and are connected to one and the other of each of the output terminals, the fifth and sixth
The amplifier circuit forms a differential circuit, and includes the seventh and eighth circuits.
The amplifier circuit is the frequency conversion device according to the first aspect of the present invention forming a differential circuit.

The seventh invention (corresponding to claim 7)
The bias circuit includes a ninth amplifier circuit which is supplied with a current from the constant current source, and a fourth resistor which is connected between the first amplifier circuit and the ninth amplifier circuit. , A fifth resistor, one of which is connected to the connection point between the fourth resistor and the ninth amplifier circuit and the other of which is grounded, and one of which is connected to the connection point and the other of which is the bias circuit. A sixth resistor connected to the outside, the first input terminal is a pair, and one and the other of the input terminals are the other of the third resistor and the sixth resistor, respectively. And the frequency conversion circuit is connected to the other of the third, fourth, and
A fifth, a sixth, a seventh, and an eighth amplifier circuit, the third amplifier circuit is connected to the other of the third resistors, and the fourth amplifier circuit is connected to the sixth resistor. The fifth and sixth amplifier circuits are connected to the other, both are connected to the third amplifier circuit, and are respectively connected to one and the other of the second input terminals, and one of the output terminals, respectively. And the other, and the seventh and eighth amplifier circuits are
Both are connected to the fourth amplifier circuit, and are respectively connected to the other and one of the second input terminals, and are connected to one and the other of the output terminals, respectively.
The sixth and sixth amplifier circuits form a differential circuit, and the seventh and eighth amplifier circuits are the frequency conversion device of the first aspect of the present invention in which a differential circuit is formed.

The eighth invention (corresponding to claim 8)
Is the sixth or seventh frequency conversion device of the invention, wherein one of the first input terminals is grounded via a capacitor.

The ninth invention (corresponding to claim 9)
The sixth amplifier circuit and the fourth amplifier circuit are transistors, respectively, and the emitter of the third amplifier circuit and the emitter of the fourth amplifier circuit are grounded via an inductor. 8 is a frequency conversion device according to any one of the present inventions.

According to a tenth aspect of the present invention (corresponding to claim 10), each of the third amplifying circuit and the fourth amplifying circuit is a transistor, and an emitter of the third amplifying circuit and the fourth amplifying circuit. In the sixth to eighth aspects of the present invention, the emitter of the amplifier circuit is connected via a capacitor, and the emitter of the third amplifier circuit and the emitter of the fourth amplifier circuit are grounded via an inductor. Any one of the frequency conversion devices.

According to an eleventh aspect of the present invention (corresponding to claim 11), each of the third amplifier circuit and the fourth amplifier circuit is a transistor, and the emitter of the third amplifier circuit and the fourth amplifier circuit are the same. The emitters of the amplifier circuits are connected to one of the inductors, the other of the inductors is connected to each other, and is grounded via a resistor at the midpoint of the wiring connecting the other of the inductors. 6 to 8 is a frequency conversion device according to any one of the present invention.

According to a twelfth aspect of the present invention (corresponding to claim 12), each of the third amplifier circuit and the fourth amplifier circuit is a transistor, and the emitter of the third amplifier circuit and the fourth amplifier circuit are the same. One of the inductors is connected to the emitter of the amplifier circuit, and the other of the inductors is connected to each other, and it is grounded via the inductor at the midpoint of the wiring that connects the other of these inductors. The frequency conversion device according to any one of the sixth to eighth aspects of the present invention.

A thirteenth aspect of the present invention (corresponding to claim 13) is a local oscillation signal amplifier circuit which is connected to the second input terminal, amplifies the local oscillation signal, and outputs the amplified signal to the frequency conversion circuit. It is a frequency conversion device according to the first aspect of the present invention.

According to a fourteenth aspect of the present invention (corresponding to claim 14), the local oscillation signal amplifier circuit receives the local oscillation signal supplied from the second input terminal as a tenth aspect.
An amplifier circuit and an eleventh amplifier circuit,
The amplifier circuit and the eleventh amplifier circuit are the frequency conversion device of the thirteenth invention, which form a differential circuit.

In the fifteenth aspect of the present invention (corresponding to claim 15), the local oscillation signal amplifier circuit supplies a constant current to the tenth amplifier circuit and the eleventh amplifier circuit. It is a frequency converter according to the 14th aspect of the present invention, which is provided with a circuit.

The sixteenth aspect of the present invention (corresponding to claim 16) is the frequency conversion device according to the fourteenth or fifteenth aspect of the present invention, wherein one of the second input terminals is grounded via a capacitor. .

According to a seventeenth aspect of the present invention (corresponding to claim 17), the local oscillation signal amplifier circuit has a first resonance circuit and a second resonance circuit in which capacitors and inductors are connected in parallel with each other. , The tenth amplifier circuit and the eleventh amplifier circuit are transistors,
The base of the tenth amplifier circuit and the base of the eleventh amplifier circuit are connected to one and the other of the second input terminals, respectively, and the emitter of the tenth amplifier circuit and the first
The emitters of the first amplification circuit are connected to each other, and the constant current supply circuit is connected to the connection point of the first amplification circuit,
The collector of the 0th amplification circuit is connected to one of the first resonance circuits, and the other of the first resonance circuits receives a bias from a bias supply source, and the collector of the 11th amplification circuit. Is connected to one of the second resonance circuits, and the other of the second resonance circuits is supplied with a bias from the bias supply source, and is connected to the collector of the tenth amplifier circuit and the eleventh amplifier circuit. The collector of the amplifier circuit is the frequency conversion device according to any one of the fourteenth to sixteenth aspects of the present invention, which is connected to the frequency conversion circuit.

According to an eighteenth aspect of the present invention (corresponding to claim 18), one of the local oscillation signal amplifier circuits has the first portion.
The frequency conversion device according to the 17th aspect of the present invention, which has a resistor connected to the other of the resonant circuits and the other of the second resonant circuits, and the other of which is connected to the bias supply source.

According to a nineteenth aspect of the present invention (corresponding to claim 19), one of the local oscillation signal amplifier circuits is connected to the other of the first resonance circuit and the other of the second resonance circuits, and the other Is a frequency converter according to the seventeenth aspect of the present invention, which has a diode connected to the bias supply source.

The twentieth aspect of the present invention (corresponding to claim 20) includes a control circuit for controlling an injection level of the local oscillation signal injected into the frequency conversion circuit according to a predetermined condition. 19 is a frequency conversion device according to any one of the present inventions.

In the twenty-first aspect of the present invention (corresponding to claim 21), the predetermined condition is a signal level of the frequency conversion signal output from the frequency conversion circuit, and the control circuit includes A frequency conversion device according to a twentieth aspect of the present invention, comprising a control circuit for controlling an injection level of the local oscillation signal injected into the frequency conversion circuit according to a signal level of the frequency conversion signal output from the frequency conversion circuit. is there.

In the twenty-second aspect of the present invention (corresponding to claim 22), the control circuit decreases the injection level of the local oscillation signal when the signal level of the frequency conversion signal increases. Frequency conversion device.

The twenty-third aspect of the present invention (corresponding to claim 23) includes a detection circuit for detecting the signal level, and the distortion of the frequency conversion signal is provided between the frequency conversion circuit and the detection circuit. The frequency conversion device according to any one of the 20th to 22nd aspects of the present invention, in which a filter for reducing a component is inserted.

In the twenty-fourth aspect of the present invention (corresponding to claim 24), the control circuit reduces the gain of the local oscillation signal amplification circuit when the signal level of the frequency conversion signal increases. The frequency conversion device according to any one of the present inventions.

In the twenty-fifth aspect of the present invention (corresponding to claim 25), lowering the gain of the local oscillation signal amplifier circuit means reducing the current of the local oscillation signal amplifier circuit. It is a frequency conversion device of the present invention.

In the twenty-sixth aspect of the present invention (corresponding to claim 26), reducing the gain of the local oscillation signal amplifier circuit means reducing the current of the local oscillation signal amplifier circuit. It is a frequency conversion device of the present invention.

In the twenty-seventh aspect of the present invention (corresponding to claim 27), the predetermined condition is a signal level of the frequency-converted signal injected into the frequency conversion circuit, and the control circuit includes: A second changing the injection level of the local oscillation signal according to the signal level of the frequency converted signal;
0 frequency converter of the present invention.

In the twenty-eighth aspect of the present invention (corresponding to claim 28), the control circuit decreases the signal level of the frequency converted signal when the signal level of the frequency converted signal increases. It is a frequency conversion device of the present invention.

In the twenty-ninth aspect of the present invention (corresponding to claim 29), reducing the signal level means reducing the gain of the local oscillation signal amplifying circuit. It is a device.

In the thirtieth invention (corresponding to claim 30), reducing the signal level means reducing the current of the local oscillation signal amplifying circuit. The frequency conversion according to the twenty-ninth invention. It is a device.

According to the 31st aspect of the present invention (corresponding to claim 31), reducing the signal level means reducing the voltage of the local oscillation signal amplifier circuit. It is a device.

The 32nd aspect of the present invention (corresponding to claim 32) is provided with a control circuit for decreasing the current output to the constant current supply circuit when the signal level of the frequency conversion signal is increased. The supply circuits are the twelfth and first
3rd and 14th amplifier circuits, and 7th, 8th, 9th, 1st
0th and 11th resistors, and the 12th, 13th, and
And the 14th amplifier circuit is a transistor, respectively, and a 7th resistor is connected between the base of the 12th amplifier circuit and the emitter of the 14th amplifier circuit,
An eighth resistor is connected between the base of the thirteenth amplifier circuit and the emitter of the fourteenth amplifier circuit, and the twelfth amplifier circuit emitter and the thirteenth amplifier circuit emitter are: The ninth resistor and the tenth resistor, respectively.
Is grounded via a resistance of the fourteenth amplification circuit, a base and a collector of the fourteenth amplification circuit are connected through the eleventh resistance, and a collector of the fourteenth amplification circuit is connected to a collector of the control circuit. The collector of the thirteenth amplifier circuit and the base of the fourteenth amplifier circuit are connected to the output, and the collector of the twelfth amplifier circuit is connected to the tenth and eleventh amplifiers. The frequency conversion device according to any one of the fifteenth to nineteenth aspects of the present invention, which is connected to a circuit.

A thirty-third aspect of the present invention (corresponding to claim 33) is provided with a control circuit for decreasing the output voltage when the signal level of the frequency conversion signal increases, and the local oscillation signal amplification circuit has an emitter. The constant current supply circuit includes a transistor connected to the other of the first resonance circuit and the other of the second resonance circuits, the collector of which is connected to the bias supply source, and the base of which is connected to the output of the control circuit. The circuit has twelfth, thirteenth, and fourteenth amplifier circuits, and seventh, eighth, ninth, tenth, and eleventh resistors,
The twelfth, thirteenth, and fourteenth amplifier circuits are each transistors, and a seventh resistor is connected between the base of the twelfth amplifier circuit and the emitter of the fourteenth amplifier circuit. An eighth resistor is connected between the base of the thirteenth amplifier circuit and the emitter of the fourteenth amplifier circuit, and the twelfth amplifier circuit emitter and the thirteenth amplifier circuit emitter are connected to each other. , The base and collector of the fourteenth amplifier circuit are connected to the first resistor and the first resistor, respectively, and are grounded via the ninth resistor and the tenth resistor, respectively.
Connected via the first resistor, the collector of the fourteenth amplifier circuit is connected to the bias supply source, and the collector of the thirteenth amplifier circuit and the base of the fourteenth amplifier circuit are connected. The collector of the twelfth amplifier circuit is connected, and is the frequency converter according to any one of the seventeenth to nineteenth aspects of the present invention, which is connected to the tenth and eleventh amplifier circuits.

The 34th aspect of the present invention (corresponding to claim 34) includes a receiving circuit for receiving a received signal, and the frequency converting device according to any one of the first to 33th aspects of the present invention is used for the receiving circuit. Wireless communication device.

[0062]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the first embodiment will be described.

FIG. 1 shows a frequency converter 8 according to this embodiment.
1 is shown. The frequency conversion device 81 of the present embodiment is a circuit used for a receiving circuit of a mobile phone terminal or a receiving circuit of its base station, and synthesizes a received high frequency received signal with a local oscillation signal to form an intermediate frequency signal. It is a circuit that converts and outputs.

The frequency conversion device 81 is composed of the resistor 11, the bias circuit 40, the frequency conversion circuit 6, and the local oscillation signal amplification circuit 17. The bias circuit 5 is a circuit called a current mirror circuit, and is a circuit that supplies a stable bias to the frequency conversion circuit 6. The frequency conversion circuit 6 synthesizes the high frequency reception signal input from the terminal RFin2 and the local oscillation signal input from the terminal LOin3 by the bipolar transistors 15 and 16, so that the high frequency reception signal is generated by the non-linearity of the bipolar transistors 15 and 16. This is a circuit that converts the signal into an intermediate frequency signal and outputs the converted signal from the terminal IFout4 as an intermediate frequency signal.

The bias circuit 40 includes bipolar transistors 7 and 8, resistors 9, 10 and 26, and a capacitor 13.
Composed of and.

Further, the frequency conversion circuit 6 includes bipolar transistors 14, 15, 16 and inductors 18, 1
9, 20 and capacitors 21, 22, 23, 24, 25
Composed of and.

In addition, the local oscillation signal amplification circuit 17 showing the configuration of the local oscillation signal amplification circuit 17 in FIG. 2 includes bipolar transistors 31, 32, a diode 37, capacitors 38, 29, 33, 35, an inductor 33, And 35.

That is, the frequency conversion circuit 81 of this embodiment is the same as the capacitor 12 of the conventional frequency conversion circuit 101.
Is replaced with a resistor 26. The characteristics of the frequency conversion device could be improved by replacing the capacitor 12 with the resistor 26, which will be described later.

First, the bias circuit 40 will be described. That is, the terminal Vcc1 which is the bias power source,
One of the resistors 11 for supplying a constant current is connected, the other of the resistors 11 is connected to the collector of the bipolar transistor 7 and the base of the bipolar transistor 8, and the collector of the bipolar transistor 8 has a terminal V.
It is connected to cc1. A capacitor 13 is connected between the emitter and collector of the bipolar transistor 7, the emitter of the bipolar transistor 7 is grounded, and a resistor 9 is provided between the base of the bipolar transistor 7 and the emitter of the bipolar transistor 8. It is connected. One of the resistors 26 and 10 is connected to the connection point between the emitter of the bipolar transistor 8 and the resistor 9, and the other of the resistors 26 is grounded.

Next, the frequency conversion circuit 6 will be described. That is, the base of the bipolar transistor 14 is connected to the other of the resistors 10 and the DC blocking capacitor 2 is connected to the terminal RFin2 that supplies a high frequency reception signal.
It is connected via 5. Bipolar transistor 1
The emitter of 4 is grounded via an inductor 18, and the collector of the bipolar transistor 14 is connected to the emitters of the bipolar transistors 15 and 16, respectively.

The base of the bipolar transistor 15 and the base of the bipolar transistor 16 are a pair of terminals LO.
It is connected to each output of the local oscillation signal amplifier circuit 17 which amplifies the local oscillation signal supplied from in. The collectors of the bipolar transistors 15 and 16 are respectively connected to one and the other of the pair of terminals IFout4 that output a signal of an intermediate frequency through the DC blocking capacitor 23 and the DC blocking capacitor 24, respectively. At the same time, it is connected to one of the inductor 19 and one of the inductor 20, respectively, and further connected to one of the capacitor 21 and one of the capacitor 22. Also, the other of the inductor 19 and the inductor 2
The other of 0 is connected to the terminal Vcc1. The other side of the capacitor 21 and the other side of the capacitor 22 are grounded.

Further, the local oscillation signal amplifier circuit 17 will be described. That is, the bases of the bipolar transistors 31 and 32 are connected to the pair of terminals LOin3,
The capacitors are connected via DC blocking capacitors 38 and 39, and are also connected to a bias circuit 29 for the local oscillation signal amplifier circuit 17, respectively. The emitters of the bipolar transistors 31 and 32 are both connected to the constant current source 30. Further, the collectors of the bipolar transistors 31 and 32 are respectively connected to the terminal LOout2.
8 is connected to one side and the other side. A pair of terminals LOo
One and the other of the ut 28 are connected to the base of the bipolar transistor 15 and the base of the bipolar transistor 16 of FIG. 1, respectively. Further, the collectors of the bipolar transistors 31 and 32 are respectively connected to one of the resonance circuits in which the capacitor 33 and the inductor 34 are connected in parallel and one of the resonance circuits in which the capacitor 35 and the inductor 26 are connected in parallel.

Then, the capacitor 33 and the inductor 3
The other of the circuits in which 4 is connected in parallel and the other of the circuits in which the capacitor 35 and the inductor 36 are connected in parallel are connected to one of the diodes 37. The other side of the diode 37 is connected to the terminal Vcc27.

Next, the operation of this embodiment will be described.

The bias circuit 40 receives power supply from the terminal Vcc1 and supplies a bias to the base of the bipolar transistor 14 of the frequency conversion circuit 6. A bias is supplied to the collectors of the bipolar transistors 15 and 16 from the terminal Vcc1 via the inductors 19 and 20, respectively.

The high frequency reception signal input from the terminal RFin2 passes through the DC blocking capacitor 25, is input to the base of the bipolar transistor 14, is amplified by the bipolar transistor 14, and is amplified by the bipolar transistor 1.
4 collectors of bipolar transistors 15 and 16
Are input respectively. Further, since the emitter of the bipolar transistor 14 is grounded via the inductor 18, good noise characteristics and good distortion characteristics can be obtained.

Local oscillation signals input from the pair of terminals LOin3 are amplified by the local oscillation signal amplifier circuit 17, respectively.

That is, in FIG. 2, a pair of terminals LO
The local oscillation signal input from in3 is input to the base of the bipolar transistor 31 and the base of the bipolar transistor 32, respectively, amplified by the bipolar transistor 31 and the bipolar transistor 32, and output from each collector. The current of the constant current source 30 and the bias voltage supplied by the Vcc 27 are adjusted so that the frequency conversion circuit 6 has good characteristics.

The local oscillation signals output from the pair of terminals LOout 28 are input to the bipolar transistors 15 and 16 in FIG. 1, respectively. The bipolar transistors 15 and 16 form a differential circuit, and combine the high frequency reception signal amplified by the bipolar transistor 14 and the local oscillation signal output from the local oscillation signal amplification circuit 17. The combined signal is output from the collectors of the bipolar transistors 15 and 16, respectively.

Due to the non-linearity of the bipolar transistors 15 and 16, this output signal contains an intermediate frequency signal having a frequency difference between the frequency of the high frequency reception signal and the frequency of the local oscillation signal. Further, since the bipolar transistors 15 and 16 form a differential circuit as described above, the signals of the fundamental wave frequency such as the signal of the frequency of the high frequency reception signal are canceled with each other.

This output signal passes through the DC blocking capacitors 23 and 24 and is output from the terminal IFout4. Since the signal output from the terminal IFout4 passes through a filter having a characteristic of reducing frequencies other than the intermediate frequency, distortion components other than the intermediate frequency are reduced, so that a signal of the intermediate frequency can be obtained.

FIG. 3 shows the operating characteristics of the frequency conversion circuit 81.

In the frequency converter 81 of this embodiment,
A resistor 26 is used in place of the capacitor 12 of the conventional frequency converter 101. By doing so, FIG.
Excellent operating characteristics such as That is, the horizontal axis LO of FIG. 3 represents the gain (unit is decibel) of the local oscillation signal amplifier circuit 17. CG is a terminal IFout
4 is the gain (unit is decibel) of the intermediate frequency signal output from the terminal 4 with respect to the high frequency reception signal input from the terminal RFin, and IIP3 is the third-order intermodulation distortion component of all the signals output from the terminal IFout4. The ratio, that is, an index indicating the ratio of the signal of the intermediate frequency, and NF is a noise figure.

First, CG is a local oscillation signal amplifier circuit 17
The gain LO increases up to around -30 decibels as the LO increases, but the LO becomes substantially saturated near -30 decibels, and is substantially constant even when the LO becomes larger than -30 decibels. Is taking.

The IIP3 increases as LO increases up to −33 decibels, reaches its maximum at −33 decibels, and starts decreasing after LO exceeds −33 decibels.

Further, NF decreases as LO increases up to around LO-10 decibels, takes a minimum value near LO-10 decibels, and increases after LO exceeds -10 decibels. Is increasing with.

As described above, IIP3 is IFout.
Since the degree of the third-order intermodulation distortion component of the signal output from No. 4 is represented, the larger the value of IIP3 is, the better the characteristics of the frequency conversion device 101, that is, the third order intermodulation distortion of the signal output from IFout4. It can be said that the level of ingredients is low. It can be said that, of the signals output from IFout4, the signal level of the intermediate frequency signal is high.

As described above, NF is IFout.
Since the degree of the noise component included in the signal output from No. 4 is represented, it can be said that the smaller the value of NF, the lower the noise of the frequency conversion device 101.

Next, the operating characteristics of FIG. 3 will be described in comparison with the operating characteristics of the conventional frequency converter 101 of FIG.

In the operation characteristic of FIG. 3, IIP3 is L
When O is -33 dB, the maximum value is 10 dB.
However, in the operation characteristics of FIG. 14, IIP3 has a value of about 6 decibels at the maximum. That is, the maximum value of IIP3 in this embodiment is larger than that in the conventional one.

Further, the difference between LO and NF is about 1 decibel when LO takes a value of -33 decibel in FIG. Further, even if the LO is in the range of -20 dB to 0 dB, the difference is 2 dB or more. However, the difference between LO and NF is −10 in LO in FIG.
The maximum is in the case of decibel, and in this case, it is about 2 decibel. As described above, the inventor replaces the capacitor 12 of FIG. 13 with the resistor 26 as shown in FIG.
It has been discovered that far superior characteristics can be realized.

As described in the prior art, the frequency converters 101 and 81 are required to have low noise characteristics and low third-order intermodulation distortion components.

Therefore, the frequency conversion device 8 of the present embodiment
If the LO is set to -33 decibels in 1, then II
It is possible to realize a frequency conversion device in which P3 is 10 decibels. This is the conventional frequency converter 101, and L
The value of IIP3 is much higher than if O was set to -10 decibels. When LO is -33 dB, N
The value of F is also slightly larger than that of the conventional one. However, since the distortion characteristic is sufficiently good, the signal level of the intermediate frequency signal can be made sufficiently high, so that the influence of noise can be canceled.

As described above, the frequency converter 81 of the present embodiment uses the resistor 26 instead of the capacitor 12, so that the noise characteristic is about the same as that of the conventional one.
It was possible to improve the distortion characteristics over the conventional one. Therefore, it can be said that the frequency conversion device 81 of the present embodiment has better characteristics than the conventional frequency conversion device 101.

In order to set LO to -10 decibels, the constant current source 3 of the local oscillation signal amplifier circuit 17 of FIG.
The amount of current of 0 may be adjusted, or the voltage between the emitter and collector of each of the bipolar transistors 31 and 32 may be adjusted. The LO adjustment method will be described later.

As described above, the frequency converter 81 of the present embodiment replaces the capacitor 12 of FIG. 13 with the resistor 26 as shown in FIG. Much better characteristics were achieved.

FIG. 12 shows CG, IIP3, and NF obtained by simulation. That is, FIG.
Are CG, IIP3 by simulation by changing the capacitance values of the capacitors 33 and 35 of the local oscillation signal amplifier circuit 17 of the frequency conversion device 81 of the present embodiment and the transistor size of each bipolar transistor, and
This is the NF. Thus, in the simulation, the peak position of IIP3 and the bottom position of NF could be matched by adjusting the capacitance values of the capacitors 33 and 35 and the transistor size of each bipolar transistor. Therefore, by setting LO at the positions corresponding to the above-mentioned peak value and bottom position, it can be expected to realize a frequency conversion device having good distortion characteristics and noise characteristics.

In this embodiment, the capacitor 1 is placed between the collector and the emitter of the bipolar transistor 7.
3 has been connected, the capacitor 13
Does not have to be connected.

Further, in this embodiment, the emitter of the bipolar transistor 7 and the bipolar transistor 8 are
Although it has been described that the resistor 11 is connected to the base of, the constant current source may be connected instead of the resistor 11.

Furthermore, in the present embodiment, the bipolar transistor 8 and the terminal Vcc1 have been described as being directly connected, but the present invention is not limited to this, and the bipolar transistor 8 and the terminal Vcc1 may be connected to other elements such as resistors and choke coils. It may be connected via the element.

Furthermore, in the present embodiment, the description has been made assuming that the inductor 18 is connected to the emitter of the bipolar transistor 14, but the present invention is not limited to this, and distortion characteristics and noise characteristics are somewhat deteriorated. The emitter may be directly grounded.

Further, in the present embodiment, the description has been made assuming that the inductor 18 is connected to the emitter of the bipolar transistor 14, but not limited to this, the emitter of the bipolar transistor 14 is connected in parallel with the inductor and the capacitor. It may be grounded via a resonant circuit. By doing so, both the distortion characteristic and the noise characteristic are improved.

Further, in the present embodiment, the emitter of bipolar transistor 7 may be grounded via a resistor, and the emitter of bipolar transistor 14 may be grounded via a resistor instead of inductor 18. By doing so, it is possible to further reduce the variation in the current flowing in the circuit due to the variation in the characteristics of the bipolar transistor.

Further, the terminal LOin39 of the present embodiment.
However, the present invention is not limited to this, and one of the terminals LOin39 may be grounded via a capacitor.

Further, the bipolar transistors 31 and 32 of the local oscillation signal amplifier circuit 17 of the present embodiment include a circuit in which a capacitor 33 and an inductor 34 are connected in parallel and a circuit in which a capacitor 35 and an inductor 36 are connected in parallel. Although it has been described that they are connected to the diodes via the respective circuits, they may be directly connected to the diode 37 without using these circuits. Further, the emitters of the bipolar transistors 31 and 32 may be directly connected to the terminal Vcc27.

Further, a resistor may be used instead of the diode 37.

The resistor 11 of the present embodiment is an example of the constant current source of the present invention.

(Second Embodiment) Next, a second embodiment will be described.

FIG. 4 shows a circuit diagram of the frequency conversion device 82 of the second embodiment.

The frequency conversion device 82 of the present embodiment is composed of the resistor 11, the bias circuit 43, the frequency conversion circuit 44, and the local oscillation signal amplification circuit 17.

That is, the frequency conversion circuit 82 of the present embodiment has the terminal RFin2 of the first embodiment replaced with a pair of differential type terminals RFin42.

Unlike the bias circuit 40 of the first embodiment, one of the resistors 41 of the bias circuit 43 is connected to the emitter of the bipolar transistor 8. Other than that, it is the same as the bias circuit 40 of the first embodiment.

Further, the frequency conversion circuit 44 includes bipolar transistors 14a, 14b, 15a, 15b, 16
a, 16b, the resistor 46, and the capacitors 25a, 25
b, 21, 22, 23, 24 and inductors 18a, 1
8b.

Bipolar transistors 14a and 14b
Is a differential circuit of the bipolar transistor 14 of the first embodiment.
5a and 15b are the bipolar transistor 15 of the first embodiment in a differential circuit, and the bipolar transistor 16 is the bipolar transistor 16 of the first embodiment in a differential circuit.

Bipolar transistors 14a and 14b
Is connected to the other side of the resistor 10 and the other side of the resistor 41, and is connected to one side and the other side of the pair of terminals RFin42 of the capacitor 25a.
And 25b. The emitters of the bipolar transistors 14a and 14b are connected to one of the inductors 18a and 18b, respectively, and the other of the inductors 18a and 18b is grounded via a resistor 49.

Bipolar transistors 15a and 15b
Each of the emitters is connected to the collector of the bipolar transistor 14a, and each emitter of the bipolar transistors 16a and 16b is connected to the collector of the bipolar transistor 14b.

Also, one and the other inputs of the local oscillation signal amplifier circuit 17 are connected to one and the other terminals of the pair of terminals LOin3, respectively. Bipolar transistor 1
The bases of 5a, 15b, 16a, and 16b are one of the outputs of the local oscillation signal amplification circuit 17,
It is connected to the other of the outputs, the other of the outputs, and one of the outputs. Bipolar transistors 15a, 1
The collectors of 5b, 16a, and 16b have capacitors 23, 24, and 2 respectively.
3 and the capacitor 24. Other than this, it is the same as the first embodiment.

Next, focusing on the difference between the operation of the present embodiment and that of the first embodiment, in the frequency conversion device 82 of the present embodiment, the terminal RF42 is a differential type terminal, Since the high frequency reception signal input from the terminal RF42 is input to the differential type circuit, the fundamental wave of the local oscillation signal is canceled in addition to the fundamental wave of the high frequency reception signal. Therefore, the intermediate frequency component can be made stronger than that of the frequency conversion device 81 of the first embodiment. Therefore, the first
It has better characteristics than the frequency converter 81 of the embodiment.

In addition, the inductor 18a and the inductor 1
Virtual grounding is realized by connecting with 8b.
Since one of the resistors 46 is connected to the midpoint of the inductors 18a and 18b and the other is grounded, it is possible to suppress deterioration of the characteristics of the frequency conversion device 82 due to variations in characteristics of the bipolar transistors 18a and 18b.

Incidentally, the pair of terminals RFin of the present embodiment.
One of 2 may be grounded via a capacitor. By doing so, it is possible to directly connect to an unbalanced circuit without using a balun.

Furthermore, the inductor 18a according to the present embodiment.
Although the inductor 18b and the inductor 18b have been described as being grounded via the resistor 46, they may be grounded without the resistor 46.

Furthermore, the bipolar transistors 14a and 14b of this embodiment may be connected by capacitors.

Furthermore, virtual grounding can be performed by an inductor instead of the resistor 46 of this embodiment.

Further, it goes without saying that the modifications described in the first embodiment can be similarly applied to the second embodiment.

(Third Embodiment) Next, a third embodiment will be described.

FIG. 5 shows a circuit diagram of the frequency conversion device 83 of the third embodiment.

The frequency conversion device 83 of this embodiment is composed of the resistor 11, the bias circuit 47, the frequency conversion circuit 44, and the local oscillation signal amplification circuit 17.

That is, the frequency conversion circuit 83 of the present embodiment is similar to the second embodiment except that the terminal RFin2 of the first embodiment is replaced with a pair of differential type terminals RFin42. is there.

The bias circuit 47 is obtained by replacing the bipolar transistor 8 of the bias circuit 40 of the second embodiment with differential bipolar transistors 8a and 8b.

That is, the bias circuit 47 includes bipolar transistors 7, 8a and 8b and resistors 9a, 9b and 1b.
0a, 10b, 26a, 26b, 45 and the capacitor 1
It consists of 3.

The emitter of the bipolar transistor 7 is grounded through the resistor 45, the capacitor 13 is connected between the emitter and the collector, and the collector is connected to the resistor 11 and the bipolar transistor. It is also connected to the base of 8a and the base of the bipolar transistor 8b. The base of the bipolar transistor 7 is connected to one of the resistors 9a and 9b.

The other of the resistors 9a is connected to the emitter of the bipolar transistor 8a, and the other of the resistors 9b is connected to the emitter of the bipolar transistor 8b.
A resistor 26a and a resistor 10a are connected to a connection point between the bipolar transistor 8a and the resistor 9a,
A resistor 26b and a resistor 10b are connected to a connection point between the bipolar transistor 8b and the resistor 9b.

The base of the bipolar transistor 14a of the frequency conversion circuit 44 is connected to the resistor 10a, and the base of the bipolar transistor 14b is connected to the resistor 10b. Other than that, the description is omitted because it is the same as the second embodiment.

Next, the operation of this embodiment will be described focusing on the difference from the first embodiment.

In the frequency conversion device 82 of this embodiment,
Since the terminal RF42 is a differential terminal and the high frequency reception signal input from the terminal RF42 is input to the differential circuit, the fundamental wave of the local oscillation signal is canceled in addition to the fundamental wave of the high frequency reception signal. Therefore, the second-order distortion can be made stronger than that of the frequency converter 81 of the first embodiment. Therefore, it has better characteristics than the frequency conversion device 81 of the first embodiment.

In addition, the inductor 18a and the inductor 1
Similar to the second embodiment, the virtual grounding is realized by connecting with 8b.

A resistor 45 is provided between the bipolar transistor 7 and the ground, and the inductors 18a and 18a
By providing the resistor 46 between 8b and the ground, it is possible to suppress deterioration of the characteristics of the frequency conversion device 82 due to variations in the characteristics of the bipolar transistor.

It goes without saying that the modifications described in the above embodiments can be applied to the third embodiment.

(Fourth Embodiment) Next, a fourth embodiment will be described.

FIG. 6 shows a block diagram of the frequency conversion device 84 of the fourth embodiment.

The frequency conversion device 84 of this embodiment is composed of a frequency conversion circuit 48, a filter 50, a received electric field strength recognition section 51, and a local oscillation signal amplification circuit 49.

The frequency conversion circuit 48 is assumed to be the frequency conversion circuit 6 and the bias circuit 40 of the first embodiment. The frequency conversion circuit 48 of the present embodiment is not limited to this, and may be the frequency conversion circuit and the bias circuit of the second embodiment or the third embodiment.

The filter 50 is a filter that reduces signals of frequencies other than the intermediate frequency and passes signals of the intermediate frequency.

The received electric field strength recognizing section 51 includes a filter 50.
It is a circuit that controls the gain of the local oscillation signal amplifier circuit 49 according to the signal level of the intermediate frequency signal output from.

FIG. 7 shows a circuit diagram of the local oscillation signal amplifier circuit 49. Note that, in FIG. 7, as the reception electric field strength recognition unit 51, the reception electric field strength recognition unit 51a that controls the gain by controlling the current of the local oscillation signal amplification circuit 71 is used.

The local oscillation signal amplifier circuit 49 includes bipolar transistors 56, 57, 63, 64 and 65, a diode 58, resistors 66, 67, 68, 69 and 70, capacitors 59, 61, 72 and 73, and Inductor 60,
And 62.

Of the local oscillation signal amplifier circuit 49, bipolar transistors 63, 64 and 65 and resistors 66 and 6 are used.
A circuit portion constituted by 7, 68, 69 and 70 corresponds to the constant current source 30 of FIG. 2 in the first embodiment.

The bases of the bipolar transistors 56 and 57 are connected to one of the capacitors 72 and 73 and to the bias circuit 55. The other side of the capacitor 72 and the other side of the capacitor 73 are respectively connected to the pair of terminals LOin3 in the above-described embodiment. The collector of each of the bipolar transistors 56 and 57 is a capacitor 59.
And the inductor 60 are connected to one of the resonance circuits connected in parallel, and the capacitor 61 and the inductor 62 are connected to one of the resonance circuits connected in parallel, and are connected to the frequency conversion circuit 48, respectively. The other of these resonance circuits is connected to one of the diodes 58, and the other of the diodes 58 is connected to the bias power supply Vc.
It is connected to c74.

Further, the bipolar transistors 56 and 5
Each emitter of 7 is a bipolar transistor 6
It is connected to 3 collectors. The respective emitters of the bipolar transistors 63 and 65 are grounded via the resistors 66 and 69, respectively.

A resistor 6 is provided between the base of the bipolar transistor 66 and the emitter of the bipolar transistor 64.
7 is connected, and a resistor 68 is connected between the bipolar transistor 65 and the bipolar transistor 64. The collector of the bipolar transistor 65 and the base of the bipolar transistor 64 are connected,
One of the resistors 70 is connected to the base of the bipolar transistor 64, and the other of the resistors 70 is connected to the collector of the bipolar transistor 64. The collector of the bipolar transistor 64 is connected to the reception field strength recognition unit 51a.

Next, the operation of this embodiment will be described.

The received electric field intensity recognition section 51a detects the signal level of the intermediate frequency signal output from the frequency conversion circuit 48 and passed through the filter 50.

The reception electric field strength recognition section 51a includes a filter 5
When it is detected that the signal level of the intermediate frequency signal output from 0 becomes higher than a predetermined signal level, the current output to the collector of the bipolar transistor 64 of the local oscillation signal amplification circuit 49 is reduced. In addition, when the reception electric field intensity recognition unit 51a detects that the signal level of the intermediate frequency signal output from the filter 50 becomes lower than the predetermined signal level, the reception electric field intensity recognition unit 51a increases the current output to the collector of the bipolar transistor 64. To do. As described above, when the signal level of the signal of the intermediate frequency output from the filter 50 becomes stronger than the predetermined signal level, the reception electric field strength detection unit 51a reduces the output current thereof, and the signal level of the signal of the intermediate frequency becomes the predetermined level. When it becomes weaker than the signal level of, the output current is increased. As described above, the output current is switched between two stages depending on whether the signal level of the intermediate frequency signal is higher or lower than the predetermined signal level, while the current flowing between the resistor 70 and the collector of the bipolar transistor 65 and the bipolar current. It is proportional to the current flowing through the collector side of the transistor 63. Therefore, the current output from the reception electric field intensity recognition unit 51a is proportional to the currents on the emitter side of the bipolar transistors 50 and 57. Therefore, when the output current of the reception field strength recognition unit 51a increases, the gain of the local oscillation signal amplification circuit 49 also increases, and when the output current of the reception field strength recognition unit 51a decreases, the gain of the local oscillation signal amplification circuit 49 also decreases. Will be done.

Generally, when the signal level of the high frequency received signal received from the antenna (not shown) is strong, the signal level of the signal of this intermediate frequency also becomes strong accordingly. Further, when the signal level of the high frequency reception signal is weak, the signal level of the intermediate frequency also weakens accordingly.

Therefore, the reception electric field strength recognizing section 51a performs the above-mentioned operation to control the gain of the local oscillation signal amplifying circuit 49. As a result, when the signal level of the high frequency reception signal is strong, the frequency converting circuit When the signal level of the local oscillation signal input to 48 is lowered and the signal level of the high frequency reception signal is weak, the frequency conversion circuit 4
The signal level of the local oscillation signal input to 8 is raised.

Specifically, when the signal level of the high frequency received signal is weak, that is, when the signal level of the intermediate frequency is weaker than the above predetermined signal level, LO in FIG.
A local oscillation signal near 10 decibels, that is, a local oscillation signal that minimizes NF is input to the frequency conversion circuit 48. On the other hand, when the signal level of the high-frequency reception signal is strong, that is, when the signal level of the intermediate frequency is higher than the above-mentioned predetermined signal level, in FIG. Such a local oscillation signal is input to the frequency conversion circuit 48.

Therefore, when the signal level of the high frequency received signal is weak, the frequency conversion device 48 has a characteristic of low noise, so that the influence of noise can be avoided, and at this time, CG is the maximum, that is, frequency conversion. The gain of the intermediate frequency signal output from the circuit 48 with respect to the high frequency reception signal is maximized.

On the other hand, when the signal level of the high-frequency reception signal is strong, the gain of the intermediate frequency signal output from the frequency conversion circuit 48 with respect to the high-frequency reception signal has better distortion characteristics than that in the above case. Is slightly lower.

As a result, even if the dynamic range of the high frequency received signal is wide, the frequency conversion device 84 having good distortion characteristics and low noise characteristics can be realized.

In the present embodiment, the received electric field strength recognizing unit 51a outputs two levels of current depending on whether the signal level of the intermediate frequency signal is higher or lower than the predetermined signal level. However, it is not limited to this.
A current proportional to the signal level of the intermediate frequency signal detected by the reception electric field strength recognizing unit 51 may be output, and the current does not necessarily have to be proportional, and the larger the detected signal level is, the larger the current is. May be output, or the output current may be increased stepwise as the detected signal level increases.

It is needless to say that each modification described in each of the above embodiments can be applied to the fourth embodiment.

(Fifth Embodiment) Next, a fifth embodiment will be described.

FIG. 8 shows a block diagram of the frequency converter 85 of the fifth embodiment.

The frequency conversion device 85 of the present embodiment is the same as the reception electric field intensity recognition unit 51 of FIG. 6 in the fourth embodiment.
As a reception electric field strength recognition unit 51, the gain of the local oscillation signal amplification circuit 71 is controlled by controlling the voltage of the local oscillation signal amplification circuit 71.
b is used.

The frequency conversion circuit 85 of this embodiment is composed of a frequency conversion circuit 71, a filter 50, a received electric field strength recognition section 51b, and a local oscillation signal amplification circuit 71.

The frequency conversion circuit 48 and the filter 50 are the same as those in the fourth embodiment.

The reception electric field strength recognizing section 51b includes a filter 5
This circuit controls the gain of the local oscillation signal amplifier circuit 71 according to the signal level of the intermediate frequency signal output from 0.

FIG. 7 shows a circuit diagram of the local oscillation signal amplifier circuit 71.

The difference between the local oscillation signal amplifying circuit 71 and the local oscillation signal amplifying circuit 49 of the fourth embodiment is that the base of the bipolar transistor 58 is the reception electric field intensity recognition section 5.
It is a point connected to 1b. Other than this, it is the same as the local oscillation signal amplifier circuit 49 of the fourth embodiment.

Next, the operation of this embodiment will be described focusing on the difference from the fourth embodiment.

As in the fourth embodiment, the received electric field strength recognizing section 51b detects the signal level of the intermediate frequency signal output from the frequency conversion circuit 48 and passing through the filter 50.

The received electric field strength recognizing section 51b includes the filter 5
When it is detected that the signal level of the intermediate frequency signal output from 0 becomes higher than a predetermined signal level, the voltage output to the base of the bipolar transistor 58 of the local oscillation signal amplification circuit 71 is lowered. Further, when the reception electric field strength recognition unit 51b detects that the signal level of the intermediate frequency signal output from the filter 50 becomes weaker than the predetermined signal level, the bipolar transistor 5 is detected.
The voltage output to the base of 8 is increased. As described above, when the signal level of the signal of the intermediate frequency output from the filter 50 becomes higher than the predetermined signal level, the reception electric field intensity detection unit 51b lowers the output voltage and the signal level of the signal of the intermediate frequency becomes When the signal level becomes weaker than the predetermined signal level, the output voltage is increased. In this way, two levels of output voltage are output according to the signal level of the intermediate frequency signal.

When the voltage applied to the base of the bipolar transistor 58 increases, the gain of the local oscillation signal amplifier circuit 71 increases, and conversely the bipolar transistor 5
When the voltage applied to the base of 8 decreases, the gain of the local oscillation signal amplification circuit 71 decreases.

Therefore, the reception electric field intensity recognizing section 51b performs the above-described operation to control the gain of the local oscillation signal amplifying circuit 49, and as a result, when the signal level of the high frequency reception signal is strong, that is, detected. If the signal level of the intermediate frequency signal is stronger than the above predetermined signal level,
When the signal level of the local oscillation signal input to the frequency conversion circuit 48 is lowered and the signal level of the high frequency reception signal is weak, that is, when the signal level of the detected intermediate frequency signal is weaker than the predetermined signal level. , The signal level of the local oscillation signal input to the frequency conversion circuit 48 is raised.

Specifically, when the signal level of the high frequency received signal is weak, that is, when the signal level of the intermediate frequency is weaker than the predetermined signal level described above, LO in FIG.
A local oscillation signal near 10 decibels, that is, a local oscillation signal that minimizes NF is input to the frequency conversion circuit 48. On the other hand, when the signal level of the high-frequency reception signal is strong, that is, when the signal level of the intermediate frequency is higher than the above-mentioned predetermined signal level, in FIG. Such a local oscillation signal is input to the frequency conversion circuit 48.

Therefore, when the signal level of the high frequency received signal is weak, the frequency converter 71 has a characteristic of low noise, so that the influence of noise can be avoided, and at this time, CG is maximum, that is, frequency conversion is performed. The gain of the intermediate frequency signal output from the circuit 48 with respect to the high frequency reception signal is maximized.

On the other hand, when the signal level of the high frequency reception signal is strong, the gain of the intermediate frequency signal output from the frequency conversion circuit 48 with respect to the high frequency reception signal has good distortion characteristics, and the gain is higher than that in the above case. Is slightly lower.

As a result, it is possible to realize the frequency conversion device 85 having good distortion characteristics and low noise characteristics even when the dynamic range of the high frequency received signal is wide.

In the present embodiment, the received electric field strength recognizing section 51b outputs two levels of current depending on whether the signal level of the intermediate frequency signal is higher or lower than the predetermined signal level. However, it is not limited to this.
A current proportional to the signal level of the intermediate frequency signal detected by the reception electric field strength recognizing unit 51 may be output, and the current does not necessarily have to be proportional, and the larger the detected signal level is, the larger the current is. May be output, or the output current may be increased stepwise as the detected signal level increases.

Needless to say, each modification described in each of the above embodiments can be applied to the fifth embodiment.

(Sixth Embodiment) Next, a sixth embodiment will be described.

FIG. 9 shows the configuration of the frequency conversion apparatus of this embodiment.

The frequency converter of the present embodiment controls the gain of the local oscillation signal amplification circuit 72 by controlling the current of the local oscillation signal amplification circuit 72 as in the fourth embodiment. Unlike the fifth embodiment, the signal level of the high frequency reception signal is monitored and the above control is performed according to the signal level.

FIG. 10 shows a circuit diagram of the frequency converter 86 of this embodiment.

Of the frequency conversion circuit 86 of this embodiment, the frequency conversion circuit 6 and the bias circuit 40 are the same as those of the first embodiment. In addition, the local oscillation signal amplifier circuit 17
The constant current source 30 is different from the local oscillation signal amplifier circuit 17 of the first embodiment in a.

Further, the frequency conversion device 86 of the present embodiment.
Is provided with control circuits 100a and 110b for detecting the signal level of the high frequency reception signal and controlling the current of the local oscillation signal amplifier circuit according to the signal level.

The control circuit 110a includes bipolar transistors 90 and 92, diodes 91 and 95, and a resistor 9
It is composed of 3, 94.

Further, the control circuit 110b includes bipolar transistors 96, 97 and 104 and resistors 96, 97 and 9 respectively.
It is composed of 8, 99, 100 and 105.

The bipolar transistor 90 and the diode 91 are connected to each other and are grounded via resistors 93 and 94, respectively. The collector of the bipolar transistor 90 is connected to one of the resistors 99. The diode 91 is connected to the emitter of the bipolar transistor, and the collector of the bipolar transistor has a terminal Vcc for supplying power to the frequency conversion circuit 6.
(Mix) 1 and its base is connected to the diode 95. The diode 95 is connected to the terminal Vcc (Mix) 1 and also to the collector of the bipolar transistor 8.

The emitter of the bipolar transistor 96 is grounded through the resistor 98, one of the resistors 100 is connected to its base, and the other of the resistors 100 is connected to the emitter of the bipolar transistor 97. One of the resistors 102 is connected to the connection point between the resistor 100 and the bipolar transistor 97.
The other of is connected to the base of the bipolar transistor 104. And the bipolar transistor 104
Is connected to the respective emitters of the bipolar transistors 31 and 32, and the emitter thereof is grounded via the resistor 105. The other points are the same as those of the first and fourth embodiments.

Next, the operation of this embodiment will be described focusing on the difference from the fourth embodiment.

The portion corresponding to the control circuit 110a detects the signal level of the high frequency signal input from the terminal RFin2 as an increase / decrease in current, and the portion corresponding to the control circuit 110b detects the detected current by the local oscillation signal amplifier circuit. It is amplified to a current that can control the gain of 17a.

Although detailed description is omitted, when it is detected that the signal level of the high frequency reception signal becomes strong, the currents of the emitters of the bipolar transistors 31 and 32 of the local oscillation signal amplification circuit 17a decrease. Further, when it is detected that the signal level of the high frequency reception signal becomes weak, the currents of the bipolar transistors 31 and 32 increase. Therefore, when the signal level of the high frequency reception signal is weak, the local oscillation signal amplifier circuit 17a When the signal level of the high-frequency reception signal is high, the gain of the local oscillation signal amplification circuit 17a decreases. Therefore, similarly to the fourth embodiment, the distortion characteristics and the noise characteristics are good over a wide dynamic range.

(Seventh Embodiment) Next, a seventh embodiment will be described.

FIG. 9 shows the configuration of the frequency conversion apparatus of this embodiment.

The frequency conversion device of the present embodiment controls the gain of the local oscillation signal amplification circuit 72 by controlling the voltage of the local oscillation signal amplification circuit 72 as in the fifth embodiment. Unlike the fifth embodiment, the signal level of the high frequency reception signal is monitored and the above control is performed according to the signal level.

FIG. 11 shows a circuit diagram of the frequency converter 87 of this embodiment.

Of the frequency conversion circuit 87 of this embodiment, the frequency conversion circuit 6, the bias circuit 40, and the local oscillation signal amplification circuit 17 are the same as those in the first embodiment.

Further, the frequency converter 87 of the present embodiment.
Is provided with control circuits 120a and 120b for detecting the signal level of the high frequency reception signal and controlling the voltage of the local oscillation signal amplification circuit 17 according to the signal level.

The control circuits 120a and 120b include bipolar transistors 90 and 92 and diodes 91 and 95.
And resistors 93, 94 and 103.

The parts of the control circuits 120a and 120b are
The control circuit 110a is the same as the control circuit 110a according to the sixth embodiment except that the resistor 103 is provided, and thus the description thereof is omitted.

Next, the operation of this embodiment will be described focusing on the difference from the sixth embodiment.

The portion corresponding to the control circuit 112a detects the signal level of the high frequency signal input from the terminal RFin2 as an increase / decrease in current. The increase or decrease of the current is the resistance 103
The bipolar transistor 37 regulates the voltage applied to the bipolar transistor 31 and the bipolar transistor 32.

Therefore, although detailed description is omitted, when it is detected that the signal level of the high frequency reception signal becomes strong, the voltage of the collectors of the bipolar transistors 31 and 32 of the local oscillation signal amplification circuit 17a decreases. Also,
When it is detected that the signal level of the high frequency reception signal has become weak, the collector voltages of the bipolar transistors 31 and 32 rise.

Therefore, when the signal level of the high frequency reception signal is weak, the gain of the local oscillation signal amplification circuit 17a increases, and when the signal level of the high frequency reception signal is strong, the gain of the local oscillation signal amplification circuit 17a increases. Will decrease.
Therefore, similarly to the fifth embodiment, the distortion characteristic and the noise characteristic are good over a wide dynamic range.

The frequency converter of the present embodiment is
The circuit has been described as a circuit that converts a received high-frequency received signal into a signal of an intermediate frequency by combining with a local oscillation signal and outputs the signal, but the invention is not limited thereto. Also used as a circuit to convert the signal of the carrier frequency by the signal of the intermediate frequency or the baseband signal at the time of transmission to the signal of the transmission frequency or the signal of the intermediate frequency of the transmission output side by combining with the local oscillation signal. Can be done. In this case, an intermediate frequency signal or a signal obtained by modulating a carrier frequency signal with a baseband signal is input to the terminal RFin of the frequency conversion device, and a transmission frequency signal or a transmission output side intermediate frequency signal is input from the terminal IFout. Is output. As described above, the frequency conversion device according to the present embodiment can be used not only as a down mixer that converts a high-frequency signal into a lower-frequency signal than the signal,
It can also be used as an upmixer for converting a signal having a low frequency into a signal having a frequency higher than the signal.

The frequency-converted signal of the present invention is not limited to the high-frequency reception signal input to RFin of the present embodiment, but when the frequency conversion device of the present invention is used as an upmixer, it has an intermediate frequency. In short, the frequency-converted signal of the present invention, such as a signal obtained by modulating a carrier frequency signal with a signal or a baseband signal, may be a signal whose frequency is converted by being input to the frequency conversion device of the present invention.

Furthermore, the frequency converted signal of the present invention is not limited to the intermediate frequency signal output from IFout of the present embodiment, but when the frequency conversion device of the present invention is used as an up mixer, In short, the frequency-converted signal of the present invention, such as the signal of the transmission frequency output from the IFout of the form or the signal of the intermediate frequency on the transmission output side,
It only has to be a frequency-converted signal output from the frequency conversion device of the present invention.

A radio communication device provided with a receiving circuit for receiving a received signal and in which the frequency conversion device of the present invention is used in at least the receiving circuit also belongs to the present invention.

Further, the present invention also relates to a radio communication device which is provided with a transmission circuit for outputting a transmission signal and in which at least the transmission circuit uses the frequency conversion device of the present invention.

The radio communication device of the present invention includes, for example, mobile radio devices such as mobile phones, PHS, car phones, train phones, ship phones, aircraft phones, cordless phones, and pagers (registered trademark). .

[0213]

As is apparent from the above description, the present invention provides a frequency conversion device and a wireless communication device that can achieve both low noise characteristics and low distortion characteristics and have a wider dynamic range. You can

Further, in consideration of the above problems, the present invention provides a frequency conversion device and a wireless communication device in which both distortion characteristics and noise characteristics are better than those of the conventional ones, even if the performances of the transistors are the same. You can do it.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a frequency conversion device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a local oscillation signal amplifier circuit according to the first embodiment of the present invention.

FIG. 3 is a diagram showing characteristics of the frequency conversion device according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram of a frequency conversion device according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram of a frequency conversion device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a frequency conversion device according to a fourth embodiment and a fifth embodiment of the present invention.

FIG. 7 is a diagram showing a detailed configuration of a frequency conversion device according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a detailed configuration of a frequency conversion device according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a frequency conversion device according to a sixth embodiment and a seventh embodiment of the present invention.

FIG. 10 is a circuit diagram of a frequency conversion device according to a sixth embodiment of the present invention.

FIG. 11 is a circuit diagram of a frequency conversion device according to a seventh embodiment of the present invention.

FIG. 12 is a diagram showing characteristics in simulation of the frequency conversion device according to the first embodiment of the present invention.

FIG. 13 is a circuit diagram of a conventional frequency conversion device.

FIG. 14 is a diagram showing characteristics of a conventional frequency conversion device.

[Explanation of symbols]

1 terminal Vcc 2 terminal RFin 3 terminal LOin 4 terminal IFout 6 Frequency conversion circuit 7 Bipolar transistor 8 bipolar transistors 9 resistance 10 resistance 11 resistance 13 capacitors 14 Bipolar transistor 15 Bipolar transistor 16 bipolar transistor 17 Local oscillation signal amplification circuit 18 inductor 19 inductor 20 inductor 21 Capacitor 22 Capacitor 23 Capacitor 24 capacitors 25 capacitors 26 Resistance 40 bias circuit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junji Ito             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hideo Nakano             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Naoki Okamoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hidehiko Kurimoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Masanori Nakamura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (34)

[Claims] 1. A constant current source for supplying a predetermined current, a bias circuit, and a frequency conversion circuit, wherein the bias circuit receives a current from the constant current source, and a first amplification circuit. A second amplifier circuit supplied with a current from the constant current source, a first resistor connected between the first amplifier circuit and the second amplifier circuit, and the first resistor. A second resistor, one of which is connected to the connection point with the second amplifier circuit and the other of which is grounded; and a third resistor of which one is connected to the connection point, the third resistor A first input terminal for supplying a frequency-converted signal is connected to the other of the resistors, and the frequency conversion circuit is connected to the other of the third resistors and supplied from a second input terminal. Input an oscillation signal and synthesize the frequency converted signal and the local oscillation signal. It allows the frequency to be converted signal and outputs a frequency-converted signal is a frequency converted signal to an output terminal, the second is the input terminal and the output terminal respectively a pair a certain frequency converter. 2. The frequency conversion circuit includes third, fourth, and fifth amplification circuits, the third amplification circuit being connected to the other of the third resistors, and the fourth amplification circuit. A circuit connected to the third amplifier circuit and to one of the second input terminals, a fifth amplifier circuit connected to the third amplifier circuit, and a second circuit Connected to the other of the input terminals, one of the output terminals is connected to the fourth amplifier circuit, the other of the output terminals is connected to the fifth amplifier circuit, The frequency conversion device according to claim 1, wherein the fifth amplifier circuit forms a differential circuit. 3. The frequency conversion device according to claim 2, wherein the third amplifier circuit is a transistor, and the emitter of the third amplifier circuit is grounded via an inductor. 4. The frequency conversion device according to claim 2, wherein the third amplifier circuit is a transistor, and an emitter of the third amplifier circuit is grounded via a capacitor and an inductor connected in parallel with each other. 5. The first amplifying circuit and the third amplifying circuit are transistors, and the emitter of the first amplifying circuit and the emitter of the third amplifying circuit are grounded via resistors, respectively. The frequency conversion device according to claim 2, which is provided. 6. The bias circuit has a fourth resistor connected to one of the third resistors, the first input terminal is a pair, and one and the other of the input terminals are , The other of the third resistors and the other of the fourth resistors, respectively, the frequency conversion circuit, the third, fourth, fifth, sixth, seventh, and eighth amplifier circuit The third amplifier circuit is connected to the other of the third resistors, the fourth amplifier circuit is connected to the other of the fourth resistors, and the fifth and sixth amplifier circuits are , And the third and second amplification terminals, respectively, and one and the other of the second input terminals, and one and the other of the output terminals, respectively, and the seventh and eighth amplification circuits. Are both connected to the fourth amplifier circuit, and are respectively connected to the second input circuit. Connected to the other and one of the terminals and to one and the other of the output terminals, respectively, the fifth and sixth amplifier circuits form a differential circuit, and the seventh and eighth amplifier circuits are The frequency conversion device according to claim 1, wherein the frequency conversion device forms a differential circuit. 7. The bias circuit comprises a ninth amplifier circuit which is supplied with current from the constant current source, and a fourth amplifier circuit which is connected between the first amplifier circuit and the ninth amplifier circuit. And a fifth resistor, one of which is connected to the connection point between the fourth resistor and the ninth amplifier circuit and the other of which is grounded, and one of which is connected to the connection point and the other of which is A sixth resistor connected to the outside of a bias circuit, the first input terminal is a pair, and one and the other of the input terminals are respectively the other of the third resistor and the third resistor. 6 is connected to the other of the resistors, the frequency conversion circuit has a third, fourth, fifth, sixth, seventh, and eighth amplification circuit, the third amplification circuit is the Connected to the other of the third resistors, the fourth amplifier circuit is connected to the other of the sixth resistors, Fifth and sixth amplifier circuits are both connected to the third amplifier circuit, and are respectively connected to one and the other of the second input terminals, and are respectively connected to one and the other of the output terminals, The seventh and eighth amplifier circuits are both connected to the fourth amplifier circuit, and are respectively connected to the other and one of the second input terminals, and are respectively connected to one and the other of the output terminals. The frequency conversion device according to claim 1, wherein the fifth and sixth amplification circuits form a differential circuit, and the seventh and eighth amplification circuits form a differential circuit. 8. The frequency conversion device according to claim 6, wherein one of the first input terminals is grounded via a capacitor. 9. The third amplifier circuit and the fourth amplifier circuit are transistors, respectively, and the emitter of the third amplifier circuit and the emitter of the fourth amplifier circuit are grounded via inductors. The frequency conversion device according to any one of claims 6 to 8. 10. The third amplifier circuit and the fourth amplifier circuit are each a transistor, and the emitter of the third amplifier circuit and the emitter of the fourth amplifier circuit are connected via a capacitor. The frequency conversion device according to any one of claims 6 to 8, wherein the emitter of the third amplification circuit and the emitter of the fourth amplification circuit are grounded via an inductor. 11. The third amplifying circuit and the fourth amplifying circuit are transistors, and one of the inductors is connected to the emitter of the third amplifying circuit and the emitter of the fourth amplifying circuit. 9. The frequency conversion device according to claim 6, wherein the other of the inductors is connected to each other, and is grounded via a resistor at a midpoint of a wire connecting the other of the inductors. 12. The third amplifier circuit and the fourth amplifier circuit are transistors, and one of the inductors is connected to the emitter of the third amplifier circuit and the emitter of the fourth amplifier circuit, respectively. ,
9. The other of the inductors is connected to each other, and is grounded via the inductor at the midpoint of the wiring connecting the other of the inductors.
The frequency conversion device according to any one of 1. 13. The frequency conversion device according to claim 1, further comprising a local oscillation signal amplification circuit which is connected to the second input terminal, amplifies the local oscillation signal, and outputs the amplified signal to the frequency conversion circuit. 14. The local oscillation signal amplification circuit includes a tenth amplification circuit and an eleventh amplification circuit for inputting the local oscillation signal supplied from the second input terminal, and the tenth amplification circuit. 14. The frequency conversion device according to claim 13, wherein the amplifier circuit and the eleventh amplifier circuit form a differential circuit. 15. The frequency conversion device according to claim 14, wherein the local oscillation signal amplifier circuit includes a constant current supply circuit that supplies a predetermined current to the tenth amplifier circuit and the eleventh amplifier circuit. . 16. The frequency conversion device according to claim 14, wherein one of the second input terminals is grounded via a capacitor. 17. The local oscillation signal amplification circuit includes a first resonance circuit and a second resonance circuit in which a capacitor and an inductor are connected in parallel to each other, and the tenth amplification circuit and the eleventh amplification circuit. Are transistors, the base of the tenth amplifier circuit and the base of the eleventh amplifier circuit are respectively connected to one and the other of the second input terminals, and the emitter of the tenth amplifier circuit and the The emitters of the amplifier circuits of 11 are connected to each other, the constant current supply circuit is connected to the connection point, and the collector of the tenth amplifier circuit is connected to one of the first resonance circuits. And the other of the first resonance circuits is supplied with a bias from a bias supply source, and the collector of the eleventh amplification circuit is connected to one of the second resonance circuits. The other of the second resonance circuits receives a bias supply from the bias supply source, and the collector of the tenth amplification circuit and the collector of the eleventh amplification circuit are respectively connected to the frequency conversion circuit. The frequency conversion device according to any one of claims 14 to 16, which is connected. 18. The local oscillation signal amplifier circuit has a resistor, one of which is connected to the other of the first resonant circuit and the other of the second resonant circuit, and the other of which is connected to the bias supply source. Item 17. The frequency conversion device according to item 17. 19. The local oscillation signal amplifier circuit has a diode, one of which is connected to the other of the first resonance circuit and the other of the second resonance circuit, and the other of which is connected to the bias supply source. 17. The frequency converter according to item 17. 20. The frequency conversion device according to claim 13, further comprising a control circuit that controls an injection level of the local oscillation signal injected into the frequency conversion circuit according to a predetermined condition. 21. The predetermined condition is a signal level of the frequency conversion signal output from the frequency conversion circuit, and the control circuit is a signal level of the frequency conversion signal output from the frequency conversion circuit. 21. The frequency conversion device according to claim 20, further comprising a control circuit for controlling an injection level of the local oscillation signal injected into the frequency conversion circuit in accordance with the above. 22. The frequency conversion device according to claim 21, wherein the control circuit decreases the injection level of the local oscillation signal when the signal level of the frequency conversion signal increases. 23. A detection circuit for detecting the signal level is provided, and a filter for reducing a distortion component of the frequency conversion signal is inserted between the frequency conversion circuit and the detection circuit. 22. The frequency conversion device according to any one of 22. 24. The frequency conversion device according to claim 22, wherein the control circuit reduces the gain of the local oscillation signal amplification circuit when the signal level of the frequency conversion signal increases. 25. The frequency conversion device according to claim 24, wherein reducing the gain of the local oscillation signal amplifier circuit means reducing a current of the local oscillation signal amplifier circuit. 26. The frequency conversion device according to claim 24, wherein reducing the gain of the local oscillation signal amplifier circuit means reducing a current of the local oscillation signal amplifier circuit. 27. The predetermined condition is a signal level of the frequency-converted signal injected into the frequency conversion circuit, and the control circuit is configured to control the local part according to the signal level of the frequency-converted signal. 21. The frequency conversion device according to claim 20, wherein the injection level of the oscillation signal is changed. 28. The frequency conversion device according to claim 27, wherein the control circuit decreases the signal level of the frequency converted signal when the signal level of the frequency converted signal increases. 29. The frequency conversion device according to claim 28, wherein reducing the signal level means reducing the gain of the local oscillation signal amplification circuit. 30. The frequency conversion device according to claim 29, wherein reducing the signal level means reducing a current of the local oscillation signal amplifier circuit. 31. The frequency conversion device according to claim 29, wherein decreasing the signal level means decreasing the voltage of the local oscillation signal amplifier circuit. 32. A control circuit for decreasing the current output to the constant current supply circuit when the signal level of the frequency conversion signal increases, wherein the constant current supply circuit includes twelfth, thirteenth and fourteenth. An amplifier circuit, and seventh, eighth, ninth, tenth, and eleventh resistors, wherein the twelfth, thirteenth, and fourteenth amplifier circuits are transistors, respectively, and A seventh resistor is connected between the base of the amplifier circuit and the emitter of the fourteen amplifier circuit, and a seventh resistor is connected between the base of the thirteenth amplifier circuit and the emitter of the fourteenth amplifier circuit. 8 resistors are connected, and the twelfth amplifier circuit emitter and the thirteenth amplifier circuit emitter are respectively connected to the ninth resistor and the first resistor.
It is grounded through a resistor of 0, the base and collector of the 14th amplifier circuit are connected through the 11th resistor, and the collector of the 14th amplifier circuit is connected to the control circuit. The collector of the thirteenth amplifier circuit is connected to the base of the fourteenth amplifier circuit, and the collector of the twelfth amplifier circuit is connected to the tenth and eleventh amplifier circuits. 20. Connected to an amplifier circuit.
The frequency conversion device according to any one of 1. 33. A control circuit for decreasing the output voltage when the signal level of the frequency conversion signal increases, wherein the local oscillation signal amplification circuit has an emitter of the other of the first resonance circuit and the second resonance circuit. A transistor having a collector connected to the bias supply source and a base connected to the output of the control circuit, and the constant current supply circuit includes twelfth, thirteenth, and fourteenth amplification circuits. A circuit and a seventh, an eighth, a ninth, a tenth, and an eleventh resistor, and the twelfth, thirteenth, and fourteenth amplification circuits are transistors, respectively, and the twelfth amplification circuit. A seventh resistor is connected between the base of the circuit and the emitter of the fourteenth amplifying circuit, and an eighth resistor is connected between the base of the thirteenth amplifying circuit and the emitter of the fourteenth amplifying circuit. The resistance of is connected Cage, wherein the twelfth amplification circuit emitter and the second 13 amplifier circuit emitter of the respective ninth resistor, and the first
It is grounded via a resistance of 0, the base and collector of the 14th amplification circuit are connected via the 11th resistance, and the collector of the 14th amplification circuit is connected to the bias supply. A collector of the thirteenth amplification circuit and a base of the fourteenth amplification circuit are connected, and a collector of the twelfth amplification circuit is connected to the tenth and eleventh amplification circuits. 20. Connected to a circuit
The frequency conversion device according to any one of 1. 34. A wireless communication device comprising a receiving circuit for receiving a received signal, wherein the frequency converting device according to claim 1 is used in the receiving circuit.