JPH09312587A - Radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove the influence of a leakage transmission signal leaked to a reception circuit from a transmission circuit through an antenna sharing circuit in a radio communication requirement using a frequency dividing duplex system. SOLUTION: The transmission circuit 40 and the reception circuit 20 using respectively different frequencies are connected to a common antenna 11 through an antenna sharing circuit 12 in this radio communication equipment. A first directional connector 51 is interposed between the power amplifier circuit 45 of the transmission circuit and the antenna sharing circuit to extract a part of the output signal of the transmission circuit. The amplitude and the phase of an extracted signal are adjusted by an attenuator 53 and a phase shifter circuit 54 to generate a cancelling signal for cancelling the leakage transmission signal STL the transmission circuit by way of the antenna sharing circuit. This cancelling signal is injected to the reception circuit by a second directional connector 52 interposed between the antenna sharing circuit and the reception circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device using a system (frequency division duplex system) in which a frequency band of a transmission signal and a frequency band of a reception signal are different.

[0002]

2. Description of the Related Art Conventionally, there has been known a radio communication system adopting a frequency division duplex system such as an analog cellular system and a CDMA digital cellular system.

In a terminal device of such a wireless communication system, an antenna shared circuit (characteristic) as shown in FIG. 10 is used in order to share a single antenna in different transmission frequency bands and reception frequency bands. Duplexer) is used.

Although not shown, this shared circuit has three ports on the antenna side, the transmitting side and the receiving side, and a band pass filter of the transmission band BTX is connected between the antenna side and the transmitting side ports. At the same time, a band pass filter of the reception band BRX is connected between the antenna side port and the reception side port.

In order to reduce the loss of transmission power, it is desired to reduce the insertion loss in the transmission band between the antenna port and the transmission port. Further, in order to improve the reception sensitivity, it is desired to reduce the insertion loss in the reception band between the antenna port and the reception port.

[0006]

By the way, in the terminal device of the wireless communication system as described above, the large-amplitude transmission signal output from the transmission circuit is received from the transmission port of the antenna sharing circuit via the reception port. Leakage into the circuit is inevitable.

If the amplitude of this leaky transmission signal is large, the receiving circuit will be in a large-amplitude operating state, and the receiving performance will deteriorate. Therefore, in order to sufficiently suppress the leakage transmission signal, it is necessary to increase the isolation between the transmission port and the reception port of the shared antenna circuit, that is, to sufficiently increase the cutoff characteristic in the transmission band of the bandpass filter on the reception port side. is there.

However, in order to sufficiently increase the cutoff characteristic, it is necessary to increase the number of stages of the bandpass filter on the receiving port side, which causes an increase in insertion loss and, as a result, lowers the receiving sensitivity. There was a problem.

Further, in a terminal device that employs a linear modulation method in which the envelope changes according to the modulation signal as the modulation method of the transmission signal, for example, as shown in FIG.
When a large-amplitude jamming signal SITFR, such as a transmission signal of a terminal of another wireless communication system that uses the same frequency band, is input to the receiving circuit from the outside of the terminal through the antenna, it is shown by parallel diagonal lines in FIG. AM of leaky transmission signal STL
The component causes intermodulation, and the intermodulation component SCM causes the interfering signal SIT.
Spurious occurs near FR.

Then, the interference signal SITFR and the desired reception signal S
If the frequency is close to RX, spurious will partially enter the band of the desired reception signal SRX and become noise,
There was a problem of degrading reception sensitivity.

In view of the above points, the object of the present invention is to
It is possible to eliminate the influence of leaked transmission signals that leak from the transmission circuit to the reception circuit via the shared antenna circuit.
A wireless communication device is provided.

[0012]

In order to solve the above-mentioned problems, a wireless communication apparatus according to the present invention includes a transmission circuit for transmitting a transmission signal in a first frequency band and a reception processing for a reception signal in a second frequency band. A receiving circuit, a transmitting / receiving antenna, an antenna common circuit provided between the transmitting circuit and the receiving circuit, and the transmitting / receiving antenna, an extracting unit for extracting a part of a transmission signal of the transmitting circuit, and the extracting circuit. A cancellation signal generation for adjusting the amplitude and phase of the signal extracted by the means to generate a cancellation signal for canceling the leakage component of the transmission signal leaking from the transmission circuit to the reception circuit via the antenna shared circuit. Means and injecting means for injecting the cancellation signal into the receiving circuit.

In the wireless communication device having the above-mentioned configuration, the leakage component of the transmission signal, which is included in the input signal of the receiving circuit and leaks through the antenna shared circuit, is the cancellation signal generated by the cancellation signal generation means. Is added to the received signal, so that it is removed from the received signal.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a wireless communication apparatus according to the present invention will be described below with reference to FIG.

FIG. 1 shows the configuration of the first embodiment of the present invention.
Shown in In this embodiment, the transmitting / receiving antenna 11
Is connected to the antenna port 12 a of the antenna sharing circuit 12. The antenna sharing circuit 12 includes a transmission side port 12t and a reception side port 12r, and the transmission band BTX shown in FIG. 10 described above is used as a pass band between the antenna port 12a and the transmission side port 12t. The band pass filter has an antenna port 12a and a port 1 on the receiving side.
The band pass filters having the reception band BRX shown in FIG. 10 as a pass band are respectively connected between 2r and 2r.

First, the receiving system will be described. The RF signal from the reception port 12r of the antenna sharing circuit 12 passes through the low noise amplification circuit 21 of the reception circuit 20 and the mixing circuit 2
2 is supplied. The local oscillation signal from the local oscillation circuit 23 is supplied to the mixing circuit 22, the RF signal from the low noise amplification circuit 21 is converted into an intermediate frequency signal, and the intermediate frequency amplification circuit 24 passes the signal to the demodulation circuit 25. It is supplied and demodulated.

The output of the intermediate frequency amplifier circuit 26 is also supplied to the received power detection circuit 26. The output of the received power detection circuit 26 is negatively fed back to the intermediate frequency amplifier circuit 24, and the gain of the intermediate frequency amplifier circuit 24 is controlled.

The output of the demodulation circuit 25 is supplied to the baseband signal processing circuit 31, where it is subjected to predetermined signal processing to reproduce received information such as a voice signal. A part of the reproduced reception information is taken into the microcomputer 32.

Next, the transmission system will be described. In the baseband signal processing circuit 31, predetermined signal processing is performed on transmission information such as a voice signal. The output signal of the baseband signal processing circuit 31 is supplied to the modulation circuit 41 of the transmission circuit 40 and modulated. The output of the modulation circuit 41 is supplied to the mixing circuit 43 through the intermediate frequency amplification circuit 42.

The mixing circuit 43 includes a local oscillation circuit 23.
From the intermediate frequency amplifier circuit 4
The intermediate frequency signal from 2 is converted to an RF signal. This R
The F signal is supplied to the transmission port 12t of the antenna sharing circuit 12 through the drive amplification circuit 44 and the power amplification circuit 45.

The intermediate frequency amplifier circuit 42 and the drive amplifier circuit 44 are supplied with a transmission power control signal from the transmission power control circuit 46, and their gains are controlled.
The transmission power control signal is generated based on the control signals from the reception power detection circuit 26 and the microcomputer 32.

Next, the removal of the leakage component of the transmission signal will be described. In this embodiment, the antenna sharing circuit 12
Power transmission circuit 12 of the transmission port 12t and the transmission circuit 40
And the first directional coupler 51 is interposed between
Receiving port 12r of antenna sharing circuit 12 and receiving circuit 2
The second directional coupler 5 between the low noise amplification circuit 21 and the low noise amplification circuit 21.
2 is inserted. The attenuator 53 and the phase shift circuit 54 are connected in series between the bidirectional couplers 51 and 52 to form the leakage cancellation signal generation circuit 50. The first directional coupler 51 constitutes an extracting means for extracting a part of the transmission signal, and the second directional coupler 52 supplies the cancellation signal from the leakage cancellation signal generation circuit 50 to the reception circuit 20. The injection means is configured.

In this case, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50 leaks from the transmission circuit 40 to the reception circuit 20 via the antenna shared circuit 12. On the input side of the low-noise amplification circuit 21 of the reception circuit 20, the bidirectional coupler 5 has the same amplitude and opposite phase with respect to the leakage transmission signal STL.
The attenuation amount of the attenuator 53 of the leakage cancellation signal generation circuit 50 and the phase shift amount of the phase shift circuit 54 are set, including the attenuation and phase shift at 1, 52.

As a result, in the first embodiment, the leaky transmission signal STL is canceled by the leaking canceling signal at the input side of the low noise amplifying circuit 21 of the receiving circuit 20.

Therefore, the cutoff characteristics of the bandpass filter (not shown) on the reception port 12r side of the antenna sharing circuit 12 in the transmission band can be relaxed, and as a result, the insertion loss of the reception band can be reduced. Therefore, the reception sensitivity can be improved and the influence of the leakage transmission signal STL can be eliminated.

[Second Embodiment] Next, a second embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG.

In FIG. 2, the parts corresponding to those in FIG. 1 are designated by the same reference numerals and the description thereof is partially omitted.

In the second embodiment, a first directional coupler 51 as an extracting means is inserted between the transmission port 12t of the antenna sharing circuit 12 and the power amplification circuit 45 of the transmission circuit 40. Like the first embodiment, the second directional coupler 52 as an injection means is interposed between the reception port 12r of the antenna sharing circuit 12 and the low noise amplification circuit 21 of the reception circuit 20. However, the configuration of the leakage cancellation signal generation circuit is different from that of the first embodiment.

That is, in the second embodiment, the attenuator 53 and the phase shift circuit 54 are connected in series between the directional couplers 51 and 52, and the directional coupler 51 and the directional coupler 51 are connected together. A bandpass filter 55 is inserted between the attenuators 53 to form a leakage cancellation signal generation circuit 50A.

This bandpass filter is used to extract only the component of the transmission signal and remove the noise signal or spurious signal generated in the transmission circuit 40.

In this case, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50A leaks from the transmission circuit 40 to the reception circuit 20 via the antenna shared circuit 12. The leakage transmission signal STL is attenuated and phase-shifted in the bidirectional couplers 51 and 52 and the bandpass filter 55 so that the input side of the low noise amplification circuit 21 of the reception circuit 20 has equal amplitude and opposite phase. Including, the attenuation amount of the attenuator 53 of the leakage cancellation signal generation circuit 50A and the phase shift amount of the phase shift circuit 54 are set.

As a result, in the embodiment of FIG. 2, the leaky transmission signal STL is canceled by the leak canceling signal at the input side of the low noise amplifying circuit 21 of the receiving circuit 20, so that the receiving port 12r of the antenna sharing circuit 12 is cancelled. On the side, the blocking characteristics in the transmission band of the band pass filter (not shown) as described above can be relaxed, and as a result, the insertion loss in the reception band can be reduced, and the reception sensitivity can be improved.
The influence of the leaked transmission signal STL can be eliminated.

Further, by providing the bandpass filter 55, it is possible to prevent a noise signal or a spurious signal generated in the transmission circuit 40 from flowing into the reception circuit 20.

[Third Embodiment] Next, a third embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG. In FIG. 3, parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals, and part of the description will be omitted.

Also in the third embodiment, the first directional coupler 51 is interposed between the transmission port 12t of the antenna sharing circuit 12 and the power amplification circuit 45 of the transmitting circuit 40, and the antenna sharing circuit is also provided. The second directional coupler 52 is interposed between the reception port 12r of 12 and the low noise amplification circuit 21 of the reception circuit 20, as in the first and second embodiments. However, the configuration of the leakage cancellation signal generation circuit is different from that of the first embodiment.

That is, in the third embodiment, the variable attenuator 53 is provided between the directional couplers 51 and 52.
V and the variable phase shift circuit 54V are connected in cascade, and
A bandpass filter 55 is interposed between the directional coupler 51 and the attenuator 53 to form a leakage cancellation signal generation circuit 50B.

The variable attenuator 53V and the variable phase shift circuit 54V are controlled in their attenuation amount and phase shift amount by the microcomputer 32, respectively. There are two control methods.

The amplitude and phase characteristics of the leaky transmission signal STL leaking from the transmission circuit 40 to the reception circuit 20 via the shared antenna circuit 12 have frequency characteristics in the transmission bandwidth. Therefore, the microcomputer 32 controls the attenuation amount and the phase shift amount of the variable attenuator 53V and the variable phase shift circuit 54V so as to correct the frequency characteristic of the leakage transmission signal STL according to the transmission signal frequency. By this control, the leakage cancellation characteristic can be improved in the transmission band BTX.

A user interface (not shown) is connected to the microcomputer 32, and an operation for controlling the amount of attenuation in the variable attenuator 53V and the amount of phase shift in the variable phase shift circuit 54V is connected to this user interface. Section is provided. Then, the microcomputer 32 controls the amount of attenuation in the variable attenuator 53V and the amount of phase shift in the variable phase shift circuit 54V according to an external operation by the user through the operation unit. By performing this control at the time of shipment, the directional coupler 5
1, shared circuit 12, individual variation of directional coupler 52,
And the individual variation of the leakage cancellation signal generation circuit 50B is corrected, and the leakage cancellation characteristic is improved.

The bandpass filter 55 is for removing a noise signal or a spurious signal generated in the transmission circuit 40, as described in the second embodiment.

The attenuation amount of the variable attenuator 53V and the variable phase shift circuit 54V are passed without passing through the microcomputer 32.
The amount of phase shift may be controlled from outside the terminal directly and electrically or mechanically.

In the third embodiment, the variable attenuator 5 is used.
The attenuation amount of 3V and the phase shift amount of the variable phase shift circuit 54V are set as appropriate.
By adjusting, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50B leaks from the transmission circuit 40 to the reception circuit 20 via the antenna shared circuit 12. It becomes possible to control the transmission signal STL so that the input side of the low noise amplification circuit 21 of the reception circuit 20 has the same amplitude and opposite phase.

Therefore, in the embodiment of FIG. 3, the phase shift of the leakage canceling signal is performed according to the change of the transmission signal frequency and the variation of each radio communication device such as the antenna sharing circuit 12 and the directional couplers 51 and 52. It is possible to change the amount and the amplitude amount, and the leaky transmission signal STL is canceled at the input side of the low noise amplifying circuit 21 of the receiving circuit 20 with the leaking canceling signal.
On the side, the blocking characteristic in the transmission band of the band pass filter (not shown) as described above can be relaxed, and as a result, the insertion loss in the reception band can be reduced,
The reception sensitivity is improved, and the influence of the leaked transmission signal STL can be eliminated.

Further, by providing the band pass filter 55, it is possible to prevent a noise signal or a spurious signal generated in the transmission circuit 40 from flowing into the reception circuit 20.

[Fourth Embodiment] Next, a fourth embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG. In the embodiment of FIG. 4,
The parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be partially omitted.

In the embodiment shown in FIG. 4, the first directional coupler 51 is inserted between the power amplification circuit 45 and the drive amplification circuit 44 of the transmission circuit 40, and the second directional coupler 5 is used.
2 is inserted between the reception port 12r of the antenna sharing circuit 12 and the low noise amplification circuit 21 of the reception circuit 20. Then, the attenuator 53 and the phase shift circuit 54 are connected in series between the bidirectional couplers 51 and 52 to form a leakage cancellation signal generation circuit 50C.

In this case, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50C leaks from the transmission circuit 40 to the reception circuit 20 via the antenna shared circuit 12. The leakage transmission signal STL is leaked at the input side of the low noise amplification circuit 21 of the reception circuit 20 so as to have equal amplitude and opposite phase, including attenuation and phase shift in the bidirectional couplers 51 and 52. The amount of attenuation of the attenuator 53 of the cancellation signal generation circuit 50C and the phase shift circuit 54
The phase shift amount is set in the same manner as in the first embodiment. In addition, the other configurations are the same as those of the first embodiment.

As a result, in the fourth embodiment, the leak transmission signal STL is canceled by the leak cancel signal at the input side of the low noise amplifier circuit 21 of the receiving circuit 20, as in the above-described embodiments. The blocking characteristic in the transmission band of the band pass filter (not shown) on the reception port 12r side of the antenna sharing circuit 12 can be relaxed, and as a result, the insertion loss in the reception band can be reduced. As a result, the reception sensitivity is improved and the influence of the leaked transmission signal STL can be eliminated.

Further, in the fourth embodiment,
In particular, by inserting the directional coupler 51 between the power amplification circuit 45 of the transmission circuit 40 and the drive amplification circuit 44, it is possible to avoid a decrease in transmission output due to the insertion loss of the directional coupler 51. . That is, when the directional coupler 51 is provided on the output side of the power amplification circuit 45 of the transmission circuit 40, the transmission signal output is reduced due to the loss in the directional coupler 51. In the form of
Since the transmission signal component is extracted by the directional coupler 51 in the preceding stage of the power amplification circuit 45, the transmission signal output which is the output of the power amplification circuit 45 in the directional coupler 51 does not decrease.

[Fifth Embodiment] Next, a fifth embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG. In FIG. 5, parts corresponding to those in FIG.

In the fifth embodiment, the first directional coupler 51 is interposed between the transmission port 12t of the antenna sharing circuit 12 and the power amplification circuit 45 of the transmission circuit 40, and the second directional coupler 51 is provided. The directional coupler 52 is interposed between the low noise amplification circuit 21 and the mixing circuit 22 of the reception circuit 20. As the low noise amplification circuit 21, an amplification circuit having a large linear operation amplitude range is used.

An attenuator 53 and a phase shift circuit 54 are connected in series between the bidirectional couplers 51 and 52,
The leakage cancellation signal generation circuit 50D is formed.

Also in the fifth embodiment, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50D is transmitted via the antenna sharing circuit 12 to the transmission circuit 40. The leaky transmission signal STL leaking from the receiving circuit 20 to the receiving circuit 20 is attenuated and shifted in the bidirectional couplers 51 and 52 so that the output side of the low noise amplification circuit 21 of the receiving circuit 20 has equal amplitude and opposite phase. Including the phase and the attenuator 53 of the leakage cancellation signal generation circuit 50D.
And the phase shift amount of the phase shift circuit 54 are set. Others are the same as those in the first embodiment.

With the above configuration, the leaky transmission signal STL is canceled by the leaking canceling signal at the output side of the low noise amplifying circuit 21 of the receiving circuit 20 in the fifth embodiment as well. The blocking characteristic in the transmission band of the band pass filter (not shown) on the reception port 12r side of the antenna sharing circuit 12 can be relaxed, and as a result, the insertion loss of the reception band can be reduced. As a result, the reception sensitivity is improved and the influence of the leaked transmission signal STL can be eliminated.

In addition, in the fifth embodiment,
In particular, by inserting the directional coupler 52 at the output side of the low-noise amplifier circuit 21 of the receiving circuit 20, it is possible to avoid a decrease in noise figure due to the insertion loss of the directional coupler 52. That is, when the transmission signal component as the leakage transmission signal STL is injected into the input stage of the receiving circuit 20, the loss in the directional coupler 52 directly increases the noise figure and deteriorates the reception sensitivity. According to the embodiment of the present invention, since the directional coupler 52 is inserted on the output side of the low noise amplification circuit 21 of the receiving circuit 20, the directional coupler 52 is
The effect of the noise figure is reduced, and the above-mentioned drawbacks are improved.

[Sixth Embodiment] Next, a sixth embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG. 6, parts corresponding to those in FIG. 1 described above are denoted by the same reference numerals, and a description thereof is partially omitted.

In the sixth embodiment, the first directional coupler 51 is inserted between the transmission port 12t of the antenna sharing circuit 12 and the power amplifying circuit 45 of the transmitting circuit 40, and the antenna sharing circuit is used. The second directional coupler 52 is interposed between the reception port 12r of 12 and the low noise amplification circuit 21 of the reception circuit 20.

An amplifier circuit 56 is inserted between the bidirectional couplers 51 and 52 in place of the attenuator 53 of the first embodiment, and the amplifier circuit 56 and the phase shift circuit 54 are cascaded. To form a leakage cancellation signal generation circuit 50E.

In the sixth embodiment, the transmission circuit 40 is connected to the reception circuit 2 via the leakage cancellation signal generation circuit 50E.
The leakage cancellation signal supplied to 0 is the antenna shared circuit 12
The leaky transmission signal STL leaking from the transmission circuit 40 to the reception circuit 20 via the bidirectional coupler so that the input side of the low noise amplification circuit 21 of the reception circuit 20 has equal amplitude and opposite phase. The gain of the amplifier circuit 56 of the leakage cancellation signal generation circuit 50E and the amount of phase shift of the phase shift circuit 54 are set, including attenuation and phase shift at 51 and 52.

As a result, in the sixth embodiment, the leakage transmission signal STL is canceled by the leakage canceling signal at the input side of the low noise amplifying circuit 21 of the receiving circuit 20.

In the case of the sixth embodiment, the amplifier circuit 5
By securing a predetermined gain at 6, compared with the case where the attenuator 53 of the first embodiment of FIG. 1 is used,
The cutoff characteristics in the transmission band of the above-described bandpass filter (not shown) on the reception port 12r side of the antenna sharing circuit 12 can be further relaxed, and as a result,
It is possible to further reduce the insertion loss in the reception band, improve the reception sensitivity, and eliminate the influence of the leaked transmission signal STL.

As shown in FIG. 7, a variable gain amplifying circuit 56A is provided in place of the amplifying circuit 56, and the user performs a gain adjusting operation through a user interface (not shown), so that the microcomputer as shown in FIG. 32 may be configured to control the gain of the variable gain amplifier circuit 56A. In that case, by adjusting the amplitude of the leakage cancellation signal and the gain of the variable gain amplification circuit 56A, it becomes easy to generate a more appropriate leakage cancellation signal.

[Seventh Embodiment] A seventh embodiment of the radio communication apparatus according to the present invention will be described with reference to FIG. In FIG. 8, parts corresponding to those in FIG.

In the seventh embodiment, the first directional coupler 51 is interposed between the transmission port 12t of the antenna sharing circuit 12 and the power amplification circuit 45 of the transmitting circuit 40, and the antenna sharing circuit is used. The second directional coupler 52 is interposed between the reception port 12r of 12 and the low noise amplification circuit 21 of the reception circuit 20, and the bidirectional coupler 51,
An amplifying circuit 56 is interposed between the two instead of the attenuator 53 of the embodiment shown in FIG. 2, the amplifying circuit 56 and the phase shift circuit 54 are connected in cascade, and the directional coupling is performed. Bowl 5
The band elimination filter 55 is inserted between 1 and the amplifier circuit 56 to form the leakage cancellation signal generation circuit 50F.

Also in the seventh embodiment, the leakage cancellation signal supplied from the transmission circuit 40 to the reception circuit 20 via the leakage cancellation signal generation circuit 50F is transmitted via the antenna sharing circuit 12 to the transmission circuit 40. The leaky transmission signal STL leaking from the receiving circuit 20 to the receiving circuit 20 at the input side of the low noise amplifying circuit 21 of the receiving circuit 20, so that the bidirectional couplers 51 and 52 and the band elimination filter have equal amplitude and opposite phase. The gain of the amplifier circuit 56 of the leakage cancellation signal generation circuit 50F and the amount of phase shift of the phase shift circuit 54 are set, including the attenuation and phase shift at 55.

With the above configuration, in the seventh embodiment, at the input side of the low noise amplification circuit 21 of the reception circuit 20, the leakage transmission signal STL is canceled by the leakage cancellation signal, and at the same time, the predetermined amplification circuit 56 is provided. By securing the gain of the above, compared with the case where the attenuator 53 of the embodiment of FIG. 2 is used, the above-mentioned band pass filter (not shown) on the reception port 12r side of the antenna sharing circuit 12 is used. ), The cutoff characteristic in the transmission band can be further relaxed, as a result, the insertion loss in the reception band can be further reduced, the reception sensitivity can be improved, and the influence of the leaked transmission signal STL can be eliminated. .

Further, by providing the band elimination filter 55, it is possible to prevent a noise signal or a spurious signal generated in the transmission circuit 40 from flowing into the reception circuit 20.

As shown in FIG. 9, a variable gain amplifying circuit 56B is provided instead of the amplifying circuit 56, and the microcomputer 32 controls the gain of the variable gain amplifying circuit 56B as shown in FIG. It can also be configured.

Also in this case, similarly to the example of FIG. 3 described above,
By controlling the gain of the variable gain amplifier circuit 56B by the microcomputer 32 so as to correct the frequency characteristic of the leakage transmission signal STL according to the transmission signal frequency,
In the transmission band BTX, the cancellation characteristic can be improved, and the directional coupler 51, the shared circuit 12, and the directional coupler 52 can be controlled by the microcomputer 32 that has been subjected to the gain adjustment operation of the user through the user interface (not shown). The offset characteristic can be improved by controlling the gain of the variable gain amplifier circuit 56B so as to correct the individual variation and the individual variation of the leakage cancellation signal generation circuit 50B.

[0070]

As described above, according to the present invention, it is possible to eliminate the influence of the leaked transmission signal leaking from the transmission circuit to the reception circuit via the antenna shared circuit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a wireless communication device according to the present invention.

FIG. 2 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 7 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 9 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 10 is a schematic diagram showing characteristics of a main part of a conventional wireless communication device.

FIG. 11 is a frequency spectrum diagram for explaining the operation of the conventional example.

[Explanation of symbols]

11 ... Antenna, 12 ... Antenna shared circuit (duplexer), 12a ... Antenna port, 12r ... Reception port,
12t ... Transmission port, 20 ... Reception circuit, 21 ... Amplification circuit, 25 ... Demodulation circuit, 31 ... Baseband signal processing circuit, 32 ... Microcomputer, 40 ... Transmission circuit, 4
DESCRIPTION OF SYMBOLS 1 ... Modulation circuit, 44 ... Drive amplification circuit, 45 ... Power amplification circuit, 50, 50A, 50B, 50C, 50D, 50E,
50F ... Leakage cancellation signal generation circuit, 51, 52 ... Directional coupler, 53 ... Attenuator, 54 ... Phase shift circuit, 55 ... Band elimination filter, 56 ... Amplification circuit, 56A, 56B ... Variable gain amplification circuit, STL ... Leaked transmission signal

Claims (8)

[Claims] 1. A transmission circuit for transmitting a transmission signal in a first frequency band, a reception circuit for receiving and processing a reception signal in a second frequency band, a transmission / reception antenna, the transmission circuit and the reception circuit, An antenna shared circuit provided between the transmitting / receiving antenna, an extracting unit for extracting a part of a transmission signal of the transmitting circuit, an amplitude and a phase of the signal extracted by the extracting unit, and the transmitting circuit From the cancellation signal generation means for generating a cancellation signal for canceling the leakage component of the transmission signal leaking to the reception circuit through the antenna shared circuit, and an injection means for injecting the cancellation signal into the reception circuit. A wireless communication device comprising: 2. The wireless communication device according to claim 1, wherein the canceling signal generating means includes an attenuator and a phase shift circuit. 3. The wireless communication device according to claim 1, wherein the canceling signal generating means includes an attenuator and a phase shift circuit, and a filter for removing components other than the transmission signal component. . 4. The wireless communication device according to claim 1, wherein the canceling signal generating means includes an amplifier circuit and a phase shift circuit. 5. The wireless communication device according to claim 1, wherein the canceling signal generating means includes an amplifier circuit, a phase shift circuit, and a filter for removing components other than the transmission signal component. . 6. The wireless communication device according to claim 1, wherein the canceling signal generating means includes a variable phase shift circuit and a variable attenuator or a variable gain amplifying circuit. 7. The wireless communication device according to claim 1, wherein the extraction means is provided on an input side of a final stage amplifier circuit of the transmission circuit. 8. The wireless communication apparatus according to claim 1, wherein the injection unit is provided on an output side of the low noise amplification circuit of the reception circuit.