JP3119963B2 - Wireless communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone or a cordless telephone in which an antenna is connected to a power amplifier for transmission and a high-frequency amplifier for reception via a duplexer, and communication is performed using different frequencies for transmission and reception. And the like.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a configuration of a peripheral portion of an antenna of a conventional radio communication apparatus. In the figure, reference numeral 1 denotes an antenna shared by transmission and reception, 2 denotes a transmission power amplifier for amplifying the power of a transmission signal transmitted from the antenna 1, and 3 denotes a reception power received by the antenna 1. This is a receiving high-frequency amplifier that performs high-frequency amplification of a signal. Reference numeral 4 denotes a duplexer which guides a transmission signal, which has been power-amplified by the power amplifier 2, to the antenna 1, and guides a reception signal received by the antenna 1 to the high frequency amplifier 3.

Next, the operation will be described. In the following description, a case where the reception frequency f _RX is higher than the transmission frequency f _TX will be described.

When this radio communication apparatus is communicating, an interference signal having a frequency of f _TX −Δf (here, Δf is a difference between the reception frequency f _RX and the transmission frequency f _TX ) is received by the antenna 1. In this case, as shown in FIG. 8, a frequency f _RX equal to the reception frequency is generated as an intermodulation (hereinafter referred to as IM) component of the power amplifier 2 for transmission, and a spurious response is generated in the receiver of the wireless communication device. I do.

Conventionally, in order to avoid occurrence of such spurious response in the receiving section of the radio communication apparatus, the transmitting side of the duplexer 4 has a band-pass configuration, or as shown in FIG. By arranging the isolator 5 between the duplexers 4,
The interference signal having a frequency of f _TX −Δf is prevented from being transmitted to the power amplifier 2.

[0006]

Since the conventional wireless communication apparatus is configured as described above, in order to avoid a spurious response of the receiver which occurs when an interference signal of the frequency f _TX -Δf is received, When the duplexer 4 has a band-pass configuration, the shape of the duplexer 4 becomes large. When the isolator 5 is inserted, not only a space for disposing the isolator 5 is required but also a transmission wave loss is generated. As a result, there has been a problem that the wireless communication apparatus is hindered from being reduced in size, weight, and power consumption.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a spurious response of a receiver due to a transmission IM wave component without hindering downsizing, weight reduction, and low power consumption of the device. It is an object of the present invention to obtain a wireless communication device that can avoid the problem.

[0008]

According to a first aspect of the present invention, there is provided a wireless communication apparatus, comprising: a resonance element, a resonance element, and a variable capacitance element for adjusting a resonance point of the resonance element at a connection point between the power amplifier and the duplexer. Is connected to a filter including a variable voltage source, and a voltage value of a control voltage applied from the variable voltage source to the variable capacitance element is controlled by the control unit based on a command which is set from the command unit and whose contents are stored in the storage unit. Is determined by

According to a second aspect of the present invention, there is provided a wireless communication apparatus in which a filter including a resonance element and a variable capacitance element for adjusting a resonance point of the resonance element is connected to a connection point between a duplexer and a high-frequency amplifier. It is.

In a wireless communication apparatus according to a third aspect of the present invention, an instruction for determining a control voltage is set by an external input through serial communication.

[0011]

According to the first aspect of the present invention, the variable voltage source is a command which is set by a command unit in a variable capacitance element of a filter connected to a connection point between a power amplifier and a duplexer and whose contents are stored in a storage unit. By adjusting the resonance point of the resonance element of the filter by applying a control voltage of a voltage value determined by the control of the control unit based on the above, without impeding the reduction in size, weight, and power consumption of the device. And a wireless communication device capable of avoiding a spurious response in the receiver.

In the wireless communication apparatus according to the second aspect of the present invention, a filter whose resonance point is adjusted by a variable capacitance element is connected to a connection point between a duplexer and a high-frequency amplifier, so that the frequency f _RX It is possible to cope with a case where a signal causing a spurious response is in the reception band.

According to a third aspect of the present invention, in the wireless communication apparatus, a command for determining a control voltage is externally input by serial communication, thereby automating setting of a command for adjusting a resonance point of a filter. Make it possible.

[0014]

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an antenna, 2 is a power amplifier for transmission, 3 is a high-frequency amplifier for reception, 4
Denotes a duplexer, which is the same as or a part equivalent to the conventional one denoted by the same reference numeral in FIG.

Reference numeral 6 denotes a filter connected to a connection point between the power amplifier 2 and the duplexer 4, reference numeral 7 denotes a resonance element such as a dielectric resonator constituting the filter 6, and reference numerals 8 and 9 denote fixed components. The capacitor 10 is an inductor. Reference numeral 11 denotes a variable capacitance element such as a varicap that finely adjusts the resonance point of the resonance element 7 by changing the value of the capacitance according to the voltage applied to the electrode.

Further, reference numeral 12 denotes a variable voltage source for generating a control voltage to be applied to the variable capacitance element 11 of the filter 6.
D / A converters that 13, the D / A converter
This is a resistor for applying the control voltage output from the variable resistor 12 to the variable capacitance element 11 via the inductor 10. 14 is this D
A CPU as a control unit for controlling the voltage value of the control voltage output from the A / A converter 12;
Reference numeral 4 denotes a keypad as an instruction unit for setting an instruction for controlling the D / A converter 12, and reference numeral 16 denotes a storage unit for storing the contents of the instruction set by the keypad 15. Note that the CPU 14, the keypad 15, the storage unit 16, and the like commonly used in the wireless communication device are used.

Next, the operation will be described. Filter 6
Is a fixed capacitor 8 in which the resonance element 7 is connected in series.
The variable capacitance element 11 is connected in parallel to form a band elimination filter, and the non-passing area is determined by the fixed capacitor 8 and the resonance point of the resonance element 7 that changes according to the capacitance value of the variable capacitance element 11. Therefore,
If the capacitance is controlled by changing the control voltage applied between the electrodes of the variable capacitance element 11, it is possible to form a band elimination filter for an interference wave f _TX −Δf for an arbitrary transmission frequency f _TX . it can. As a result, even when an interference wave having a frequency of f _TX −Δf is received by the antenna 1, a component of the frequency wave f _RT is not generated as an IM component of the power amplifier 2, and a spurious response on the receiver side is avoided. It becomes possible.

The contents of the command set for each channel by the keypad 15 are stored in the storage unit 16 in advance. The CPU 14 reads the contents of the command corresponding to the channel from the storage unit 16 and sends digital data indicating the voltage value of the control voltage to be output to the D / A converter 12. The D / A converter 12 converts the received digital data into an analog voltage, which is applied as a control voltage from the resistor 13 to the variable capacitance element 11 via the inductor 10. Here, the D / A converter 12
When an 8-bit configuration is used as the CPU 14 and the effective applied voltage of the variable capacitance element 11 is V, V
The voltage applied to the variable capacitance element 11 can be variably controlled in / 256 steps.

Next, a method of setting the command in the storage unit 16 will be described. Here, when the filter 6 is incorporated in the housing of the wireless communication device, the resonance point may change depending on whether or not the shield member is present at an adjacent location, and thus the filter 6 is the same as when the wireless communication device is used. It is necessary to set the instruction under the condition of FIG. 3 is a block diagram showing a method of setting the command. In the figure, reference numeral 20 denotes a signal generator for generating a signal wave for each channel, and reference numeral 21 denotes a signal generator for generating an interference wave. Reference numeral 22 denotes these signal generators 20 and 2
1 is a combiner that combines the outputs of the two.
A circulator 24 connected to 2 is a watt meter branched and connected by the circulator 23. Reference numeral 25 denotes an attenuator connected to the circulator 23, reference numeral 26 denotes the wireless communication device connected to the attenuator 25, and reference numeral 27 denotes a signal plus noise plus distortion versus noise which measures the amount of spurious response of the wireless communication device 26. It is a positive strain ratio meter (hereinafter referred to as a SINAD meter).

First, a signal having a frequency f _RX is generated by the signal generator 20, and an interference wave having a frequency f _TX -Δf is generated by the signal generator 21. These signals and jammers are
2 and are input to the wireless communication device 26 via the circulator 23 and the attenuator 25. Wireless communication device 26
Then, while changing the command set from the keypad 15, the amount of the spurious response is measured by the SIDA meter 27 each time, and the content of the command when the spurious response is minimized is stored in the storage unit 16. Such an operation is performed for each channel, and the contents of the instruction for minimizing the spurious response for all the channels are stored in the storage unit 16.
Set to each.

Embodiment 2 FIG. In the first embodiment, the case where the filter 6 is connected to the connection point between the power amplifier 2 for transmission and the duplexer 4 is described. However, the filter 6 is connected to the connection point between the duplexer 4 and the high-frequency amplifier 3 for reception. You may do so. FIG. 4 is a block diagram showing one embodiment of such an invention described in claim 2. The same reference numerals as in the first embodiment shown in FIG. 1 denote the respective parts, and a description thereof will be omitted. I do. As described above, by connecting the filter 4 to the connection point between the duplexer 4 and the high-frequency amplifier 3 for reception, in the receiver of the wireless communication apparatus,
It is possible to cope with a case where a signal causing a spurious response of the frequency f _RX is in the reception band in the same manner as in the first embodiment.

Embodiment 3 FIG. Further, in each of the above embodiments, the setting of the command is performed by the keypad 15.
Although a description has been given of the operation to be performed, the setting may be externally performed by serial communication. FIG. 5 is a block diagram showing an embodiment of such an invention as set forth in claim 3. In the drawing, reference numeral 17 denotes a command for the CPU 14 as a control unit to control the D / A converter 12 as a variable voltage source. This is an interface unit that functions as a command unit for setting the command. The command is input to the CPU 14 through an interface input from outside via serial communication. Therefore, the signal transmitted serially from the outside is
The command unit (interface unit) 17 may be a simple connector as long as the command unit 14 can process the command.

As described above, when an instruction can be set by external serial communication, the storage of the contents of the instruction in the storage unit 16 can be automated. FIG. 6 is a block diagram showing a method for automatically setting an instruction. In the figure, reference numeral 28 denotes a personal computer (hereinafter referred to as a personal computer) for automatically setting an instruction. Note that, in FIG. 6, the devices illustrated in FIG. 3 that are connected to the wireless communication device 26 via an attenuator are not illustrated.

Also in this case, a composite signal of the signal of the frequency f _RX and the interference wave of the frequency f _TX −Δf is input to the radio communication device 26 for each channel. Then, the personal computer 28 sends a command to be set to the interface unit 17 of the wireless communication device 26 by serial communication, and changes the SID while changing the command.
The amount of spurious response measured by the AN meter 27 is read. The personal computer 28 instructs the CPU 14 of the wireless communication device 26 to cause the storage unit 16 to store the content of the command when the spurious response is minimized. Such an operation is performed for each channel, and the contents of the command for minimizing the spurious response are automatically set in the storage unit 16 for all the channels.

[0025]

As described above, according to the first aspect of the present invention, the contents of the variable capacitance element of the filter connected to the connection point between the power amplifier and the duplexer are set by the instruction section and the contents are stored in the storage section. The control voltage of the voltage value determined based on the command stored in the filter is applied to adjust the resonance point of the resonance element of the filter, so that the device can be reduced in size, weight, and power consumption. There is an effect that a wireless communication device capable of avoiding a spurious response in the receiver without obstruction is obtained.

According to the second aspect of the present invention, since the filter in which the resonance point of the resonance element is adjusted by the variable capacitance element is connected to the connection point between the duplexer and the high-frequency amplifier, the frequency f _RX This has an effect that it is possible to cope with a case where a signal causing the spurious response is within the reception band.

According to the third aspect of the present invention, since the command for adjusting the resonance point of the filter is externally input by serial communication, the setting of the command is automatically performed by a personal computer or the like. There is an effect that can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main part of a wireless communication device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing characteristics of a filter in the embodiment.

FIG. 3 is a block diagram for explaining an instruction setting method in the embodiment.

FIG. 4 is a block diagram illustrating a main part of a wireless communication device according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a main part of a wireless communication device according to a third embodiment of the present invention.

FIG. 6 is a block diagram for explaining an instruction setting method in the embodiment.

FIG. 7 is a block diagram showing a main part of a conventional wireless communication device.

FIG. 8 is an explanatory diagram showing a transmission IM component of a conventional wireless communication device.

FIG. 9 is a block diagram showing a main part of another conventional wireless communication device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Antenna 2 Power amplifier 3 High frequency amplifier 4 Duplexer 6 Filter 7 Resonant element 11 Variable capacitance element 12 Variable voltage source ( D / A converter ) 14 Control part (CPU) 15 Command part (keypad) 16 Storage part 17 Command part (interface) Part)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/38-1/58

Claims (3)

(57) [Claims] 1. A wireless communication device in which a transmitting power amplifier and a receiving high-frequency amplifier are connected to an antenna shared by transmitting and receiving via a duplexer, and communication using different frequencies is performed for transmitting and receiving. Connecting a resonance element to a connection point between the power amplifier and the duplexer and a filter having a variable capacitance element whose capacitance changes according to an applied voltage and adjusts a resonance point of the resonance element. A variable voltage source that generates a control voltage to be applied to the variable capacitance element of the filter, a control unit that controls a value of the control voltage output by the variable voltage source, and a control unit that controls the variable voltage source. A wireless communication device comprising: an instruction unit for setting an instruction; and a storage unit for storing the content of the instruction set by the instruction unit. 2. A wireless communication apparatus in which a transmitting power amplifier and a receiving high-frequency amplifier are connected via a duplexer to an antenna shared by transmitting and receiving and using different frequencies for transmitting and receiving. A resonance element is connected to a connection point between the duplexer and the high-frequency amplifier, and a filter having a variable capacitance element whose capacitance changes according to an applied voltage to adjust the resonance point of the resonance element is connected. A variable voltage source that generates a control voltage to be applied to the variable capacitance element of the filter, a control unit that controls a value of the control voltage output by the variable voltage source, and a control unit that controls the variable voltage source. A wireless communication device comprising: an instruction unit for setting an instruction; and a storage unit for storing the content of the instruction set by the instruction unit. 3. The wireless communication apparatus according to claim 1, wherein the command unit is an interface unit that interfaces a command input through serial communication from outside and inputs the command to the control unit. .