JPH0983398A - Radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce transmission loss and to shorten manufacturing time by changing the impedance of first and second impedance variable element parts so that an intermediate frequency signal may be the largest. SOLUTION: At the time as a normal operation, the data showing the size of an inputted IF signal is transmitted as RSSI(Receive Signal Strength Indicator) data to a microcomputer 13, in an IF(interface) circuit 5. The microcomputer 13 grasps the transmitted RSSI data value, changes the control data to D/A conversion circuits 10 and 12 so that this value is max. and changes bias voltage to be inputted to impedance variable elements 8 and 9. Thus, the impedance of the impedance variable elements 8 and 9 themselves is changed, a RF(radio frequency) circuit 2 is corrected to the state that transmission loss in min. and reception quality is improved.

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, and more particularly to adjustment of impedance between elements in a high frequency circuit section.

[0002]

2. Description of the Related Art As a conventional example 1 of this type, JP-A-61-161
There is one disclosed in Japanese Patent No. 41212, and the details of the present invention will be given to this publication, but the essential points will be briefly described below.

First, the monolithic amplifier circuit disclosed in the above publication includes an amplifier circuit including a semiconductor active element, and an input-side impedance conversion circuit including an impedance element provided on the input side of the amplifier circuit. , And an output side impedance conversion circuit provided on the output side, and a Schottky barrier diode type voltage variable capacitance element is used for the input side impedance conversion circuit and the output side impedance conversion circuit.

Therefore, by applying a control voltage from the outside to the Schottky barrier diode type voltage variable capacitance element and adjusting the capacitance value, the impedance seen from the amplification side of the input side impedance conversion circuit and the output side impedance conversion circuit is The adjustment is performed so that the characteristics suitable for the characteristics of the semiconductor active element used in the amplifier circuit can be obtained.

As a second conventional example, FIG. 2 is a block diagram of a high frequency circuit section of a wireless communication device, and FIG. 3 is a perspective view of a substrate of the high frequency circuit section. In the figure, 1 is an antenna,
Reference numeral 2 denotes an RF (radio f) that converts a signal received by the antenna 1 into an intermediate frequency signal (hereinafter referred to as an IF signal).
frequency) circuit, 3 is a surface acoustic wave filter (hereinafter referred to as SAW filter), 4 is an RF circuit 2 and SAW
It is a matching circuit that adjusts the matching of the impedance of the filter 4.

Reference numeral 5 is an interface circuit (hereinafter referred to as IF circuit) for converting an intermediate frequency signal into a baseband signal, 6 is a matching circuit for adjusting impedance matching between the SAW filter 4 and the IF circuit 5, and 7 is a local. A local oscillator that gives a frequency to the RF circuit 2 is a trimmer capacitor (variable capacitor) 8 that forms a part of the matching circuits 4 and 6.

Next, the operation will be described. The high frequency signal received by the antenna 1 is amplified in the RF circuit 2 and mixed inside the circuit using the local frequency from the local oscillator 7 and output as an IF signal. After that, unnecessary power is removed from the IF signal by the SAW filter 3, and the IF signal is sent to the IF circuit 6. The IF circuit 6 further converts the signal to a low frequency, demodulates it into a baseband signal, and sends it to a baseband IC (not shown).

Although the above is the normal operation, matching of the impedance of the circuit will be described here. In order for the IF signal output from the RF circuit 2 to be transmitted to the IF circuit 5 without loss, the impedances between the RF circuit 2 and the SAW filter 3 and between the SAW filter 3 and the IF circuit 5 are set by the matching circuits 4 and 6. It is necessary to adjust the matching to the best condition with less transmission loss. Therefore, the trimmer condenser 8 or the like is used, and the knob of the trimmer condenser 8 itself is rotated and mechanically adjusted.

[0009]

Since the conventional radio communication device is configured as described above, in the prior art example 1, a control voltage is externally applied to the Schottky barrier diode type voltage variable capacitance element, and the capacitance thereof is increased. The impedance must be adjusted for each individual monolithic amplifier circuit in order to adjust the value and obtain the characteristics that match the characteristics of the semiconductor active element used in that amplifier circuit, which is very troublesome. There was a problem that was.

In the conventional example 2, in order to adjust the impedance matching, it is necessary to mechanically adjust the trimmer capacitors 8 and the like for each unit, so that the manufacturing efficiency is low, that is, the automation of the assembly process. However, this matching adjustment process must be performed by a person, and the non-automation of this part of the process reduces the efficiency of the entire manufacturing process.

The present invention has been made in order to solve the above-mentioned problems, and can automatically adjust the impedance, have a good impedance matching, have a high-frequency circuit section with less transmission loss, and reduce the manufacturing time. An object of the present invention is to obtain a wireless communication device that can be shortened.

[0012]

A radio communication apparatus according to the present invention includes an antenna, a high frequency circuit section for converting a signal received by the antenna into an intermediate frequency signal, and a high frequency circuit section for converting the intermediate frequency signal into a baseband signal. Interface circuit section for converting into a high-frequency circuit section, a filter circuit section connected between the interface circuit section and the high-frequency circuit section, and a first impedance variable inserted between the filter circuit section and the high-frequency circuit section. An element section, a second impedance variable element section inserted between the filter circuit section and the interface circuit section, and a control for changing impedance to the first impedance variable element section and the second impedance variable element section And a control unit for outputting a signal, and the control unit inputs the intermediate frequency signal to the interface circuit unit. Of detecting the size, thereby changing the first variable impedance element and the impedance of the second variable impedance element as the intermediate frequency signal is maximized.

Further, the control section is provided with a storage section for storing control signal values to the first variable impedance element section and the second variable impedance element section when the intermediate frequency signal by the control section is maximized. The control signal value stored in is output to the first variable impedance element section and the second variable impedance element section.

Further, a baseband circuit unit for demodulating the baseband signal by the interface circuit into voice is provided, and the control unit detects the bit error rate of the baseband signal demodulated into voice by the baseband circuit unit and detects this bit error. The impedances of the first variable impedance element section and the second variable impedance element section are changed so that the ratio becomes the smallest.

Further, the control section is provided with a storage section for storing control signal values to the first variable impedance element section and the second variable impedance element section when the bit error rate by the control section is minimized. The control signal value stored in is output to the first variable impedance element section and the second variable impedance element section.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. FIG. 1 is a block diagram of a high-frequency circuit section of a wireless communication device showing an embodiment of the present invention. In the figure, the same or corresponding parts as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. 8 and 9 are variable impedance elements, 1
Reference numerals 0 and 11 are D / A conversion circuits, 12 is a baseband circuit that demodulates the baseband signal from the IF circuit 5 into voice, and 1
Reference numeral 3 is a microcomputer for controlling the entire circuit, and 14 is a memory for storing data input to the D / A conversion circuits 10 and 11.

Next, the operation will be described. The high frequency signal received by the antenna 1 is amplified in the RF circuit 2 and mixed inside the circuit using the local frequency from the local oscillator 7 and output as an IF signal. Thereafter, the SAW filter 3 removes unnecessary power from the IF signal, and the IF signal is sent to the IF circuit 5. The IF circuit 5 further converts the signal to a low frequency, demodulates it into a baseband signal, and transmits it to the baseband circuit 12.

The above is the normal operation, and the impedance matching of the circuit will be described here. At the same time as the above-mentioned normal operation, in the IF circuit 5, data indicating the magnitude of the input IF signal is sent to the RSSI (Receive).
Signal Strength Indicato
r) The data is transmitted to the microcomputer 13. Therefore,
The microcomputer 13 grasps the transmitted RSSI data value, and the D / A conversion circuit 1 determines that this value becomes the largest.
The control data for 0 and 12 are changed, and the bias voltage input to the variable impedance elements 8 and 9 is changed. As a result, the impedances of the variable impedance elements 8 and 9 themselves are changed, and the RF circuit 2 can be corrected to the state where the transmission loss is the minimum, and the reception quality is improved.

Further, if the impedance is adjusted based on the RSSI data every time the antenna 1 actually receives a high frequency signal, the processing speed of the entire wireless communication device will be slowed down, so the RSSI in the manufacturing process of the wireless communication device will be reduced.
The control data at the time of completion of correction by the data is stored in the memory 14, and the microcomputer 13 reads the control data from the memory 14 at the time of actual use, and immediately D / A
It is input to the conversion circuits 10 and 12 and the impedances of the variable impedance elements 8 and 9 themselves are corrected to the state where the transmission loss is the smallest. This allows impedance adjustment without slowing down the processing speed of the entire wireless communication device.

Embodiment 2. In the first embodiment, I
The impedance was adjusted using the RSSI data in the F circuit 5, but the ratio of erroneous bits included in the received data of the baseband signal demodulated into voice in the baseband circuit 12, that is, the bit error rate (bit error rate). ) May be used.

At the same time as the normal operation described in the first embodiment,
In the baseband circuit 12, the bit error rate of the baseband signal demodulated into voice is transmitted to the microcomputer 13. Therefore, the microcomputer 13 grasps the transmitted bit error rate, changes the control data to the D / A conversion circuits 10 and 12 so that this value becomes the minimum, and inputs the bias to the variable impedance elements 8 and 9. Change the voltage. As a result, the impedances of the variable impedance elements 8 and 9 themselves are changed, and the RF circuit 2 can be corrected to the state where the transmission loss is the minimum, and the reception quality is improved.

Further, similar to the first embodiment, the control data at the time of completion of correction by the bit error rate in the manufacturing process of the wireless communication device is stored in the memory 14, and the microcomputer 13 reads the control data from the memory 14 at the time of actual use, Instantly D / A conversion circuits 10 and 12
Input to the impedance variable elements 8 and 9 and corrects the impedance of the impedance variable elements 8 and 9 themselves to a state where the transmission loss is the smallest. This allows impedance adjustment without slowing down the processing speed of the entire wireless communication device.

[0023]

As described above, according to the present invention, the control unit detects the magnitude of the intermediate frequency signal input to the interface circuit unit, and the first intermediate frequency signal is detected so as to be the largest. Impedance variable element section and second
Since the impedance of the variable impedance element part of is changed, the impedance matching between each circuit can be automatically adjusted, the high frequency circuit part with less transmission loss is provided, the reception quality can be improved, and the manufacturing time can be shortened. There is an effect that it is possible to obtain a wireless communication device that can be shortened and improve manufacturing efficiency.

Further, since the control section outputs the control signal value stored in the storage section to the first variable impedance element section and the second variable impedance element section, impedance matching between the respective circuits can be performed immediately. It is possible to obtain a wireless communication device that can be automatically adjusted and that can perform impedance adjustment without slowing down the processing speed of the entire device.

Further, the control section detects the bit error rate of the baseband signal demodulated into voice in the baseband circuit section, and the first impedance variable element section and the second impedance variable element section are arranged so that this bit error rate becomes the smallest. Since the impedance of the variable impedance element part is changed, impedance matching between circuits can be automatically adjusted, and a high-frequency circuit part with less transmission loss can be provided to improve reception quality and reduce manufacturing time. Then, there is an effect that a wireless communication device capable of improving manufacturing efficiency can be obtained.

Further, the control section is provided with a storage section for storing control signal values to the first impedance variable element section and the second impedance variable element section when the bit error rate by the control section is minimized. Since the control signal value stored in is output to the first impedance variable element section and the second impedance variable element section, the impedance matching between the circuits can be immediately and automatically adjusted, and the entire apparatus can be adjusted. There is an effect that a wireless communication device capable of impedance adjustment can be obtained without slowing down the processing speed.

[Brief description of drawings]

FIG. 1 is a block diagram of a high frequency circuit section of a wireless communication device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional high frequency circuit unit.

FIG. 3 is a perspective view of a substrate of a high frequency circuit section of a conventional wireless communication device.

[Explanation of symbols]

1 antenna, 2 RF circuit, 3 surface acoustic wave filter, 5 interface circuit, 8 impedance variable element, 9 impedance variable element, 10 D / A conversion circuit, 11 D / A conversion circuit, 12 baseband circuit, 13 microcomputer, 14 memory

Claims (4)

[Claims] 1. An antenna, a high frequency circuit section for converting a signal received by the antenna into an intermediate frequency signal, an interface circuit section for converting the intermediate frequency signal by the high frequency circuit section into a baseband signal, and the interface circuit section. A filter circuit section connected between the face circuit section and the high-frequency circuit section; a first impedance variable element section inserted between the filter circuit section and the high-frequency circuit section; the filter circuit section and the interface; A second impedance variable element section inserted between the face circuit sections, and a control section for outputting a control signal for changing the impedance to the first impedance variable element section and the second impedance variable element section. The control unit controls the magnitude of the intermediate frequency signal input to the interface circuit unit. Knowledge and, a radio communication apparatus characterized by changing the first variable impedance element and the impedance of the second variable impedance element as the intermediate frequency signal is maximized. 2. A storage unit that stores a control signal value to the first impedance variable element unit and the second impedance variable element unit when the intermediate frequency signal by the control unit is maximized, 2. The wireless communication device according to claim 1, wherein the unit outputs the control signal value stored in the storage unit to the first impedance variable element unit and the second impedance variable element unit. 3. An antenna, a high frequency circuit section for converting a signal received by the antenna into an intermediate frequency signal, an interface circuit section for converting the intermediate frequency signal by the high frequency circuit section into a base band signal, and an interface circuit for the interface circuit section. A baseband circuit section for demodulating a baseband signal into voice by means of; a filter circuit section connected between the interface circuit section and the high-frequency circuit section; and a filter circuit section inserted between the filter circuit section and the high-frequency circuit section. A first impedance variable element section, a second impedance variable element section inserted between the filter circuit section and the interface circuit section, the first impedance variable element section and the second impedance variable element section. Control unit that outputs a control signal that changes the impedance to the variable impedance element unit The control unit detects a bit error rate of a baseband signal demodulated into speech by the baseband circuit unit, and the first impedance variable element unit and the first impedance variable element unit are configured to minimize the bit error rate. 2. A wireless communication device characterized in that the impedance part of the variable impedance element 2 is changed. 4. A storage unit that stores a control signal value to the first impedance variable element unit and the second impedance variable element unit when the bit error rate by the control unit is minimized, 4. The wireless communication device according to claim 3, wherein the unit outputs the control signal value stored in the storage unit to the first impedance variable element unit and the second impedance variable element unit.