JPH0310521A - Antenna tuner - Google Patents

Abstract

PURPOSE:To attain quick matching when a frequency band is changed by storing reference information to each frequency band as a table, reading the reference information with respect to the designated frequency band, and supplying the result to a matching circuit as a preset signal. CONSTITUTION:A microcomputer 10 is backed up by a battery and a reference voltage data with respect to a frequency band data is stored in a RAM as a data table. When the frequency band designation data is changed, the reference voltage data to the driving position of 1st and 2nd motors to the frequency designation data is retrieved from the data table and the retrieved reference voltage data is supplied to a D/A converter 18. A travelling wave detection output voltage and a reflecting wave detection output voltage converted by an A/D converter 11 are read to calculate the voltage standing wave ratio(VSWR) thereby applying the control.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an antenna tuner that is located between a transmitter and an antenna and performs impedance matching.

(Prior art) A conventional antenna tuner detects a traveling wave as shown in FIG. 4, detects the detected output voltage and reflected wave,
The input signal is guided to the traveling wave detection output/reflected wave detection output voltage detection circuit 1 that detects the detection output voltage, and the detected detection output voltage is supplied to the standing wave ratio calculation circuit 4 to calculate the standing wave ratio. , and is supplied to a speed control signal generation circuit 7 which determines matching from the calculated standing wave ratio and outputs a speed control signal. on the other hand,
Traveling wave detection output/Reflected wave detection output The transmission power signal via the voltage detection circuit is supplied to the voltage/current detection circuit 2 to detect the voltage and current components, and the detected voltage and current components are subjected to matching control. A rotation direction control signal is supplied to the motor control circuit 6 and outputted from the speed control signal generation circuit 7. A speed control signal corresponding to the standing wave ratio is also supplied to the motor control circuit 6, and the first and second motors are driven and matched by the signal supplied to the motor control circuit 6. The matching control signal includes a rotation direction control signal for the first motor to make the phase difference zero, a rotation direction control signal for the second motor to make the amplitude difference zero, and the first motor rotation direction control signal to make the amplitude difference zero.
and a speed control signal output from the speed control signal generation circuit 7 to control the speed of the second motor.

(Problems to be Solved by the Invention) In the conventional antenna tuner as described above, after matching, if the frequency band is changed, the matching state changes, so it is necessary to readjust the matching, which delays the timing of transmission. There was also a problem.

Another problem is that if the best condition cannot be found depending on the condition of the antenna, matching will not be completed for a long time.

The purpose of this invention is to solve the above-mentioned problems and provide an antenna tuner that can accurately calculate the standing wave ratio, can quickly match even when changing frequency bands, and can quickly complete matching. shall be.

(Means for Solving the Problems) An antenna tuner of the present invention is located between a transmitter and an antenna of a communication device and detects a signal corresponding to a traveling wave of a transmitted wave and a signal corresponding to a reflected wave, and detects a signal corresponding to a traveling wave of a transmitted wave and a signal corresponding to a reflected wave. As shown in FIG. 1, in an antenna tuner that performs matching to minimize matching, a storage means 22 stores reference data as a table to be supplied to the matching means 21 of the antenna tuner for each transmission frequency band; a specifying means 23 for specifying a frequency band; a search means 24 for searching the storage means 22 for reference data for the transmission frequency band specified by the item determining means 23; and a signal corresponding to the reference data searched by the search means 24. The present invention is characterized in that it includes a preset means 25 for briscenting the information to the matching means 21.

(Operation) In the present invention having the above configuration, when a transmission frequency band is specified by the specifying means 23, the search means 24 searches the storage means 22 for reference data for the specified frequency band. A signal corresponding to the retrieved reference data is preset from the presetting means 25 to the matching means 21. Because of the signal corresponding to the precented reference data, the period until matching is achieved when the transmission frequency band is switched is shortened.

(Example) This invention will be explained below with reference to Examples.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and the same components as those of the conventional example shown in FIG. 4 are given the same reference numerals, and the explanation thereof will be omitted.

The traveling wave detection output voltage and the reflected wave detection output voltage output from the traveling wave detection output/reflected wave detection output voltage detection circuit 1 are converted into digital data by an A/D converter 11. The matching circuit 3 is configured to achieve matching by changing the capacitance of a variable capacitor, for example, and the capacitance of the variable capacitor is changed by rotationally driving a motor connected to a drive shaft of the variable capacitor. . The rotation angle of this motor is detected by an angle detector 16 consisting of a volume, and the detected angle signal is supplied to an A/D converter 17 and converted into digital data. The digital data converted by the A/D converter 11, the digital data converted by the A/D converter 17, the frequency band designation data, and the matching start instruction signal are supplied to the microcomputer 10.

The microcomputer 10 includes a RAM that is backed up by a battery and constitutes a part of the microcomputer IO, and reference voltage data for frequency band data is stored in advance in the RAM as a data table. The reference voltage data output from the microprocessor 1o or the detection data from the angle detector 16 is supplied to the D/A converter 18 and converted into an analog voltage. This voltage is supplied as a reference voltage to the angle control comparator 14 consisting of the following. On the other hand, the output voltage from the variable voltage source 12 is also
3, and by switching the changeover switch 13, the output voltage from the variable voltage source 12 is supplied to the angle control comparator 14 as a reference voltage instead of the analog voltage from the D/A converter 18.

The detected angle signal output from the angle detector 16 is supplied to the angle control comparator 14 as a comparison voltage, and the angle control comparator 14 supplies it to the control switching circuit 15. The output from the control switching circuit 15 is supplied to the matching circuit 3 via the motor control circuit 6.

The microprocessor 10 supplies a signal corresponding to the calculated standing wave ratio to the D/A converter 8, converts it into an analog voltage, and converts it into an analog voltage.
The analog voltage from the A converter 8 is supplied to a matching judgment circuit 9 consisting of a comparator, which judges matching or mismatching, and supplies the judgment output to the microcomputer 10. Further, the analog signal from the D/A converter 8 is supplied to the motor control circuit 6 as a speed control signal. The microcomputer 10 detects that the output from the A/D converter 17 has reached a predetermined value, detects that the slider position of the volume forming the angle detector 16 has reached a predetermined position, and switches control. circuit 15
Outputs a control switching signal to

The operation of this embodiment configured as described above will be explained with reference to FIG.

When the program is started, it is checked whether the frequency band designation data has been changed (step S1), and if it is determined in step S1 that the frequency band designation data has been changed, the rotational positions of the first and second motors with respect to the frequency designation data are checked. Reference voltage data for the reference voltage is retrieved from the data table, and the retrieved reference voltage data is supplied to the D/A converter 18. As a result, the reference voltage data is converted into an analog voltage. Also, the angle control comparator 1
A control signal is output for switching the control switching circuit 15 so that the output from the matching control circuit 4 is supplied to the motor control circuit 6 instead of the output from the matching control circuit 15 (step St).

By executing step S2, the first and second motors are controlled to positions corresponding to the reference voltage data (step S). In FIG. 3, it is labeled as a variable capacitor set. Steps S and -S3 are preset tuning states. Following step S3, a check is made to determine whether or not an instruction to start alignment has been given, and a wait is made for an instruction to start alignment (
Step S,). When it is determined in step Sl that the frequency band designation data has not been changed, step S is executed subsequent to step S.

When it is determined in step S4 that a matching start instruction has been issued, the traveling wave detection output voltage and the reflected wave detection output voltage converted by the A/D converter 11 are read and stored in the RAM of the microcomputer 10. (Step S,). A standing wave ratio (VSWR) is calculated from the data stored in step S, and the calculated standing wave ratio is stored in the RAM (step S6). Following step S6, the outputs for the first and second volume positions from the angle detection circuit 16 are sent to the A/D converter 17 as digital data POD1.
．． It is converted into POD2 and stored in RAM (step S).

data PODI is added to the first polyneme, data POD2
corresponds to the second volume.

Following step S7, it is checked whether the digital data PODI converted in step S is less than the value (■1) for the voltage when the first volume that constitutes the angle detection circuit 16 reaches the left end position. and if it is determined to be less than V2, data that takes into account the inertia until the motor stops
'('=vz a) is output to the D/A converter 18 as data for the first motor, and data POD2 obtained by converting the output for the second volume position into digital data by the A/D converter 17 is output to the D/A converter 18 as data for the first motor. Data for the first and second motors is outputted to the D/A converter 18 and converted into an analog voltage as data for the second motor (steps S, , S, ), and the data for the first and second motors are output as data for the second motor (2) in the same manner as in step S2.

Drive to the position corresponding to POD2 (step S,
,). Step S and step S1° are performing pullback control.

Following step S1゜, data PODI＞■
2 (step Sz), PQDl
>V, data ■11 is data POD
I, that is, D/A as data for the first motor
The data POD2 is output to the D/A converter 18 as data for the second motor to drive the first and second motors to positions corresponding to the data V, 1 data POD2 (step S+z , 513), where the data V1' is (V, +d). d is a value corresponding to the inertia of the motor until it stops ■2
It is the same as the case of ′.

Following step Si, data PO[12<data ■.

It is checked (step S+,) whether the data PO
When it is determined that D2 <Data■1, the data POD
D/A converter 1 with I as data for the first motor.
The data 2' is outputted to the D/A converter 18 as data for the second motor, and the data
The motor is driven to the position corresponding to data PODI and data ■2 (steps SIS, S2, .).

Following step S16, data POD2 > data■
2 or not (step Sl?), and the data PO
When it is determined that D2>V, data PODI is output to the D/A converter 18 as data for the first motor, and data Vl' is output to the D/A converter 18 as data for the second motor. Then, the first and second motors are driven to the positions corresponding to the data POD2 and the data ■I1 (step S115 S19).

Here step 312 and Sll, steps SIS and Sl
&, Step SIR and Sl9 are pullback controls similar to Steps S9 and S10.

If it is determined in step S8 that PODI<V, then step S and Sl. is skipped, and when it is determined in step S that PODI > V 2 is not satisfied, steps S1□ and S13 are skipped, and in step S14, POD2 < V,
If it is determined that it is not, step SIS and step
Tube SI6 is skipped, and in step 317 P
If it is determined that OD2>V is not the case, step srs
and 319 are skipped.

As is clear from the above, the pullback control is performed using the angle detector 16.
When the slider of the volume moves to one end, it acts to return the slider to the other end.

Following step SI9, the standing wave ratio data stored in the RAM is read in step S6, and the read standing wave ratio data is output to the D/A converter 8, and at the same time, the control switching circuit 1
5 to supply the matching control signal from the matching control circuit 5 to the motor control circuit 6 (step 5zo). Following step S2, the converted analog signal in the D/A converter 8 is supplied to the motor control circuit 6 as a speed control signal,
At the same time, the first and second motor speeds are controlled, and a comparison output is read and checked to see if there is a match (step S2, ). If it is not determined in step SZI that there is a match, the process is executed again from step S5. When it is determined in step 321 that there is a match, the output from the angle detection circuit 6 is converted into digital data by the A/D converter 17 (step S2 □), and the converted data from the A/D converter 17 is used to generate the frequency. Step 5Z3) and step SI are executed to update the reference voltage data for the band.

Furthermore, when the matching state of the antenna is poor, the changeover switch 13 can be switched to supply the output voltage of the variable voltage source 12 to the angle control comparator 14 instead of the output of the D/A converter 18. In this case, by switching the changeover switch 13, the output of the angle control comparator 14 is supplied to the control switching circuit 15 instead of the output from the matching control circuit 5.

As described above, in this embodiment, the standing wave ratio is calculated by the microcomputer 10, so that the standing wave ratio can be calculated accurately using a regular calculation formula.

In addition, by storing data in the matching state when a terminator with an impedance of 50 Ω is connected in the RAM as reference voltage data at the time of factory shipment, quick matching can be achieved even when operating in the automatic matching state from the factory shipment state. becomes possible.

(Effects of the Invention) As explained above, according to the present invention, there is provided means for storing reference information for each frequency band as a table, and when a frequency band is specified, reference information for the specified frequency band is provided. Since the reference information read out is supplied as a recent signal to the matching circuit, quick matching is possible when changing the frequency band.

[Brief explanation of the drawing]

FIG. 1 is a functional diagram showing the configuration of this invention. FIG. 2 is a schematic diagram showing the configuration of an embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention. FIG. 4 is a configuration diagram of a conventional example. 1... - Traveling wave detection output/reflected wave detection output voltage detection circuit, 2... Voltage/current detection circuit, 3... Matching circuit, 5... Matching control circuit, 6... Motor control circuit , 8 and 18...D/A converter, 9...matching judgment circuit,
11 and 17...A/D converter, 12...-variable voltage source, 13...changeover switch, 14...angle control comparator, 15...control switching circuit, 16...angle detection circuit .

Claims (1)

[Claims] The antenna tuner, which is located between the transmitting section of a communication device and the antenna, detects a signal corresponding to the traveling wave of the transmitted wave and a signal corresponding to the reflected wave, and performs matching to minimize the reflected wave. a storage means storing reference data to be supplied to the matching means of the antenna tuner as a table; a specification means for specifying a transmission frequency band; and a search for reference data for the transmission frequency band specified by the specification means from the storage means. An antenna tuner comprising a search means and a preset means for presetting a signal corresponding to the reference data searched by the search means in the matching means.