JPH08195684A - Automatic matching device for antenna - Google Patents

Abstract

PURPOSE: To provide an automatic antenna matching device which can automatically match a transmitter with an antenna in a short time and by a proper operation that is performed according to the phase of input impedance of the transmitter and the state of the real resistance and also can shorten the second automatic matching time after the first matching processing. CONSTITUTION: In an initial mode, the matching processing is done in a state where a matching unit 3 is removed. A phase meter 4 measures and decides whether the phase of input impedance of an antenna 2 is inductive or capacitive. An impedance meter 5 measures and decide whether the real resistance including the unit 3 is higher or lower than the nominal impedance of a transmitter 1. A control circuit 7 properly controls L, C, K1 and K2 according to each state and sets them at the levels less than the prescribed VSWR value. Then the states of L, C, K1 and K2 are stored when the matching processing is completed. When the VSWR exceeds a prescribed level, the matching processing is started again when the first processing is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matching device used for a transmitter connected to an antenna, and more particularly to an automatic antenna matching device for automatically performing matching in a short time.

[0002]

2. Description of the Related Art If the input impedance of an antenna is not matched to the feed line (including the transmitter), reflection occurs at the feed point, and the reflected wave is reflected again on the transmitter side and disturbs the transmission signal. is there. At the same time, reflection loss occurs. Therefore, a matching device is required to match the input impedance of the antenna to the feeder line.

If the state of the antenna does not change, the constants of the matching box can be adjusted and determined at the time of setting. However, in an aerial line for ships and the like, the state of the aerial line changes due to changes in the draft and the weather, making it impossible to match the input impedance of the aerial line with the power supply line.

As a conventional technique, Japanese Patent Laid-Open No. 54-1535 is used.
No. 07, "A method of automatically matching a radio frequency transmitter with an antenna" is disclosed. This method first initializes the values of L and C at the start of automatic matching. next,
In the first stage, the input impedance of the matcher is made to have a substantial component below the nominal real impedance of the transmitter. In the second stage, the input impedance of the matcher is increased from the nominal real impedance to a predetermined range.
As a detector, a voltage standing wave ratio (VSWR: Volta) is used.
A ge standing wave ratio) meter and a phase meter are used.

A specific description will be made with reference to FIG. (A)
The operation is started assuming that the antenna (antenna) is inductive. (B) L is short-circuited and C is maximum as initial settings. As a result, the antenna becomes capacitive. (C) Increase L until inducible. (D) C until capacitive
To reduce. (E) The above (c) and (d) are repeated until it is within a predetermined VSWR, and the process is completed.

(F) When all the inductances are used during the above operation, or when the shunt capacitor becomes zero, the procedure goes to the capacitive routine. As an initial setting, L is shorted and C is open. (G) Increase L until inducible. (H) The zero cross phase is detected by increasing or decreasing C. (I) The L value in (g) above is increased by one step. (J) The operation of (h) above is performed. (K) The above (i) and (j) are repeated until it is within a predetermined VSWR, and the process is completed.

[0007]

However, JP-A-54-
According to the invention of Japanese Patent No. 153507, matching time is lengthened because automatic matching is performed by a fixed algorithm regardless of the antenna (antenna) constant. Further, even if the antenna impedance slightly changes after performing automatic matching once, the L and C values are initialized to perform automatic matching.
In the matching process, the impedance is forced to be equal to or less than the nominal actual impedance. Therefore, a matching time equal to the initial matching time is required.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an antenna automatic alignment apparatus capable of performing alignment in a short time.

[0009]

In order to solve the above-mentioned problems, the automatic antenna matching device of the invention of claim 1 and the automatic antenna matching system of the invention of claim 2 are as follows:
Processing is performed from the state in which the matching box is removed (FIG. 1A). Then, it is measured whether the phase of the antenna input impedance is inductive or capacitive, and further, whether the actual resistance is higher or lower than the nominal impedance (Z0) of the transmitter. Depending on the respective values, L, C, K1, and K2 are appropriately controlled, and a predetermined V
Keep below the SWR value.

A detailed description will be given with reference to FIG. FIG.
As shown in (b), four kinds of operations are performed depending on which quadrant of the Smith chart the impedance of the antenna is located in. Fig. 1 shows the case where the impedance of the antenna is in the quadrant of Fig. 1 (b).
This will be described in (c). First, K2 is turned on, C is increased, and the input impedance seen from the transmitter is made capacitive. The actual resistance is then the nominal impedance of the transmitter (Z
0), and the LC matching operation is performed so that the actual resistance approaches the nominal impedance (Z0). In each automatic matching process, when the value becomes equal to or lower than the predetermined VSWR value, the automatic matching ends.

The case where the impedance of the antenna is in the quadrant of FIG. 1 (b) will be described with reference to FIG. 1 (d). First,
L is increased to make the input impedance seen by the transmitter inductive. Next, it is determined that the actual resistance is higher than the nominal impedance (Z0) of the transmitter, K2 is turned on, and L is set so that the actual resistance approaches the nominal impedance (Z0).
Perform C matching operation. In each automatic matching process,
When the value becomes equal to or lower than the predetermined VSWR value, the automatic matching ends.

A case where the impedance of the antenna is in the quadrant of FIG. 1B will be described with reference to FIG. First,
L is increased to make the input impedance seen by the transmitter inductive. Next, it is determined that the actual resistance is lower than the nominal impedance (Z0) of the transmitter, K1 is turned on, and C is set so that the actual resistance approaches the nominal impedance (Z0).
Perform L matching operation. In each automatic matching process,
When the value becomes equal to or lower than the predetermined VSWR value, the automatic matching ends.

The case where the impedance of the antenna is in the quadrant of FIG. 1B will be described with reference to FIG. First,
K2 is turned on and C is increased to make the input impedance seen by the transmitter capacitive. Next, it is determined that the actual resistance is higher than the nominal impedance (Z0) of the transmitter, K1 is turned on and K2 is turned off, and the CL matching operation is performed so that the actual resistance approaches the nominal impedance (Z0). In each automatic matching process, when the value becomes equal to or lower than the predetermined VSWR value, the automatic matching ends.

In the automatic antenna alignment system of the third aspect of the present invention, the alignment operation after the alignment is completed is as follows.
Measure the state of K1 and K2 and the phase of the input impedance of the matching device at this time, and measure L or C and K until the actual resistance is reached.
1 and K2 are operated. Next, the impedance of the actual resistance is measured, and when the impedance is higher than the nominal impedance (Z0) of the transmitter, L or C is used to decrease the impedance.
To change. When it is lower than the nominal impedance (Z0) of the transmitter, L or C is changed in the direction of increasing the impedance. After that, L and C variable operation by phase detection,
The variable operation of L and C by impedance detection is repeated until the value becomes equal to or lower than a predetermined VSWR value.

[0015]

According to the antenna automatic matching device and the antenna automatic matching system configured as described above, an appropriate matching operation is performed depending on the phase of the input impedance and the actual resistance of the transmitter. Therefore, the matching time can be shortened. Also, the better the VSWR before the start of matching, the shorter the matching time. That is, the re-automatic alignment time after performing the automatic alignment once becomes short.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

[First Embodiment] (Structure) FIG. 2 is a block diagram of an automatic antenna matching device. In order to match the transmitter 1 with the antenna 2, the matching device 3
To insert. The matching unit 3 includes a variable series inductance L (hereinafter, simply referred to as “L”) for making the matching unit 3 inductive, and a variable branch capacitance C (hereinafter, simply referred to as “C”) for making the matching unit 3 capacitive. .), Variable branch capacitance coupling means K1 (hereinafter simply referred to as “K1”) for CL coupling when the actual resistance is lower than the nominal impedance of the transmitter 1, and the actual resistance is the nominal impedance of the transmitter 1. A variable branch capacitance coupling means K2 (hereinafter simply referred to as "K2") for LC coupling in the case of higher voltage. Further, between the transmitter 1 and the matching device 3, a phase meter 4 for measuring the phase of the antenna 2 including the matching device 3 viewed from the transmitter 1, an impedance meter 5 for measuring impedance, and a VSWR are provided. V for measuring
Each SWR meter 6 is provided. The control circuit 7
The matching device drive circuit 8 is controlled so that the predetermined VSWR is achieved according to the values of the phase and the impedance. The matching device driving circuit 8 changes L and C according to the output signal of the control circuit 7,
Drive K1 or K2.

(Explanation of Operation) FIG. 3 is a flow chart of the automatic antenna matching system. At the start of automatic matching, first the matching device 3
The matching form of is investigated (S1). At the time of initial, the short matching operation is selected. That is, the matching operation is started from the states of L = 0 (short), C = 0 (open), K1 and K2 open (S2). Details of the short matching operation are shown in FIG. The values of L and C that are the minimum VSWR values are set by the matching operation (S3). Finally,
The values of L and C and the states of K1 and K2 are stored in the memory (not shown) in the control circuit 7 (S4), and the automatic matching is completed.

After the completion of this automatic alignment, the state of the antenna 2 changes, VSWR becomes a predetermined value or more, and when realignment is performed, the previously set alignment format is selected. S
5 shows the details of the direct L matching operation of FIG. 2, FIG. 6 shows the details of the CL matching operation, FIG. 7 shows the details of the parallel C matching operation, and FIG. 8 shows the details of the LC matching operation.

(Short Matching Operation) The short matching operation will be described with reference to FIG. First, the matching device 3 is set to the initial state. That is, L and C are set to zero and K1 and K2 are opened (P1). With the matching device 3 removed, the phase of the antenna 2 is measured to determine whether it is capacitive or inductive (P2). Four operations are performed depending on this phase value and the impedance measured at P8 described later, that is, in which quadrant of the Smith chart in FIG. 1B the antenna impedance is.

If it is in the quadrant, it is determined that the phase φ> 0 (P2). Therefore, K2 shorts (P3) and C
Is increased (P4). The increase of C is repeated until the input impedance on the matching device 3 side becomes capacitive (φ <0) (P5). Next, it is determined that the input impedance on the matching device 3 side is higher than the nominal impedance of the transmitter 1 (Z> Z0) (P8). K1 open, K2 shorted (no change in quadrant) (P9), L when Z> Z0
The C matching operation is performed (P10). The details of P10 are
It becomes FIG. In the automatic matching process, L, C, K
When 1 or K2 is changed, VSWR is measured, and when the VSWR is less than or equal to a predetermined value, the automatic matching ends.

If it is in the quadrant, it is determined that the phase φ <0 (P2). Increase L (P6). The increase of L is repeated until the input impedance on the matching device 3 side becomes inductive (φ> 0) (P7). Next, it is determined that the input impedance on the matching device 3 side is higher than the nominal impedance of the transmitter 1 (Z> Z0) (P8). K1 open, K2
Short-circuiting (P9), LC matching operation when Z> Z0 is performed (P10). The details of P10 are shown in FIG.
Also, in the automatic matching process, L, C, K1, or K
When 2 is changed, VSWR is measured, and when the value becomes less than or equal to a predetermined value, the automatic matching ends.

If it is in the quadrant, it is determined that the phase φ <0 (P2). Increase L (P6). The increase of L is repeated until the input impedance on the matching device 3 side becomes inductive (φ> 0) (P7). Next, it is determined that the input impedance on the matching device 3 side is lower than the nominal impedance of the transmitter 1 (Z <Z0) (P8). K1 short, K2
It is opened (P11) and the CL matching operation is performed when Z <Z0 (P12). The details of P12 are shown in FIG. Further, in the automatic matching process, when L, C, K1, or K2 is changed, VSWR is measured, and when the value is equal to or less than a predetermined value, the automatic matching ends.

If it is in the quadrant, it is determined that the phase φ> 0 (P2). Therefore, K2 shorts (P3) and C
Is increased (P4). The increase of C is repeated until the input impedance on the matching device 3 side becomes capacitive (φ <0) (P5). Next, it is determined that the input impedance on the matching device 3 side is lower than the nominal impedance of the transmitter 1 (Z <Z0) (P8). K1 short, K2 open (P1
1), CL matching operation is performed when Z <Z0 (P1
2). The details of P12 are shown in FIG. Further, in the automatic matching process, when L, C, K1, or K2 is changed, VSWR is measured, and when the value is equal to or less than a predetermined value, the automatic matching ends.

In the above description of each quadrant, the relationship with claim 2 will be shown. P1 is the first stage, P2 is the second stage, P
3 to P7 is the third stage, P8 is the fourth stage, P9 is the fifth stage, P10 is the sixth and tenth stages, and P11 is the seventh stage.
, P12 corresponds to the eighth and tenth stages, and measuring VSWR corresponds to the ninth stage.

(Z> Z0: LC matching operation) The subroutine of P10 in the case of the quadrant will be described with reference to FIG. This subroutine is the operation shown on the right side of FIGS. 1 (c) and 1 (d). C is increased by one step (P10-1), and the phase of the input impedance on the matching device 3 side is measured (P1).
0-2). In the case of inductive (φ> 0), L is decreased (P10-3) and repeated until capacitive (φ <0) (P10-4). Next, the input impedance on the matching device 3 side is lower than the nominal impedance of the transmitter 1 (Z <Z
The operation from P10-1 to P10-4 is repeated until it is determined to be 0) (P10-7), and the process exits from the subroutine.

If P10-2 is capacitive (φ <0),
L is increased (P10-5) and repeated until it becomes inductive (φ> 0) (P10-6). Next, until it is determined that the input impedance on the matching device 3 side is lower than the nominal impedance of the transmitter 1 (Z <Z0), P10-1, P10-
2, the operations of P10-5 and P10-6 are repeated (P10
-7), get out of the subroutine.

(Z <Z0: CL matching operation) The subroutine of P12 in the case of the quadrant will be described with reference to FIG. This subroutine is the operation shown on the right side of FIGS. 1 (e) and 1 (f). Increase L by one step (P12-1),
The phase of the input impedance on the matching device 3 side is measured (P
12-2). In the case of capacitive (φ <0), C is decreased (P12-3) and repeated until inductive (φ> 0) (P12-4). Next, the input impedance on the matching device 3 side is higher than the nominal impedance of the transmitter 1 (Z> Z).
The operation from P12-1 to P12-4 is repeated until it is determined to be 0) (P12-7), and the process exits from the subroutine.

In the case of P12-2 being inductive (φ> 0),
C is increased (P12-5), and the process is repeated until it becomes capacitive (φ <0) (P12-6). Next, until it is determined that the input impedance on the matching device 3 side is higher than the nominal impedance of the transmitter 1 (Z> Z0), P12-1, P12-.
2, the operations of P12-5 and P12-6 are repeated (P12
-7), get out of the subroutine.

(Direct L alignment operation) After the completion of this automatic alignment,
When the state of the antenna 2 changes, VSWR becomes equal to or greater than a predetermined value and re-matching is performed, the previously set matching format is selected. Details of the direct L matching operation of S2 of FIG. 3 are shown in FIG. In this case, L becomes zero, and when L cannot be reduced, the short matching operation of FIG. 4 is returned to. Other operations are
The operation is similar to that of FIG.

(CL alignment operation) After the completion of this automatic alignment,
When the state of the antenna 2 changes, VSWR becomes equal to or greater than a predetermined value and re-matching is performed, the previously set matching format is selected. Details of the CL matching operation in S2 of FIG. 3 are shown in FIG. In this case, when C becomes zero and C cannot be reduced,
Or when C becomes the maximum and C cannot be increased,
Return to short matching operation. Details of Z> Z0: CL matching operation are shown in FIG. Other operations are the same as those in FIG.

Next, the CL matching operation will be described with reference to FIG. At the time of initializing, the input impedance of the antenna 2 was at point A, but it was matched to point B by the matching device 3. When the input impedance of the antenna 2 changes to point C, the matching point becomes point D. Therefore, φ> 0 in FIG. 6, and C is increased. If VSWR still does not fall below the predetermined value, the CL matching operation of Z> Z0 is performed.
Further, when the input impedance of the antenna 2 changes to point E, the matching point becomes point F. Therefore, φ <0 in FIG.
And C is decreased. Even if the VSWR does not fall below the predetermined value, the CL matching operation of Z <Z0 is performed. These operations are matching operations from the points D and F to the point B shown by the dotted lines. That is, it is possible to shorten the processing time of the solid line from point C to point D and point E to point F.

(Normal C Alignment Operation) After completion of the automatic alignment,
When the state of the antenna 2 changes, VSWR becomes equal to or greater than a predetermined value and re-matching is performed, the previously set matching format is selected. Details of the normal C matching operation of S2 of FIG. 3 are shown in FIG. In this case, C becomes zero, and when C cannot be reduced, the short matching operation of FIG. 4 is resumed. Other operations are
The operation is similar to that of FIG.

(LC matching operation) After completion of the automatic matching,
When the state of the antenna 2 changes, VSWR becomes equal to or greater than a predetermined value and re-matching is performed, the previously set matching format is selected. Details of the LC matching operation in S2 of FIG. 3 are shown in FIG. In this case, if L becomes zero and L cannot be reduced,
Or if L becomes maximum and L cannot be increased,
Return to short matching operation. Z <Z0: Details of the LC matching operation are shown in FIG. Other operations are the same as those in FIG.

Next, the CL matching operation will be described with reference to FIG. At the time of initializing, the input impedance of the antenna 2 was at point A, but it was matched to point B by the matching device 3. When the input impedance of the antenna 2 changes to point C, the matching point becomes point D. Therefore, φ <0 in FIG. 8 is established, and L is increased. If VSWR still does not fall below the predetermined value, the LC matching operation of Z <Z0 is performed.
Further, when the input impedance of the antenna 2 changes to point E, the matching point becomes point F. Therefore, φ> 0 in FIG.
And L is decreased. If VSWR still does not fall below the predetermined value, the LC matching operation of Z> Z0 is performed. These operations are matching operations from the points D and F to the point B shown by the dotted lines. That is, it is possible to shorten the processing time of the solid line from point C to point D and point E to point F.

(Effect of the first embodiment) By adding an impedance meter as a detector, the matching algorithm is selected from the value of the antenna constant to shorten the matching time. Therefore, the better the VSWR before the start of matching, the shorter the matching time. In addition, after performing automatic matching once (VSWR
Is preset in good condition. ) The reconciliation time is short at the time of automatic realignment. This is because matching can be started from preset L and C values.

[Second Embodiment] (Structure) FIG. 15 is a block diagram showing another embodiment of a matching device used in an automatic antenna matching device. In the first embodiment, the values of L and C are changed by a step motor or the like. On the other hand, in the second embodiment, a plurality of elements are provided, and the element (element value changes in binary) is opened or shorted by a relay to select the element.

(Effect of the second embodiment) Although the number of L, C, and relays is larger than that of the first embodiment, the motor drive section can be eliminated. Therefore, when the transmission output is small,
It can be constructed inexpensively.

[0039]

As described above, according to the antenna automatic matching apparatus or the antenna automatic matching system of the present invention, the input impedance of the antenna 2 is on the Smith chart,
, Which includes a phase meter 4 and an impedance meter 5 for detecting which quadrant of
The matching operation of L and C in the matching box 3 is performed so that is equal to or less than a predetermined value. An appropriate matching operation is performed depending on the phase of the input impedance of the antenna 2 and the state of the actual resistance. for that reason,
Matching time can be shortened. Also, the better the VSWR before the start of matching, the shorter the matching time. That is, the re-automatic alignment time after performing the automatic alignment once becomes short.

[Brief description of drawings]

FIG. 1 is a Smith chart diagram for explaining an operation concept of the present invention.

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

FIG. 3 is a flowchart showing the operation of one embodiment of the present invention.

FIG. 4 is a flowchart illustrating a short matching operation.

FIG. 5 is a flowchart illustrating a direct L matching operation.

FIG. 6 is a flowchart illustrating a CL matching operation.

FIG. 7 is a flowchart illustrating a normal C matching operation.

FIG. 8 is a flowchart illustrating an LC matching operation.

FIG. 9 is a flowchart illustrating a subroutine of an LC matching operation of Z> Z0.

FIG. 10 is a flowchart illustrating a subroutine of a CL matching operation in which Z <Z0.

FIG. 11 is a flowchart illustrating a subroutine of CL matching operation of Z> Z0.

FIG. 12 is a flowchart illustrating a subroutine of an LC matching operation in which Z <Z0.

FIG. 13 is a Smith chart diagram for explaining the concept of CL matching operation when the antenna input impedance changes.

FIG. 14 is a Smith chart diagram for explaining the concept of the LC matching operation when the antenna input impedance changes.

FIG. 15 is a block diagram showing a second embodiment of the matching device of the present invention.

FIG. 16 is a Smith chart for explaining the operation concept of the conventional automatic matching method.

[Explanation of symbols]

1 ... Transmitter, 2 ... Antenna, 3 ... Matching device, 4 ... Phase measuring means, 5 ... Impedance measuring means, 6 ... Voltage standing wave ratio measuring means, 7 ... Control circuit, 8 ... Matching device drive circuit, C ... Variable branch capacitance, K1, K2 ... Variable branch capacitance coupling means, L ... Variable series inductance.

Claims (3)

[Claims] 1. A variable branch inductance (L) inserted between a transmitter (1) and an antenna (2) and a variable branch capacitance (C) for coupling the variable branch capacitance (C) to one of the antenna and the transmitter. Coupling means (K1, K2)
An automatic antenna matching device for matching a transmitter to an antenna, the phase measuring means (4) for measuring the phase of the input impedance of the matching device as seen from the transmitter side; Impedance measuring means (5) for measuring the input impedance of the matching device viewed from the machine side, voltage standing wave ratio measuring means (6) for measuring the voltage standing ratio of the transmitter and the antenna, and the phase and input impedance And a control circuit (7) for controlling the series inductance, the variable branch capacitance, and the variable branch capacitance coupling means to set the voltage standing ratio to a predetermined value in accordance with the above. 2. A variable branch capacitance (C) for coupling a variable series inductance (L) inserted between a transmitter (1) and an antenna (2) and a variable branch capacitance (C) to one of the antenna and the transmitter. In the antenna automatic matching method for matching the transmitter to the antenna by operating the matching device (3) having the coupling means (K1, K2), L, C, K1 and K2 are initialized and the matching device is The first step of pulling out, the second step of measuring the phase of the input impedance of the antenna in the first step, the operation of L or C, and K1 or K2 to insert the matching unit, the transmitter The third step of making the input impedance of the matching device as seen from the side a real resistance, the fourth step of measuring the real resistance, and K1 ohms when the real resistance is higher than the nominal impedance of the transmitter. Pun, K2 shorting the fifth step, after the fourth step, the sixth step of changing L and C in the direction of lowering the actual resistance, and if the actual resistance is lower than the nominal impedance of the transmitter, K7 short and K2 open, 7th step, 7th step, 8th step of changing L and C in the direction of increasing impedance, 9th step of measuring voltage standing ratio between transmitter and antenna And the tenth step of repeating the sixth step or the eighth step until the voltage standing ratio becomes equal to or lower than a predetermined value, the automatic antenna matching method. 3. A step of storing the states of L, C, K1 and K2 at the time of completion of the matching, and a step of re-matching from the status at the completion of matching when the voltage standing ratio of the transmitter and the antenna exceeds a predetermined value. Selecting a matching process corresponding to the stored states of L, C, K1, K2 to start the process; measuring the phase of the input impedance of the antenna in the rematching process; An automatic antenna matching method, characterized in that L or C set according to a value is varied to make the input impedance of the matching device a real resistance.