JPH02261209A - Matching device in common use for antenna - Google Patents

Abstract

PURPOSE:To obtain an optimum selectivity by setting an optimum value of a variable capacitor of a primary circuit of a matching circuit. CONSTITUTION:A relay K4 is activated and a frequency from a transmitter 1 is detected, then a preset data set for each frequency is read from a memory 9 and a motor control circuit 8 presets capacitors C1-C4. A load detector 4 and a phase detector 5 adjust the capacitors C1, 2 to activate relays K1-3, and a transmission output is inputted to a secondary, circuit to adjust the capacitors C3, 4, thereby matching the secondary circuit and the transmitter 1. The processing above is repeated alternately and the primary and secondary circuits of the matching circuit 2 respectively converge the output impedance of the transmitter 1 and the impedance of a pseudo load R, thereby completing the matching to the load R. The antenna 6 is matched with the secondary circuit by adjusting the capacitors C3, 4 based on a signal from the detectors 4, 5 with the relays K1-4 inactivated, thereby matching the transmitter 1 and the primary circuit. Thus, optimum selectivity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antenna common matching device, and particularly to high precision matching thereof.

[Prior Art] FIG. 4 shows the principle of antenna common matching. In antenna common matching, multiple transmitters IA, IB.

IC and matching circuits 2A, 2B, 2C are connected to one antenna 6, and each transmitter IA, IB, IC has a different transmission frequency fl, f2 . With f3, the antenna 6 can be used in common. The matching circuits 2A, 2B, and 2C used for such antenna common matching must have the following functions in addition to the function of matching the transmitter output impedance to the antenna impedance with respect to its own transmitted waves. That is, regarding the transmitter IA, the matching circuit 2A performs matching operation for the transmission wave f1 to the antenna impedance including the load effect of the other shared matching circuit groups 2B and 2C, and the matching circuit 2A performs matching operation for the transmission wave f1 to the antenna impedance including the load effect of the other shared matching circuit groups 2B and 2C.
f3 has a selection characteristic that prevents it from entering the transmitter ]A. In order to perform antenna common matching, matching circuits 2A, 2B, and 2C are required that have selection characteristics that can sufficiently obtain separation between each transmitter IA and IBIC. IB, IC transmission frequencies fl, f2. The difference in f3 can be reduced.

FIG. 5 shows a schematic configuration of an antenna common matching device using a conventional double-tuned circuit. Shared matching circuit 2 is capacitor C1
, C2 and a coil L1, and a secondary circuit consisting of capacitors C3, C4 and a coil L2. Further, the shared matching circuit 2 has a narrowband bandpass filter configuration, and the antenna can be shared by a plurality of transmitters having different frequencies. A frequency counter 3 and a load detector 4 are connected between the shared matching circuit 2 and the transmitter 1.
and a phase detector 5 are connected.

Next, the procedure for matching to the antenna in the matching device shown in FIG. 5 will be described below.

(a) Set capacitor C4 to the minimum value. Close switch S1.

(b) Measure the transmission frequency with the frequency counter 3, and preset the capacitors C1, C2 and C3 based on the measured frequency.

(c) The capacitor C2 is controlled by the output of the phase detector 5 and tuned in parallel with the coil L1.

(d) Switch S1 is opened, and matching with antenna 6 is achieved by controlling capacitor C3 using the output of phase detector 5 and controlling capacitor C4 using the output of load detector 4.

In the above steps (b) and (c), the capacitors C1, C2 of the primary circuit are determined, but when considering the primary circuit, the load effect of the secondary circuit on the primary circuit must be considered. Also, this loading effect affects the transmitter 1 and the antenna 6.
It also has an important meaning in terms of consistency. That is, the matching between the transmitter 1 and the antenna 6 is performed in step 2 in the above procedure (d).
Controls capacitors C3 and C4 in the next circuit, transmitters 1 and 1
This is achieved by matching the secondary circuit, which takes advantage of variations in the loading effect of the secondary circuit on the primary circuit.

Therefore, by controlling the capacitors C3 and C4 of the secondary circuit, when the primary circuit and the transmitter 1 are matched, matching between the secondary circuit and the antenna 6 is achieved. The accuracy of matching to the antenna 6 depends on the accuracy of setting the capacitors C1 and C2.

In the conventional matching procedure, capacitor C is
4 as the minimum to increase the impedance seen from the antenna, and close switch S1 to avoid the influence of the secondary circuit on the primary circuit. , C2 are determined.

Therefore, after setting the capacitors c1 and 02, when tuning the capacitor C2 and the coil L2 and readjusting the capacitor C2, the influence of the coil L2 short-circuited by the switch s1 cannot be avoided.

Furthermore, in the conventional device, since there is no method for detecting the matching state of the secondary circuit, it has not been possible to confirm that the capacitors CI and C2 obtained in the primary circuit are appropriate values.

[Problems to be Solved by the Invention] Since the conventional antenna matching device has the above configuration, it is impossible to check whether the setting of the variable capacitor of the shared matching circuit is a reasonable value, and the antenna There was a problem in that a state of consistency could not be obtained and the selection characteristics were insufficient.

This invention was made to solve such problems, and it is possible to accurately determine the variable capacitor value of the shared matching circuit.
It is an object of the present invention to provide an antenna common matching device that achieves high-precision antenna matching and obtains sufficient selection characteristics.

[Means for Solving the Problems] An antenna common matching device according to the present invention includes a pseudo load device connected during adjustment of a common matching circuit, a load detector for detecting impedance seen from the transmitting side, a phase detector, and the above-mentioned. means for selectively switching and connecting a pseudo load to a primary side and a secondary side of a shared matching circuit; and a variable capacitor drive motor of the shared matching circuit based on signals from the load detector and the phase detector. and a microcomputer that outputs a control signal to a motor control circuit that controls the motor.

Further, the antenna common matching device according to the present invention provides control to a motor control circuit that controls the variable capacitor drive motor of the common matching circuit based on signals from a load detector and a phase detector that detect the impedance seen from the transmitting side. It has a microcomputer that outputs a signal, and an output detector that detects the output from the transmitter to the pseudo load and makes it possible to adjust the secondary side of the shared matching circuit.

[Operation] According to the present invention, the pseudo loader is connected to the secondary side of the shared matching circuit for precision matching, so that the load effect is minimized and the setting of the variable capacitor of the primary circuit can be accurately determined.

Therefore, the best selection properties are achievable.

In the first invention, the load detector, the +rJ detector, and the pseudo-negative CI device are alternately connected to the primary circuit and secondary circuit of the shared matching circuit, and the transmitted waves of the transmitter are alternately inputted. adjust each variable capacitor for precise matching.

According to the second invention, matching is simply performed using an output detector that detects the output obtained from the transmitter to the pseudo load via the secondary circuit of the shared matching circuit, and in this case, the circuit of the first invention The structure is simplified compared to the configuration, and the matching operation is also simple.

In either case, high-speed matching can be achieved by providing a function, for example, a memory, to preset the variable capacitor of the shared matching circuit near the matching state based on information from the frequency counter.

[Example] Next, the present invention will be described in more detail based on an example of the present invention shown in FIGS. 1, 2, and 3.

FIG. 1 shows a basic matching circuit of a shared matching circuit 2 according to the present invention. As shown in the figure, according to the present invention, a pseudo negative n:j resistor R is connected to the secondary circuit of the shared matching circuit 2, and the primary circuit of the shared matching circuit 2 is connected with the load effect minimized. The transmission wave from the transmitter 1 is input to accurately set the variable capacitors c1 and C2 of the primary circuit.

Examples embodying the idea of this invention are shown in Figures 2 and 3.
As shown in the figure. FIG. 2 shows an optimal embodiment of the first 1-Shimizu term, and FIG. 3 shows an optimal embodiment of claim (2).

In FIG. 2, the output of the transmitter 1 is input to the matching circuit 2 via a frequency counter 3 that detects the transmission frequency, a load detector 4 that detects the input impedance seen from the transmitter, and a tU detector 5. Ru.

Relay 4 switches the transmission output to antenna 6 or pseudo load R.

When determining the matching value of the variable capacitor C1°C2 in the primary circuit of the matching circuit 2, turn on relay 4 and use the pseudo load R. 2. to a relay Kl forming means for switching connection; 3 is interlocked with the primary circuit of matching circuit 2 or 2.
Selectively switch and input the transmission output to the next circuit.

In the matching operation, in preparation for matching to the antenna 6, matching is performed to the pseudo negative amplifier R, and the primary circuit capacitor CI,
After determining the optimum value of C2, matching with the antenna 6 is performed.

First, turn ON the relay 4, detect the transmission frequency from the transmitter 1 with the frequency counter 3, read the preset data for each frequency from the memory 9, operate the motor control circuit 8, and CI,
Set C2, C3, and C4 to preset values. Next, the capacitors C1 and C2 are adjusted based on the signals from the load detector 4 and the phase detector 5, and after the matching of the primary circuit is completed, the relay K1. , to 2. Turn on 3 and set the transmission output to 2.
Input into the next circuit and capacitors CB and C as in the primary circuit.
4 to match the secondary circuit and transmitter 1. By repeating this matching of the primary circuit and the secondary circuit alternately, the primary circuit and the secondary circuit of the matching circuit 2 are connected to the output impedance (50Ω) of the transmitter 1 and the pseudo load R, respectively.
The impedance converges to (50Ω) and the matching to the pseudo load R is completed. At this time, the capacitors ci, c of the primary circuit
2 obtains the optimal value.

Matching to the antenna 6 is performed by relay Kl, 2. 3°K4 is turned OFF, capacitors C3 and C4 are adjusted based on the signals from load detector 4 and phase detector 5, and transmitter 1
By matching the primary circuit with the antenna 6, the secondary circuit and the antenna 6 are matched.

The above operations are automatically controlled by the microcomputer 7, and automatic tracking is possible by maintaining the matching state of the primary circuit even when the antenna impedance changes.

In this way, when the matching operation is started, the capacitors C1, C2, C3, and C4 of the matching circuit 2 are preset based on preset data calculated in advance.
Preset data is stored for capacitors CI and C2. By setting the impedance of the pseudo load R to the output impedance (50Ω) of the transmitter 1, the matching circuit can be considered to be a symmetrical circuit, so the capacitors CI and C
2, C3, C4 presets are C1-C4, C2-C5
shall be. After presetting, matching of the primary circuit and matching of the secondary circuit are made into one step, and after matching the secondary circuit, this step is repeated until it is no longer necessary to match the primary circuit to converge to a matching state.

Capacitors C1 and C4 are variable load elements, capacitor C2
, C3 act as variable phase elements.

As a result of the above matching operation 4, the values of 01 and C2 for matching the primary circuit to the transmitter when the secondary circuit is in the matching state are determined and fixed to these values. When coupling to the antenna 6, the primary circuit and transmitter 1 can be matched by adjusting capacitors C3 and C4 in the secondary circuit to minimize the load effect on the primary circuit. Matching of the circuit and the antenna 6 is also achieved at the same time. Therefore, when the capacitors CI and C2 of the −degree primary circuit are determined, the best selection characteristics can be maintained by maintaining the matching of the primary circuit by adjusting capacitors C3 and C4 even when the antenna impedance changes. Automatic tracking is now possible.

In FIG. 3, the capacitor CI of the primary circuit.

The means for determining C2 is based on matching to the pseudo load R, as in the embodiment shown in FIG.

First, turn on relay 4 and preset capacitors C1, C2, C3, and C4 based on the transmission frequency.
The capacitors C1 and C2 are adjusted based on the signals from the load detector 4 and the phase detector 5, and the transmitter 1 and the primary circuit are matched.

Next, matching between the secondary circuit and the pseudo load R is performed by the output detector 10 that detects the transmission output from the transmitter 1 to the pseudo load R.
By maximizing the output from the capacitors C3 and C4, matching between the secondary circuit and the pseudo load R is achieved. By repeating this matching of the primary circuit and the secondary circuit alternately, a result similar to that of the embodiment shown in FIG. 2 can be obtained. The alignment with the antenna 6 is performed in the same manner as in the embodiment shown in FIG. 2, and the above operation is automatically controlled by the microcomputer 9.

As described above, according to the present invention, the pseudo loader is connected to the secondary side of the shared matching circuit to minimize the load effect, and the variable capacitors C1 and C2 of the primary circuit of the matching circuit 2 are matched, so that accurate settings can be made. A device with good selection characteristics can be obtained.

[Effects of the Invention] As explained above, this invention has a structure in which the optimum value of the variable capacitor in the primary circuit of the matching circuit can be set, so that precise impedance matching to the antenna is possible, and optimum selection characteristics are achieved. This has the effect of providing a device with

Further, by performing automatic matching using a microcomputer and presetting the variable capacitor, it is possible to achieve the effect of enabling high-speed matching operation.

[Brief explanation of drawings]

FIG. 1 is a basic circuit diagram of impedance matching according to the present invention, FIG. 2 is a block diagram showing an embodiment of the first claim of the present invention, and FIG. 3 is a basic circuit diagram of an impedance matching according to the present invention. FIG. 4 is an explanatory diagram showing the concept of antenna common matching, and FIG. 5 is a block diagram of a conventional antenna common matching device. 1 ... Transmitter 2 ... Antenna common matching circuit 3 ... Frequency counter 4 ... Load detector 5 ... Phase detector 6 ... Antenna 7 ... Microcomputer 8 ... Motor Control circuit 9... Memory 10... Output detector CI, C2, C3, C4... Variable-i capacitor L1
．． L2... Coil R... Pseudo load device

Claims (2)

[Claims] (1) A matching circuit that is connected between an antenna and a plurality of transmitters to share a single antenna, and a frequency detector that detects the frequency of a transmission wave input from the transmitter to the shared matching circuit;
A load detector detects the impedance value seen from the transmitting side to the load side, a phase detector detects the phase of the impedance seen from the transmitting side to the load side, and the operation of the shared matching circuit according to the signals from these detectors. a microcomputer that detects the state and matching state and outputs a signal for controlling the shared matching circuit; a pseudo load device that is connected when adjusting the shared matching circuit; the frequency detector, the load detector, the phase detector and the pseudo load device; means for selectively switching and connecting the load device to the primary side or the secondary side of the shared matching circuit; and a motor for controlling a drive motor that drives and adjusts the variable capacitor of the shared matching circuit in accordance with the signal output from the microcomputer. An antenna common matching device comprising a control circuit. (2) A common matching circuit connected between the antenna and multiple transmitters, a frequency detector that detects the frequency of the transmitted wave input from the transmitter to the common matching circuit, and an impedance seen from the transmitting side to the load side. A load detector detects the impedance value, a phase detector detects the phase of the impedance seen from the transmitting side to the load side, and the operating state and matching state of the shared matching circuit are detected according to the signals from these detectors. a microcomputer that outputs a signal for controlling the shared matching circuit; a pseudo load connected when adjusting the shared matching circuit; an output detector that detects an output from a transmitter to the pseudo load; An antenna shared matching device comprising a motor control circuit that controls a drive motor that drives and adjusts a variable capacitor of the shared matching circuit in accordance with an output signal.