JPS63316526A - Method for matching antenna sharing device - Google Patents

Abstract

PURPOSE:To easily and correctly execute the matching of a transmitting receiving antenna at a wide frequency band by utilizing the channel setting signal of respective transmitters or receivers, storing the matching information corresponding at the rate of 1:1 with the setting signal into a memory circuit and controlling a matching circuit with the matching information. CONSTITUTION:The digital output signal of a transmitter TX is inputted to a memory circuit ROM, a transmitter and a channel used at the ROM are discriminated and a driving circuit is operated so that a variable inductance and a variable capacitor in the matching circuit composed of a variable filter connected to a transmitter output edge can be a prescribed value. At the driving circuit, an information signal outputted from the ROM is converted into an analog signal, inputted through a comparing circuit, inputted to a direct current amplifier and a servo motor to operate the variable inductance and the variable capacitor in a BPF is driven with the output of the direct current amplifier. To a comparing circuit, a position signal from a moving part is fed back and the moving part is controlled. Even concerning the receiver circuit, an antenna can be matched in the same way as a transmitter circuit.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an antenna duplexer used when a single antenna is used for multiple transmitters or receivers when there is little equipment space in buildings, ships, etc. Regarding the matching method.

(Prior art) When communicating using multiple transmitters with multiple channels, each transmitter is provided with a dedicated antenna, but ships and ships have limited equipment space, and multiple antennas are required. Since equipping a transmitter with a transmitter increases the cost, it has been common practice to share one antenna with multiple transmitters as shown in FIG.

The configuration and operation of the prior art will be briefly explained using the figure.

In the same figure, TRXI, TRX2. TRX3 is a transmitter, and a detector WD is connected to each output terminal, and the output terminal of the WD is connected to a variable filter BPF.
Connect the output end to the antenna ANT.

Further, the signal obtained from the detector WD is input to the control circuit C0NT, and the output of the C0NT is used to control the variable filter BPF.
control.

In the circuit configured as described above, when multiple signals of frequency fc are output from the transmitter TRXI, if the impedance of the transmitter and the impedance of the antenna are not matched, that is, the transmission frequency and the variable filter BPF
If the passband frequency band of l does not match, the impedance seen from the output end of the transmitter to the variable filter will not be a pure resistance, but will include a capacitance C or inductance L component, voltage and current. As a result of the fact that the phases of the two waves are different from each other, a part of the transmitter output signal is reflected at the mismatched portion, and a standing wave is generated by the incident wave and the reflected wave. Therefore, the standing wave ratio (V, S, W, R) is detected and the variable filter BPF is controlled so that the standing wave ratio approaches 1 or IK.

In addition, even if the standing wave ratio is detected by the above method, the detector cannot distinguish whether it is due to the capacitance of the antenna or the inductance, and the direction of phase shift is also unknown, making it difficult to control the variable filter. The conventionally commonly used method is to replace the detector WD with a phase detector PD in the block diagram shown in Fig.
A method is adopted in which the phase difference between pressure and current is detected by comparison, and the inductance and capacitor values of the variable filter are controlled in proportion to the phase difference.

However, even in the Niga method, it is difficult to obtain uniformly good detector characteristics over a wide band such as the HP band (2 to 30 MHz). Because the system was divided into small bands and a detector was provided for each minute band, the system had the disadvantage of being complicated, expensive, and large.

(Object of the Invention) The present invention was made in order to solve the above-mentioned conventional drawbacks, and it converts the transmitter used and the frequency channel used into a setting signal, and uses the setting signal to control the variable filter BPF. It is an object of the present invention to provide a matching method for a transmitting antenna duplexer that can simplify the control of an automatically tuned filter by setting the value to a preset value, and can accurately match impedance even in a wide frequency band.

(Summary of the Invention) In order to achieve this object, the present invention has the following configuration.

That is, when one antenna is shared by multiple transmitters having multiple channels, a matching circuit is provided between the transmitter and the antenna, and the channel setting signal of each transmitter/receiver is used to connect the detected signal and the matching circuit. A storage circuit that stores matching information corresponding to one of the matching circuits is provided, and the matching circuit is controlled based on the matching information.

(Example of the invention) The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In this figure, the same symbols as in FIG. 2 shown in the prior art have the same meanings. TRXI, TRX2, and TRXn are transmitters, and the output ends of the transmitters are connected to respective variable filters BPF, and the outputs of the variable filters pBPF are connected to the antenna.

On the other hand, frequency information corresponding to the set channel is inputted from the transmitter to the storage circuit ROM, and the variable filter BPF provided at the output end of the transmitter used is controlled by the output of the ROM.

FIG. 3 is a block diagram showing an embodiment of the invention in some detail.

For example, if the signal oscillation method of the transmitter TX is a digital synthesizer, the digital signal used to set the channel to be used in the transmitter 'Il'X is inputted to the memory circuit ROM, A signal that operates a drive circuit so that the variable inductance and variable capacitor in the variable filter BPF connected to the output terminal of the transmitter become preset values by determining the transmitter and channel to be used in the ROM. Output. The set value is used to operate the capacitor and inductance of the variable filter BPF by taking into account minute impedance mismatch between the transmitter and antenna used and changes in the impedance of the antenna that change depending on the frequency used. . The drive circuit includes a digital-to-analog converter, a comparison circuit, and a DC amplifier.The information signals outputted from the storage circuit are converted into analog signals and input to the DC amplifier via the comparison circuit. The output of the amplifier operates a movable part such as a serther motor that operates a variable inductance and a variable capacitor in a variable filter, and further controls the movable part by feeding back a position signal from the movable part to the comparison circuit. It is something to do.

FIG. 4 shows a modified embodiment to which the present invention is applied.

The difference between this figure and the above figure 1 is that the frequency information signal output from the transmitter is input into a coaxial cable together with a high frequency signal and propagated, and the frequency information signal is extracted through the cable and stored. The drive system and variable filter are controlled by inputting the data to the circuit ROM. In the same figure, L
PP is provided to prevent leakage of high frequency signals propagating on the coax and impedance mismatch.

The circuit configured as described above is effective in saving costs when used in a case where the distance between the operating section and the antenna of a ship, pill, etc. is large.

In the embodiments of the present invention, only the transmitting operation has been described, but the same applies to receiving as well.Furthermore, although the transmitter has been described using a digital synthesizer-type oscillation method, the present invention is not limited to this. In transmitters using other methods, a signal linked to a channel changeover switch is obtained and inputted to the signal converter by providing a signal converter such as an address decoder between the transmitter and the memory circuit. Converts the frequency information signal into a frequency code,
Memory circuit ROM K may be manually operated. It is also obvious that a part of the drive circuit may be replaced with a microprocessor (MP[J) for control.

(Effects of the Invention) Since the present invention is configured and operates as described above, matching of the transmitter or receiver antenna is easy and accurate even when used in a wide frequency band. Eliminating the need to provide a detection section at the output end of each transmitter or receiver is effective in reducing cost and weight.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional circuit, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. 4 is a modified embodiment of the present invention. FIG. 2 is a block diagram illustrating an example. TRXI, TRX2. TRX/I...Transmitter/receiver. BPFl, BrF3. BPFn--variable 74 routers. ROM・・・・・・Memory circuit, LPF・
...Low-pass f-wave device, ANT...
・Open...Antenna. WD......Detector, C0NT...
・・・・・・Control circuit, C0NV・Mountain...
··converter. Patent Applicant: Toyo Tsushinki Co., Ltd. No. Z Chart Procedures Amendment September 2, 1985 Percent Office Nagatomi September 4, 1989 Submission 1
Display of the case 1988 Patent Application No. 152206 2 Name of the invention Matching method of antenna duplexer 3 Person making the amendment Relationship to the case Applicant Postal code 25: 3-01 Telephone 0467-74-
1131 (Representative) 753-4 Otari, Kanyo-cho, Koza-gun, Kanagawa Prefecture Date of procedural amendment order August 25, 1988 (shipment date) 5 Number of inventions increased by amendment 6 Target of amendment Drawings

Claims (1)

[Claims] When one antenna is shared by multiple transmitters or receivers having multiple channels, a matching circuit is provided between the transmitter or receiver and the antenna, and a channel setting signal for each transmitter or receiver is provided. 1. A method for matching an antenna duplexer, characterized in that a storage circuit is provided that stores matching information in one-to-one correspondence with the setting signal, and each of the matching circuits is controlled based on the matching information.