JPH11154842A - Booster device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent interference waves from being generated from a booster device and respective coaxial cables connected to the booster device and to prevent the reception defect of a peripheral television receiver by preventing the oscillation of an amplifier circuit or the like which is provided inside the booster device, without changing the appearance and case body, etc., of the conventionally used booster device. SOLUTION: Ferrite cores 14, 21 and 28 are respectively mounted to an UHF input terminal 4, a VHF input terminal 7 and an output terminal 10. At respectively connecting coaxial cables 3, 6 and 9 to the UHF input terminal 4, the VHF input terminal 7 and the output terminal 10, the respective ferrite cores 14, 21 and 28 are automatically mounted to the outer side of the respective coaxial cables 3, 6 and 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster device for amplifying a received signal obtained by a receiving operation of a television antenna and supplying the amplified signal to a television receiver.

[Summary of the Invention] The present invention amplifies a reception signal obtained by a reception operation of a television antenna,
By attaching a ferrite core to the input terminal or output terminal of the booster device without changing the substrate or housing of the amplifier circuit of the booster device supplied to the television receiver, the coaxial cable connected to the booster device can be connected. The purpose of the present invention is to eliminate the influence of the flowing common mode current and prevent oscillation of the booster device.

[0003]

2. Description of the Related Art Among households nationwide, about 1,700
In many homes, when receiving a television broadcast signal, a received signal received by an antenna is amplified by a booster device and supplied to a television receiver provided in each home.

FIG. 16 is a schematic diagram showing an example of standard receiving equipment for general households using such a booster device.

[0005] A receiving facility 101 shown in FIG.
Roof horse 104 installed on the top of the second roof 103
A BS antenna 106 provided at a predetermined portion of the roof horse 104, for example, a pole standoff 105; a mast 107 supported substantially vertically by the pole standoff 105 of the roof horse 104; A UHF antenna 108 to be attached, a VHF antenna 109 provided slightly below the upper end of the mast 107, a mast branch line stopper 110 provided in the middle of the mast 107, and a part 111 of the mast branch line stopper 110 and the roof 103 Between the mast 1
07 to prevent falling, and UHF
A plurality of coaxial cables 113, 114, and 115 for taking in the respective received signals obtained by the receiving operation of the antenna 108, the VHF antenna 109, and the BS antenna 106, and provided in the middle of the mast 107, and each of the coaxial cables 113 to
5, a booster device 116 that amplifies each received signal and combines them into one signal, and a signal amplified by the booster device 116 and combined into one signal to the inside of the house 102. One coaxial cable 117 for guiding, a separator 118 disposed in the house 102 to separate a signal supplied via the coaxial cable 117 into respective received signals,
, And receives the received signals separated by the separator 118, and
A television receiver 119 for displaying the contents of F television broadcasting and BS television broadcasting.

The UHF antenna 108, the VHF antenna 109, and the BS antenna 106 use the UHF television broadcast signal, the VHF television broadcast signal, and the BS
While receiving the television broadcast signals, the booster device 116 uses the VHF antennas 109 and U
Each of the received signals output from the HF antenna 108 and the BS antenna 106 is amplified and combined into one signal, and then supplied to a separator 118 via a coaxial cable 117. After being separated, UHF
The contents of the television broadcast, VHF television broadcast, and BS television broadcast are displayed.

[0007] In this case, the booster device 116 is provided as shown in FIG.
7, a booster body 120 attached to the lower side of the mast 107, and a BS-IF input terminal provided on the lower surface of the booster body 120 and connected to one end of a coaxial cable 115 connected to the BS antenna 106. 121, a waterproof cap 122 for preventing rainwater or the like from entering the BS-IF input terminal 121, and one end of a coaxial cable 113 provided on the lower surface of the booster main body 120 and connected to the UHF antenna 108. UH
F input terminal 123, a waterproof cap 124 for preventing rainwater or the like from entering the UHF input terminal 123, and a VHF antenna 1 provided on the lower surface of the booster main body 120.
09, a VHF input terminal 125 to which one end of the coaxial cable 114 is connected, and the VHF input terminal 125
Waterproof cap 126 to prevent rainwater from entering inside
And an output terminal 126 provided on the lower surface of the booster main body 120 and connected to one end of a coaxial cable 117 connected to the separator 118, and a waterproof cap 127 for preventing rainwater or the like from entering the output terminal 126. Have.

Then, the BS-IF input terminal 121, UH
The VHF antenna 109, the UHF antenna 108, the BS antenna 1 via the coaxial cables 113 to 115 connected to the F input terminal 123 and the VHF input terminal 125, respectively.
06 while receiving and amplifying each of the received signals output from the receiving terminal 126 while amplifying the received signals.
Is supplied to the separator 118 via the coaxial cable 117 connected to the.

[0009]

By the way, the conventional booster device 11 used in the receiving equipment 101 as described above.
6 is said to have a service life of approximately 7 to 10 years, but due to failure of the booster device 116 main body, poor wiring work, aging of the booster device 116, etc.
Even before the end of the useful life, positive feedback is applied to the amplifier circuit provided in the booster main body 120, and the amplifier circuit oscillates, and the booster main body 120 itself or a coaxial cable connected to the booster main body 120 is used. Unnecessary electromagnetic waves are radiated from 117, and there is a problem that unstable interference is given to a relatively wide area around the place where the booster device 116 is installed.

[0010] Even if such a disturbance occurs and a complaint such as poor reception is received by the Japan Broadcasting Corporation, it is found out at which home a booster device 116 provided in the home produces the disturbance wave. Due to the difficulties, in 1993, about 2,500 complaints were received annually, and even if the receiving environment, such as the density of houses, was considered, the national average was about 1
It is estimated that 82,500 households have suffered damage, but there is a problem that it is difficult to deal with it.

For this reason, although there is a strong demand for the development of a technique for solving such a problem, the booster device 11
6 is turned off once, and then turned on again, it is difficult to reproduce an interference phenomenon, such as unnecessary electromagnetic waves from the booster device 116 being eliminated. 107
Once installed, it is difficult to shield this booster device 116 from the surroundings,
There is a problem that it is difficult to know which part of the booster device 116 has become defective and unnecessary electromagnetic waves are being emitted.

In view of the above circumstances, according to the present invention, an amplifier circuit and the like provided in a booster device can be prevented from oscillating, whereby the booster device and the booster device are connected. It is an object of the present invention to provide a booster device capable of preventing an interference wave from being output from each coaxial cable and preventing a surrounding television receiver from receiving a poor reception.

According to the second aspect of the present invention, it is possible to prevent the amplification circuit and the like provided in the booster device from oscillating without changing the shape of the conventionally used housing or the shape of the connector. This provides a booster device that can reduce the manufacturing cost of the booster device to the same level as that of the conventional booster device and that can prevent interference waves from existing booster devices by retrofitting. It is an object.

According to the third aspect of the present invention, the common mode current flowing through the outer conductor of the coaxial cable can be efficiently absorbed so that the amplifier circuit provided in the booster device does not oscillate. An object of the present invention is to provide a booster device capable of preventing an interference wave from being output from a booster device or each coaxial cable connected to the booster device and preventing a surrounding television receiver from receiving a poor reception. I have.

[0015]

In order to achieve the above object, according to the present invention, there is provided a booster device for amplifying a reception signal obtained by a receiving operation of a TV antenna and sending the amplified signal to a television receiver. In the above, a magnetic material is disposed at any one or more of the input / output terminals constituting the booster device, and removes the influence of a common mode current flowing on the outer conductor of the coaxial cable connected to the input / output terminal. It is characterized by.

According to a second aspect of the present invention, in the booster device according to the first aspect, the magnetic material is a cylindrical magnetic material inserted into a terminal hole of a housing constituting the booster device. It is characterized in that it is either a cylindrical magnetic body arranged in the attached waterproof cap, or a ring-shaped magnetic body attached to the terminal hole constituting the booster device.

Further, according to a third aspect, in the booster device according to any one of the first and second aspects, the magnetic material is made of a ferrite material.

According to the above configuration, a magnetic material is disposed at one or more of the input / output terminals provided in the booster device, and a magnetic material is disposed outside the coaxial cable connected to the input / output terminals. Eliminating the effects of the common mode current flowing on the conductor prevents the amplification circuit etc. provided in the booster device from oscillating, thereby preventing the interference wave from the booster device and each coaxial cable connected to this booster device. , So that the surrounding television receivers do not receive poorly.

According to a second aspect of the present invention, as the magnetic body,
A cylindrical magnetic body inserted into a terminal hole of a housing constituting the booster device, a cylindrical magnetic body disposed in a waterproof cap attached to the booster device, or a terminal hole constituting the booster device By using one of the ring-shaped magnetic materials attached to the part, the amplification circuit etc. provided in the booster device can be changed without changing the shape of the housing or connector used conventionally. Oscillation is prevented so that the manufacturing cost of the booster device is reduced to the same level as that of the conventional booster device, and interference waves are not generated from the existing booster device by retrofitting.

Further, according to the third aspect of the present invention, by using a magnetic body made of a ferrite material as the magnetic body, a common mode current flowing through the outer conductor of the coaxial cable can be efficiently absorbed, and the inside of the booster device can be improved. To prevent oscillation from occurring in the amplifying circuit and the like provided in the device, thereby preventing interference waves from being output from the booster device and the respective coaxial cables connected to the booster device, so that the surrounding television receiver does not receive poorly. To do.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <Basic Principle of the Invention> Prior to detailed description of a booster device according to the present invention, a basic principle of the booster device according to the present invention will be described.

When each coaxial cable is connected to the BS-IF input terminal, UHF input terminal, VHF input terminal, output terminal, etc. of the booster device, for example, as shown in FIG. 8, the coaxial cable is connected to the output terminal 130 of the booster device. Cable 1
31 is connected, the center conductor 132 of the coaxial cable 131 is correctly connected to the electrode of the output terminal 130, and the coaxial cable 13 is connected by the ohmic band of the booster device.
1 if the outer conductor 133 is fixed and properly connected to the ground of the amplifier circuit board, the output terminal 13 of the booster device is provided.
The signal output from 0 can be confined in the coaxial cable 131 so that unnecessary electromagnetic waves are not radiated from the outer conductor 133 to the outside.

However, such a coaxial cable 1
When connecting 31 to the booster device, the ohmic band of the booster device (or the ground of the amplifier circuit board) and
Since it is difficult to reduce the contact resistance between the outer conductor 133 of the coaxial cable 131 and the coaxial cable 131 to zero,
It is difficult to reliably connect the outer conductor 133 to the ground of the amplifier circuit board of the booster device. Furthermore, the ohmic band of the booster device and the outer conductor 13 of the coaxial cable 131
3, the connection between the outer conductor 133 of the coaxial cable 131 and the ground of the amplifying circuit board becomes incomplete due to aging, wind and rain, etc., as shown in FIG. An impedance ZL is formed between the outer conductor 133 and the ground of the amplifier circuit board, and an equivalent circuit 135 as shown in FIG. 10 is formed between the output terminal on the booster device side and the coaxial cable 131. You.

Thus, when the output impedance of the booster device is ZA and the impedance of the coaxial cable 131 is ZO, the output terminal 13 of the booster device is
When the output signal e is output from 0, each impedance Z
The output signal e is divided by O and ZL to generate voltages eO and eL.
Is generated, and the voltage eO becomes the center conductor 1 of the coaxial cable 131.
32 and the outer conductor 133, and a voltage eL is applied between the outer conductor 133 of the coaxial cable 131 and the ground of the amplifying circuit board.
A common mode current flows through one outer conductor 133.

The outer conductor 133 of the coaxial cable 131
When the connection between the antenna and the ground of the amplifier circuit board of the booster device becomes incomplete, the center conductor 132 and the outer conductor 133 of the coaxial cable 131 function as the antennas 136 and 137 equivalently as shown in FIG. .

Therefore, the voltage eL applied between the outer conductor 133 of the coaxial cable 131 and the ground of the amplifier circuit board causes the outer conductor 133 of the coaxial cable 131 to be turned off.
When a common mode current flows through the outer conductor 133, an electromagnetic wave is radiated from the outer conductor 133, and this is reflected by the BS-I of the booster device.
A coaxial cable connected to the F input terminal, a coaxial cable connected to the UHF input terminal, a coaxial cable connected to the VHF input terminal, etc., enter a positive feedback circuit to form an amplification circuit of the booster device. Oscillates.

Therefore, in order to solve such a problem, the receiving equipment system and the measuring system are completely insulated from the ground while each coaxial cable is connected to the booster device, and the output terminal 130 is connected to the output terminal 130. Connected coaxial cable 1
31 is measured, and the outer conductor 133 is measured.
It is necessary to measure the intensity of the electromagnetic wave radiated to the surroundings, and adjust the amplification factor of the amplifier circuit based on the measurement result.

However, it is difficult to completely insulate the receiving equipment system and the measuring system from the ground while each coaxial cable is connected to the booster device even if such measurement is performed. Therefore, the effect of electromagnetic waves radiated from the coaxial cable 131 connected to the output terminal 130 to the outside cannot be effectively removed.

Therefore, the present inventor has described the characteristics of the common mode current flowing through such a coaxial cable 131.
From various viewpoints, attention was paid to the fact that the common mode current flows in only one direction as shown in FIG.

Further, as shown in FIG. 13A, in a normal state, when a current I flows through the conductor 138, a magnetic field H synchronized with the frequency of the current I is generated around the conductor 138. Electromagnetic waves are emitted to the outside. As shown in FIG. 13B, when a ferrite core 139 is attached to the conductor 138, a magnetic field H generated around the conductor 138 is collected inside the ferrite core 139. The magnetic flux B is converted into heat energy, and attention is paid to a point that unnecessary electromagnetic waves are not radiated from the conductor 138 to the outside. As a method to remove the effect of only the common mode current,
When the ferrite core 139 was attached to the coaxial cable 131, the electromagnetic wave radiated from the outer conductor 133 was reduced and almost completely eliminated.

Thus, the output terminal 1 of the booster device
From the coaxial cable 131 connected to 30 to the coaxial cable connected to the BS-IF input terminal of the booster device, the coaxial cable connected to the UHF input terminal, and the coaxial cable connected to the VHF input terminal. The return signal was set to zero, and it was found that the amplifier circuit of the booster device did not oscillate.

At this time, the ferrite core 139 is
As shown in FIG. 14A, an impedance circuit 142 in which a coil 140 and a resistor 141 are connected in parallel or FIG.
As shown in (b), since the coil 143 and the resistor 144 can be represented by any one of the impedance circuits 145 connected in series, by attaching the ferrite core 139 to the coaxial cable 131, Impedance circuits 142 and 145 that can equivalently express the ferrite core 139 in the outer conductor 133
Can be considered to be inserted in series.

Further, even if the ferrite core 139 is attached to the coaxial cable 131, as shown in FIG. 15, for a normal signal flowing through the coaxial cable 131, the device to which the coaxial cable 131 is connected (for example, 146, etc.), the direction of the signal current flowing through the center conductor 132 and the direction of the signal current flowing through the outer conductor 133 are reversed, and the directions of the magnetic fluxes generated in the ferrite core 139 by these signal currents are opposite to each other. Since the magnetic fluxes can cancel each other out, the impedance circuit 1 equivalently expressing the ferrite core 139
By optimizing the impedances 42 and 145, only the common mode current flowing in one direction can be absorbed by the ferrite core 139 without reducing the normal signal flowing through the coaxial cable 131.

As can be understood from the above description, in the booster device according to the present invention, a coaxial cable connected to the BS-IF input terminal, a coaxial cable connected to the UHF input terminal, and a VHF input terminal of the booster device. By attaching a ferrite core 139 to at least the coaxial cable 131 connected to the output terminal 130 of the coaxial cable or the coaxial cable 131 connected to the output terminal 130, the outer conductor 1
Even when a common mode current flows through the external power supply 33, unnecessary electromagnetic waves are radiated from the outer conductor 133 and are prevented from being positively fed back to the input side of the booster device. The circuit is prevented from oscillating.

According to the present invention, the ferrite core 139 is mounted on the coaxial cable 131 without changing the housing of a conventional booster device.
9, which not only makes it possible to retrofit the booster device currently used in ordinary households with the ferrite core 139 to realize the booster device according to the present invention, By simply adding the ferrite core 139 mounting process to the manufacturing process of each manufacturer that manufactures the booster device, the booster device according to the present invention can be realized, thereby minimizing the increase in the manufacturing cost of the booster device. Hold down,
Dissemination can be facilitated.

<< Embodiment of the Invention >> FIG. 1 is a schematic structural view showing an embodiment of a booster device according to the present invention using the above-described basic principle.

The booster device 1 shown in FIG. 1 has a booster body 2 formed in a box shape,
A UHF input terminal 4 provided on the lower surface of the UHF antenna, to which one end of a coaxial cable 3 connected to a UHF antenna is connected, a waterproof cap 5 for preventing rainwater or the like from entering the UHF input terminal 4, and a booster body 2 Is provided on the lower surface of the
A VHF input terminal 7 to which one end of the coaxial cable 6 connected to the HF antenna is connected, a waterproof cap 8 for preventing rainwater or the like from entering the VHF input terminal 7, and a lower surface of the booster main body 2, An output terminal 10 to which one end of the coaxial cable 9 connected to the separator is connected, and a waterproof cap 11 for preventing rainwater or the like from entering the output terminal 10 are provided.

Then, the VH is connected via the coaxial cables 3 and 6 connected to the UHF input terminal and the VHF input terminal.
Each of the received signals output from the F antenna and the UHF antenna is taken in, and while each received signal is amplified, the signals are combined into one signal and output from the output terminal 10.
The signal is supplied to the separator via the coaxial cable 9 connected to the separator 0.

In this case, as shown in FIG. 2, the output terminal 10 is inserted into and fixed to the opening 13 formed in the casing 12 of the booster body 2.
4 and the outer conductor 15 of the coaxial cable 9 inserted through the ferrite core 14 is pressed from the outside to
16 to fix the ohmic band 16 to the ground of the amplifier circuit board 35 (see FIG. 1), and an electrode 19 to which the center conductor 18 of the coaxial cable 9 is connected. And a screw 20 for fixing the center conductor 18 to the electrode 19. When a signal is output from an amplifier circuit provided in the booster main body 2, the center conductor of the coaxial cable 9 connected to the electrode 19 is provided. This is fed to the separator via 18.

At this time, the outer conductor 15 of the coaxial cable 9 and
The contact between the ground of the amplifier circuit board 35 and the ohmic band 16 is deteriorated, and the contact resistance between these outer conductors 15 and the ground of the amplifier circuit board 35 is increased.
5, the ferrite core 14
Thus, the energy of the magnetic field due to the common mode current is converted into heat energy so that unnecessary electromagnetic waves are not radiated to the outside.

The UHF input terminal 4 is provided with an EMI ferrite core 21 inserted and fixed in an opening formed in a casing 12 constituting the booster main body 2, and a coaxial ferrite core 21 inserted in the ferrite core 21. An ohmic band 23 for fixing the coaxial cable 3 by pressing the outer conductor 22 of the cable 3 from the outside, a plurality of screws 24 for fixing the ohmic band 23 to the housing 12, and a center conductor 25 of the coaxial cable 3
And a central conductor 25 connected to the electrode 26.
When a received signal is output from the UHF antenna to which the coaxial cable 3 is connected, the received signal is taken in, guided to the electrode 26, and amplified by the booster body 2. Input to the circuit.

At this time, the outer conductor 22 of the coaxial cable 3
The contact between the earth of the amplifier circuit board and the ohmic band 23 is deteriorated, and the contact resistance between the outer conductor 22 and the amplifier circuit board is increased.
Even if a current flows through the outer conductor 22, the ferrite core converts the energy of the magnetic field due to the current into thermal energy so that unnecessary signals do not enter the housing 12.

The VHF input terminal 7 has an EMI ferrite core 28 inserted and fixed in an opening formed in the housing 12 constituting the booster main body 2, and a coaxial inserted in the ferrite core 28. An ohmic band 30 for fixing the coaxial cable 6 by pressing the outer conductor 29 of the cable 6 from the outside, a plurality of screws 31 for fixing the ohmic band 30 to the ground of the amplifier circuit board, and a central conductor 32 of the coaxial cable 6 are connected. And a screw 34 for fixing the center conductor 32 to the electrode 33. When a received signal is output from a VHF antenna to which the coaxial cable 6 is connected, the received signal is taken in, 33
To the amplifier circuit provided in the booster main body 2.

At this time, the outer conductor 29 of the coaxial cable 6
The contact between the ground of the amplifier circuit board and the ohmic band 30 is deteriorated, and the contact resistance between the outer conductor 29 and the ground of the amplifier circuit board is increased. Even if a current flows, the ferrite core 28 converts the energy of the magnetic field due to the current into heat energy so that unnecessary signals do not enter the amplifier circuit.

As described above, in this embodiment, the UHF
Ferrite cores 14, 21, and 28 are attached to the input terminal 4, the VHF input terminal 7, and the output terminal 10, respectively.
When the coaxial cables 3, 6, 9 are connected to the HF input terminal 4, the VHF input terminal 7, and the output terminal 10, respectively, the ferrite cores 14,
Since 21 and 28 are automatically attached,
It is possible to prevent the amplification circuit and the like provided in the booster device 1 from oscillating without changing the appearance and the housing of the conventionally used booster device. By preventing interference waves from being output from the coaxial cables 3, 6, and 9 connected to 1, the surrounding television receivers can be prevented from receiving errors.

<< Embodiment of the Invention >> Then, with no ferrite core attached to the UHF input terminal, VHF input terminal and output terminal, the booster device oscillates, and as shown in FIG. When there is a spectrum showing interference near the color subcarrier, as shown in FIG.
TDK Z with impedance of about 180Ω at Hz
Each of three ferrites No. 032-0930 is formed into ferrite cores 14, 21, and 28, and as shown in FIG.
Ferrite cores 14, 21, and 28 are attached to the HF input terminal 4, the VHF input terminal 7, and the output terminal 10, respectively, and the coaxial cables 3, 6, 9 are connected to the UHF input terminal 4, the VHF input terminal 7, and the output terminal 10, respectively. Was connected, as shown in FIG. 5, the interference wave could be eliminated.

As can be seen from this, the oscillation of the booster device 1 can be eliminated by using the ferrite cores 14, 21, and 28.

<< Other Embodiments >> In the above-described embodiment, the ferrite cores 14, 21 and 28 are inserted into the openings 13 and the like formed in the housing 12, and the coaxial cables 3, 6 are inserted. , 9 are attached to the booster device 1, each coaxial cable 3, 6, 9 has a ferrite core 1
4, 21, and 28 are respectively mounted. As shown in FIG.
3, a ferrite core 14 is attached to the bottom surface of the housing 12, or as shown in FIG.
The ferrite core 14 may be arranged in the waterproof cap 11 attached to the device.

The UHF input terminal 4 and the VHF input terminal 7 have the same configuration and have the same structure.
8 may be attached.

In this case, when the coaxial cables 3, 6, 9 are connected to the UHF input terminal 4, the VHF input terminal 7, and the output terminal 10, the coaxial cables 3, 6, 9,
Each of the ferrite cores 14, 21 and 28 is automatically mounted on the outside of the device to prevent the amplification circuit and the like provided in the booster device 1 from oscillating, whereby the booster device 1 and the booster device By preventing interference waves from being output from the coaxial cables 3, 6, and 9 connected to 1, the surrounding television receivers can be prevented from receiving errors.

In the above-described embodiment, U
HF input terminal 4, VHF input terminal 7, output terminal 10,
The ferrite cores 14, 21 and 28 are respectively mounted, but only the output terminal 10 has the ferrite core 1.
4 may be attached.

Also in this case, it is possible to prevent the interfering radio wave from being radiated from the booster device 1 so as not to adversely affect the surrounding television receivers.

In the above-described embodiment, the ferrite cores 14, 21, and 28 are used, but a cylindrical member, a ring-shaped member, or the like made of another magnetic material is used. May be.

In this case as well, only by matching the magnetic characteristics of the magnetic material with the input / output characteristics of the UHF input terminal 4, VHF input terminal 7, and output terminal 10, similar to the above-described embodiment, It is possible to prevent the amplification circuit and the like provided in the booster device 1 from oscillating without changing the appearance and the housing of the conventionally used booster device. By preventing interference waves from being output from the coaxial cables 3, 6, and 9 connected to 1, the surrounding television receivers can be prevented from receiving errors.

[0055]

As described above, according to the present invention, in the booster device of the first aspect, it is possible to prevent the amplification circuit and the like provided in the booster device from oscillating. By preventing interference waves from being output from each coaxial cable connected to the booster device, it is possible to prevent the surrounding television receivers from receiving errors.

In the booster device according to the second aspect, the amplification circuit and the like provided in the booster device are prevented from oscillating without changing the shape of the conventionally used housing or the shape of the connector. This makes it possible to reduce the manufacturing cost of the booster device to the same level as conventional ones,
Interference waves can be prevented from being output from the existing booster device.

Further, in the booster device according to the third aspect, the common mode current flowing through the outer conductor of the coaxial cable can be efficiently absorbed so that the amplification circuit provided in the booster device does not oscillate. Thereby, it is possible to prevent the interference wave from being output from the booster device and the respective coaxial cables connected to the booster device, and to prevent the surrounding television receivers from receiving errors.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a booster device according to the present invention.

FIG. 2 is a sectional view showing a detailed configuration example of an output terminal portion shown in FIG.

FIG. 3 is a diagram showing an example of a spectrum characteristic of a booster device without a ferrite core.

FIG. 4 is a diagram showing an example of characteristics of a ferrite core used in an embodiment of the booster device according to the present invention.

FIG. 5 is a diagram showing an example of a spectrum characteristic of a booster device according to the present invention.

FIG. 6 is a sectional view showing another embodiment of the booster device according to the present invention.

FIG. 7 is a sectional view showing another embodiment of the booster device according to the present invention.

FIG. 8 is a schematic diagram showing an example of a connection relationship between a commonly used coaxial cable and a booster device.

9 is an equivalent circuit diagram of the coaxial cable shown in FIG.

FIG. 10 is an equivalent circuit diagram showing a relationship between the coaxial cable shown in FIG. 8 and a booster device.

FIG. 11 is an equivalent circuit diagram showing a relationship between the coaxial cable shown in FIG. 8 and a booster device.

FIG. 12 is an equivalent circuit diagram illustrating a common mode current generated in the coaxial cable shown in FIG.

FIG. 13 is a schematic diagram illustrating a generally known example of a relationship among a current, a magnetic field, and a ferrite core.

FIG. 14 is an equivalent circuit diagram of the ferrite core shown in FIG.

FIG. 15 is a schematic diagram illustrating a basic principle of a booster device according to the present invention.

FIG. 16 is a schematic configuration diagram illustrating an example of a general receiving facility provided in a home.

17 is a schematic configuration diagram illustrating a configuration example of the booster device illustrated in FIG.

[Explanation of symbols]

 1: Booster device 2: Booster body 3, 6, 9: Coaxial cable 4: UHF input terminal 5, 8, 11: Waterproof cap 7: VHF input terminal 10: Output terminal 12: Housing 13: Opening hole (terminal hole) 14, 21, 28: Ferrite core (magnetic material) 15, 22, 29: Outer conductor 16, 23, 30: Ohm band 17, 20, 24, 27, 31, 34: Screw 18, 25, 32: Central conductor 19 , 26, 33: Electrode 35: Amplifier circuit board

Claims (3)

[Claims] 1. A booster device for amplifying a received signal obtained by a receiving operation of a TV antenna and sending the amplified signal to a television receiver, wherein one of the input / output terminals constituting the booster device is provided.
A booster device comprising: a magnetic body that is disposed at least one of them and that removes an influence of a common mode current flowing on an outer conductor of a coaxial cable connected to an input / output terminal. 2. The booster device according to claim 1, wherein the magnetic body is a cylindrical magnetic body that is inserted into a terminal hole of a housing that constitutes the booster device, and a waterproof cap attached to the booster device. A booster device, which is either a cylindrical magnetic material disposed in the inside or a ring-shaped magnetic material attached to a terminal hole portion constituting the booster device. 3. The booster device according to claim 1, wherein the magnetic body is made of a ferrite material.