JP2007166236A - Booster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a booster that can prevent a modulation signal from being emitted from an antenna with a simple configuration and the installation work of which is facilitated although the booster mixes a broadcast signal received by the antenna and the modulation signal and outputs the mixed signal. <P>SOLUTION: The booster 2 includes an amplifier 4, which receives the television broadcast signal received by the antenna 6 and amplifies the signal. A mixer 8 is provided to an output side of the amplifier 4. The mixer 8 composes the modulation signal with an output signal from the amplifier 4 to provide an output. The modulation signal results from modulating a high frequency carrier signal with a baseband signal from a video camera 18, a VTR or a DVD player 20 at a modulation signal generator 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a booster that amplifies a broadcast signal such as a television broadcast signal received by an antenna.

  An image captured by a video camera may be viewed on a television receiver using a transmission line that transmits a television broadcast signal received by an antenna. An example of this technique is disclosed in Patent Document 1. According to the technique of Patent Document 1, a mixer is provided in the middle of a cable for transmitting a television broadcast signal received by an antenna, and a modulator modulates a modulation signal of a specific channel in the UHF band with a video signal from an interphone camera In the mixer, the modulation signal and the television broadcast signal are mixed and transmitted to the monitor.

JP 07-59076 A

  In the technique of Patent Document 1, when the modulated signal is mixed with a television broadcast signal, it is necessary to prevent the modulated signal from being radiated from the antenna. Therefore, the mixer is often provided after the isolation amplifier to which the television broadcast signal is supplied. This is to utilize the fact that the modulation signal is not easily transmitted from the output side of the isolation amplifier to the antenna side due to the installation of the isolation amplifier. However, in this case, since the isolation amplifier and the mixer must be prepared separately and installed, the assembly is troublesome. Moreover, if an isolation amplifier is provided, sufficient isolation cannot be obtained, and a modulated signal may be radiated from the antenna. In such a case, a television broadcast is provided between the antenna and the isolation amplifier. In order to amplify the signal and not transmit the modulated signal to the antenna side, a separate booster must be provided, which further increases the complexity of the configuration and makes assembly difficult.

  An object of the present invention is to provide a booster that prevents a modulation signal from being radiated from an antenna with a simple configuration.

  The booster of one embodiment of the present invention includes amplification means. This amplification means inputs and amplifies a broadcast signal received by an antenna, for example, a high frequency signal such as a television broadcast signal or FM radio broadcast. Mixing means is provided on the output side of the amplification means. This mixing means synthesizes and outputs the modulation signal and the output signal of the amplification means. The output destination may be, for example, a home receiving means such as a television receiver or an FM radio receiver, or may be input to the head end of the joint reception system and supplied to each terminal of the joint reception system. it can. The modulation signal is obtained by modulating a high-frequency carrier signal with a baseband signal from, for example, a video camera, a VTR, or a DVD player.

  The booster thus configured is interposed in the transmission line from the antenna. When the modulated signal is mixed with the broadcast signal and transmitted, the modulated signal is supplied to the booster mixer. Since this booster includes a mixer, it is not necessary to provide a mixer on the output side of a normal booster. In addition, since mixing is performed on the output side of the booster, the modulation signal is not transmitted to the antenna side, and the modulation signal is not radiated from the antenna. Therefore, it is not necessary to reduce the level of the modulation signal in order to prevent radiation from the antenna, and reception can be satisfactorily performed by a receiver or the like. In addition, since the isolation can be accurately checked at the time of manufacturing the booster with a single booster, the level setting of the modulation signal becomes easy.

  Furthermore, it is desirable that the amplification means and the mixing means are accommodated in one housing. Further, another amplifying means can be provided on the output side of the mixing means. It is desirable to accommodate this another amplifying means in one housing. With this configuration, the modulation signal can be amplified by another amplifying means, so that the output level of the modulator can be reduced and the occurrence of intermodulation can be prevented. Similarly, since the isolation can be checked personally at the time of manufacture, the level setting of the modulation signal becomes easy.

  As described above, the booster according to the present invention can amplify the broadcast signal received by the antenna and can prevent the modulation signal from being radiated from the antenna, and can easily perform the necessary work. It is.

  As shown in FIG. 1, the booster 2 according to one embodiment of the present invention has amplification means, for example, an amplifier 4. The amplifier 4 is supplied with a broadcast signal received by the antenna 6, for example, a UHF band or VHF band television broadcast signal. The amplifier 4 amplifies the television broadcast signal. Mixing means, for example, a mixer 8 is provided on the output side of the amplifier 4. The mixer 8 mixes the output signal of the amplifier 4 supplied to its input terminal 10 and the modulation signal supplied to the mixing input terminal 12 and outputs it from its output terminal 14. As the mixer 8, for example, a normal one-branch can be used as it is. In this case, the output side of one branching device is used as the input terminal 10, the branch side is used as the mixed input terminal 12, and the input side is used as the output terminal 14. The output from the output terminal 14 becomes the output of the booster 2 and is supplied to a receiving means such as a television receiver (not shown) via a transmission line such as a coaxial cable (not shown). The amplifier 4 and the mixer 8 are accommodated in a single casing 16 and are disposed, for example, in the vicinity of the antenna 6.

  The modulation signal to the mixer 8 is generated by the modulation signal generator 17. The modulation signal generator 17 includes baseband signal generation means, for example, a surveillance video camera 18 and a VTR or DVD player 20, and baseband signals generated by these respectively are supplied to the television modulators 22 and 24. . The TV modulators 22 and 24 generate carrier signals of different channels, and these carrier signals are modulated by the baseband signal from the corresponding video camera 18 or the baseband signal from the VTR or DVD player 20, respectively. A modulation signal is generated. These modulation signals are combined by the combiner 26 and supplied to the mixing input terminal 12 of the mixer 8.

  In this booster 2, the modulation signal and the television broadcast signal can be mixed and supplied to the television receiver only by a simple operation of inputting the modulation signal to the mixing input terminal 12 of the booster 2. In addition, since the mixer 8 of the booster 2 is provided on the output side of the amplifier 4, sufficient isolation can be obtained by the amplifier 4, so that the modulation signal can be prevented from being radiated from the antenna 6. Therefore, the level of the modulation signal can be increased to a predetermined input level of the mixer 8, and a video obtained by demodulating the modulation signal can be satisfactorily viewed on the television receiver. In addition, since the amplifier 4 and the mixer 8 are combined from the beginning, the installation work is easy, and there is no variation in the characteristics of the two, and good isolation can be obtained.

  The mixed input terminal 12 is provided on the outer surface of the housing 16 so that the modulated signal from the modulated signal generator 17 is supplied to the mixed input terminal 12, but the booster 2 has a monitor circuit for monitoring the output. Since an output monitor terminal for taking out the monitor output to the outside may be provided on the outer surface of the housing 16, the output monitor terminal is connected to a selected one of the monitor circuit and the mixed input terminal. It is also possible to provide a selection switch to be used, and to use the output monitor terminal in common with the mixed input terminal. In this case, there is no need to secure a space for installing the mixed input terminal 12 in the housing 17.

  In the above embodiment, the output of the mixer 8 is transmitted as it is. However, the output of the mixer 8 can be transmitted after being amplified by another amplifier (not shown). In this case, it is desirable to accommodate another amplifier in the casing 16 together with the mixer 8 and the amplifier 4. By providing another amplifier in this way, the modulation signal can also be amplified, so there is no need to increase the level of the modulation signal supplied to the mixer 8 and it is possible to prevent intermodulation distortion from occurring during mixing. can do.

  In the above embodiment, the output of the booster 2 is supplied to the television receiver. However, the present invention is not limited to this. It is also possible to supply a mixed signal of a John broadcast signal and a modulation signal. In the above embodiment, the baseband signals from the surveillance video camera 18 and the VTR or the DVD player 20 are used, but only one of them can be used. In addition, baseband signals other than these, for example, baseband audio signals from a music playback device can be used. In the above-described embodiment, the television broadcast signal is received by the antenna 6, but the present invention is not limited to this. For example, an FM radio broadcast signal can be received.

It is a block diagram which shows the use condition of the booster of one Embodiment of this invention.

Explanation of symbols

2 Booster 4 Amplifier (Amplification means)
6 Antenna 8 Mixer 17 Modulation signal generator

Claims (3)

Amplifying means for inputting and amplifying a broadcast signal received by an antenna;
A mixing means provided on the output side of the amplifying means, which synthesizes and outputs a modulated signal obtained by modulating a high-frequency carrier signal with a baseband signal, and the output signal of the amplifying means;
It has a booster.   2. The booster according to claim 1, wherein the amplifying means and the mixing means are accommodated in one casing. 3. The booster according to claim 1, further comprising another amplifying means for amplifying the output signal of the mixing means.

Images