JP2003101421A - Signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compatible a problem in the compatibility of a new device and versatility available to a device up to the moment in a configuration where a received signal containing at least two signals received on one communication path is sent to a tuner unit by using a distribution unit. SOLUTION: The distribution unit and at least one tuner unit are covered with one metal casing as a front end module 2, and a distribution output terminal is provided for connecting a tuner unit 3 for video receiving, which is the other tuner unit, and the distributing unit. Concerning the distribution unit and the tuner unit in the same casing, compatibility can be exactly/accurately controlled in production. Further, by means of the distribution output terminal, a tuner unit under use up to the moment can be used in future as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing device used for a digital STB (Set Top Box) or the like capable of simultaneously receiving a plurality of modulated signals.

[0002]

2. Description of the Related Art An example of a block diagram around a front end supplied as a conventional STB (set top box) for a digital CATV (cable television) is shown in FIG.
9, shown in FIG. The operation around the front end of the CATV STB shown in FIG. 19 will be described below based on a typical STB for the United States.

Downstream signals (55.25 to 865.25 MHz) input from the input terminal (I) are
The tuner unit for video reception performs selection, amplification, frequency conversion, and band limitation, and outputs as a signal of 45.75 MHz. After that, the signal is demodulated by the corresponding demodulation circuit 131 according to the modulation method of the signal.

Next, the operation inside the tuner unit for video reception will be described. First, the input signal is amplified in the amplifier 121, and in the mixer 122, the oscillator 1
It is mixed with the oscillating signal generated at 23 and frequency converted. At this time, the frequency of the oscillation signal is changed according to the reception frequency. Next, the band pass filter 124 receives the necessary band limitation, the amplifier 125 amplifies the band, and the band pass filter 126 again limits the band. Next, in the mixer 127, the oscillator 12
The frequency is converted by mixing with the oscillation signal generated at 8. The output is amplified by the amplifier 129, band-limited by the band pass filter 130, and output.

The output terminal (II) is connected to a telephone line, and the upstream signal is subjected to necessary modulation by the modulator 134 and output.

The differences between the examples shown in FIGS. 19 and 20 are that the upstream signal is output using a telephone line (FIG. 19) and the cable line (FIG. 20).
The only difference is. Therefore, the explanation about FIG.
Only the points different from the description of FIG. 19 will be described.

In FIG. 20, the downstream signal input from the input terminal (I) is band-limited by the high-pass filter 141 and then amplified by the amplifier 121. In FIG. 20, the upstream signal (5-27M
Since (Hz) is output from the input terminal (I), the high pass filter 141 has a role of preventing the signal from interfering with the operation on the downstream side.

The upstream signal is also transmitted to the modulator 1.
After the necessary modulation is performed at 32, the signal is amplified by the amplifier 133, subjected to band limitation by the low-pass filter 151, and then output from the input terminal (I). The low-pass filter 151 has a role of preventing the downstream signal from interfering with the operation on the upstream side, and a role of preventing harmonics of the upstream signal from interfering with the upstream side.

It should be noted that the video receiving tuner unit shown in the figure is usually prepared as a front end unit. On the other hand, FIG. 21 shows an example of a block diagram around the cable modem front end, which has been widely used in recent years to connect to the Internet using the CATV network. Figure 21
The operation around the cable modem front end shown in FIG. 2 will be described below based on a typical cable modem for the United States.

The downstream signal (91 to 857 MHz) input from the input terminal (I) is subjected to selection, amplification, frequency conversion and band limitation in the data receiving tuner unit, and is output as a 43.75 MHz signal. It Then, it is demodulated by the QAM demodulation circuit 120.

Further, the upstream signal (5-42M
After the required modulation is performed by the modulator 132,
The signal is output from the input terminal (I) after being band-limited by the low-pass filter 151 inside the tuner unit for data reception and amplification by the amplifier 133.

Next, the operation inside the data receiving tuner unit will be described. The input signal is the high-pass filter 14
After being band-limited by 1, the signal is amplified by the amplifier 111. Next, the band pass filter 112 receives the necessary band limitation, and the amplifier 113 amplifies it.
Again, the band pass filter 114 limits the band. Next, in the mixer 115, it is mixed with the oscillation signal generated by the oscillator 116 and frequency converted.
The output is amplified by the amplifier 117, and the SAW filter 11
The band is limited in 8 and amplified and output again in the amplifier 119. The high-pass filter 14
The roles of 1 and the low-pass filter 151 are the same as in FIG.

Incidentally, a data receiving tuner unit shown in the figure is usually prepared as a front end unit. Conventionally, the STB for digital CATV and the cable modem were separately supplied. Therefore, when the CATV subscriber receives both services at the same time, the cable signal is distributed at each subscriber's house and then two sets are set. Had to connect to.

When two conventional sets are directly inserted into one set, it is necessary to prepare a signal distributor at the input section of the set. A block diagram of this set is shown in FIG. Here, normally, the distribution unit, the image receiving tuner unit, and the data receiving tuner unit shown in the figure are prepared as the front-end units, and have a three-unit configuration.

The operation of FIG. 22 will be described. The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 141, then distributed by the distributor 142 and distributed and output to the data receiving and video receiving tuner units. . The distributed and output signal is demodulated as in the description of FIGS. Also, there are two types of upstream signals, as shown in FIG.
Similar to the description in 9, the output from the output terminal (II) and the output from the input terminal (I) are band-limited by the low-pass filter 151 in the distribution unit as in the description in FIG. There are things that will be done.

The distribution unit may be electromagnetically coupled or
By electrostatic coupling, it is prepared as a unit surrounded by a metal medium to prevent unnecessary interference waves from coupling to the distributor, passing through the distributor, and leaking to the outside. It is a factor of cost increase.

Further, when the high frequency units are coupled, impedance matching is required and there is a problem such as coupling of interfering waves. Therefore, it is necessary to perform the performance evaluation in combination with each other in addition to the evaluation of a single product. is there.

[0018]

In a configuration in which all units are separately stored in individual housings, impedance matching between high frequency units can be adapted and interference between oscillators in each unit can be prevented. like,
It is necessary to newly adjust the compatibility between all units. In addition, since a housing is required for each, a large amount of housing material is required to cover the entire surface area, which increases the manufacturing cost.

Further, in the structure in which all the units are stored in one housing, the communication line (communication path) which has been used so far is used.
When attempting to perform new communication while diverting and distributing, the entire communication device must be replaced each time. Further, since the units are not separated from each other, heat generated in each unit has a great adverse effect on other units. If each tuner unit is equipped with an oscillator for frequency conversion of the received signal,
Interference between the oscillators may occur between the tuner units.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a signal processing device which can achieve both the compatibility problem of a new device and the versatility that can be used in the conventional devices. To provide.

[0021]

In order to solve the above problems, the signal processing apparatus of the present invention separates a received signal containing two or more signals received in one communication path into respective signals,
In a signal processing device including a distribution unit that sends each separated signal to a tuner unit corresponding to each signal, at least one of the tuner units and the distribution unit are covered with one metal housing, and It is characterized in that it is provided with a distribution output terminal for connecting the tuner unit and the distribution unit.

With the above structure, the distribution unit and at least one tuner unit are covered with one metal housing, and the distribution output terminal for connecting the other tuner unit and the distribution unit is provided.

According to the above arrangement, the distribution unit and the tuner unit housed in the same housing as the distribution unit can be accurately and precisely adjusted at the time of manufacture. In addition, since a single housing is sufficient for a plurality of units, it is possible to reduce the amount of housing material required and suppress an increase in manufacturing cost.

In addition, according to the above configuration, the tuner unit used so far can be used in the future at the distribution output terminal. Further, since the units are separated from each other, it is possible to reduce the adverse effect of heat generated in each unit on other units. Further, even when each tuner unit is provided with an oscillator for frequency-converting a received signal, it is possible to suppress interference between the oscillators between the tuner units.

Therefore, the compatibility problem of the new device and the versatility which can be used in the conventional device can be satisfied at the same time.

In addition to the above-mentioned structure, the signal processing apparatus of the present invention has a tuner unit covered with the above-mentioned distribution unit and one metal housing, wherein the distribution unit is a signal other than a cable television image signal. And the distribution output terminal outputs a cable television video signal.

With the above structure, the tuner unit covered with the distribution unit and one metal housing is
The distribution unit outputs a signal other than the cable television image signal, and the distribution output terminal outputs the cable television image signal.

Therefore, in addition to the effect of the above configuration, in an environment in which the cable television receiving device is already installed, the cable television receiving device is used while the cable television broadcast receiving and the other communication are used. be able to.

In addition to the above configuration, the signal processing apparatus of the present invention has a plurality of transmission signal input sections to which two or more transmission signals are respectively input, and the above-mentioned transmission signal input section. It is characterized in that a transmission path for transmitting at least one of the two or more transmission signals to the communication path is provided.

With the above configuration, at least one of a plurality of transmission signal input sections to which two or more transmission signals are respectively input, and at least one of the two or more transmission signals input to the transmission signal input section Is provided to the communication path.

Therefore, at least one of the two or more transmission signals is transmitted to the communication path. Therefore, in addition to the effects of the above configuration, it is possible to transmit at least one of the two or more transmission signals by utilizing the existing communication path.

Further, the signal processing device of the present invention is characterized in that, in addition to the above-mentioned configuration, it is provided with a coupling unit for coupling two or more of the above-mentioned transmission signals as a signal to be transmitted to the above-mentioned communication path.

With the above configuration, two or more transmission signals are combined and transmitted to the communication path. Therefore, in addition to the effects of the above configuration, it is possible to simultaneously transmit both two or more transmission signals by utilizing the existing communication path.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a low pass filter is provided for each transmission path between each of the transmission signal input sections and the coupling section. .

With the above structure, a low-pass filter is provided for each transmission path between each of the transmission signal input sections and the coupling section. Therefore, in addition to the effects of the above configuration, even if the bands of a plurality of transmission paths are different from each other, it is possible to provide an optimum low-pass filter for each.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a switching unit for switching the transmission signal to be transmitted to the communication path is provided.

With the above configuration, a switching unit for switching the transmission signal to be transmitted to the communication path is provided,
By switching two or more transmission signals, one of them is transmitted to the communication path. Therefore, in addition to the effect of the above configuration, it is possible to transmit while switching two or more transmission signals by utilizing an existing communication path.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a low pass filter is provided for each transmission path between each of the transmission signal input sections and the coupling section. .

With the above structure, a low-pass filter is provided for each transmission path between each of the transmission signal input sections and the coupling section. Therefore, in addition to the effects of the above configuration, even if the bands of a plurality of transmission paths are different from each other, it is possible to provide an optimum low-pass filter for each.

Further, the signal processing apparatus of the present invention is characterized in that, in addition to the above configuration, the distribution output terminal is provided with a coaxial cable with a connector.

With the above configuration, the distribution output terminals are
A coaxial cable with a connector is provided. Therefore, in addition to the effects of the above configuration, the compatibility between the respective members in the signal processing device, including the coaxial cable with the connector, can be adjusted accurately and precisely at the time of manufacturing.

In addition to the above configuration, the signal processing apparatus of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input, and a received signal input from the input section are provided in each tuner unit. And a distribution element for distributing to the input device, and an amplifier is provided between the input section and the distribution element.

With the above structure, an amplifier is provided between the input section and the distribution element. Therefore, in addition to the effect of the above configuration, it is possible to compensate for the loss of the signal level due to the distribution element.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a variable attenuation circuit is provided between the amplifier and the distribution element.

With the above structure, the variable attenuation circuit is provided between the amplifier and the distribution element. Therefore, in addition to the effect of the above configuration, when limiting the signal input level to each tuner unit to a certain level or less, it is possible to eliminate the need to provide each tuner unit with a variable attenuation circuit.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a variable attenuation circuit is provided between the input section and the amplifier.

With the above configuration, the variable attenuation circuit is provided between the input section and the amplifier. Therefore, in addition to the effect of the above configuration, when limiting the signal input level to each tuner unit to a certain level or less, it is possible to eliminate the need to provide each tuner unit with a variable attenuation circuit. Further, when the input signal level is high, the distortion generated in the amplifier can be reduced.

In addition to the above configuration, the signal processing apparatus of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input, and a received signal input from the input section are provided in each tuner unit. And a amplifier between the distribution element and the distribution output terminal.

With the above structure, the amplifier is provided between the distribution element and the distribution output terminal. Therefore, in addition to the effect of the above configuration, the signal input level to the tuner unit on the distribution output terminal side can be set to the optimum level.

In addition to the above structure, the signal processing device of the present invention further comprises:
It is characterized in that a variable attenuation circuit is provided.

With the above structure, the variable attenuation circuit is provided between the amplifier and the distribution output terminal. Therefore, in addition to the effect of the above configuration, by appropriately controlling the variable attenuation circuit according to the input signal level, the signal input level to the tuner unit on the distribution output terminal side is limited to the optimum fixed level or less. be able to.

Further, the signal processing device of the present invention is characterized in that, in addition to the above configuration, a variable attenuation circuit is provided between the distribution element and the amplifier.

With the above structure, the variable attenuation circuit is provided between the distribution element and the amplifier. Therefore, in addition to the effect of the above configuration, by appropriately controlling the variable attenuation circuit according to the input signal level, the signal input level to the tuner unit on the distribution output terminal side is limited to the optimum fixed level or less. be able to. Further, when the input signal level is high, the distortion generated in the amplifier can be reduced.

In addition to the above configuration, the signal processing apparatus of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input, and a received signal input from the input section are provided in each tuner unit. And a distribution element for distributing to the transformer, wherein the distribution element is a branching device having an input terminal and an output terminal that are one side of the transformer, and a branch terminal that is the other side of the transformer. The input section of the switch is connected to the input section, and at least one tuner unit covered with the distribution unit and one metal casing is connected to one of the output terminal and the branch terminal of the branching unit. Is characterized by.

With the above structure, the distribution element is a branching device having an input terminal and an output terminal on one side of the transformer and a branching terminal on the other side of the transformer. Therefore, of the output terminal and the branch terminal of the branch device, from the terminal to which the distribution unit and the tuner unit covered with one metal housing are connected,
Crosstalk to the other terminal is small.

Therefore, in addition to the effects of the above configuration, each tuner unit can receive a signal well. For example, a tuner unit A includes an oscillator that generates an oscillation signal and mixes the oscillation signal with the reception signal input from the input unit to frequency-convert the reception signal. Even if the signal enters the reception frequency band of another tuner unit B, the signal from the branch terminal of the above branching device is input to the tuner unit A, and the tuner unit B is output from the output terminal of the above branching device. By inputting the signal of (3), it is possible to reduce crosstalk from the oscillator of the tuner unit A to the tuner unit B. Therefore, the tuner unit B can satisfactorily receive the signal.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of this embodiment, including the entire front end section 1 of an STB (Set Top Box). The operation of each block in FIG. 1 is the same as that in FIG. 1
1 to 20 are 111 to 12 of FIG. 22, respectively.
It is the same as 0. 21 to 31 are respectively shown in FIG.
121 to 131. 32 to 34
Are the same as 132 to 134 in FIG. 22, respectively. 41, 42, and 51 are 141 and 41 of FIG. 22, respectively.
It is the same as 142 and 151.

The front end module 2 (signal processing device) is a tuner unit 102 for data reception shown in FIG.
The distribution unit 104 and the distribution unit 104 are integrated into one unit, and these two units are housed in one metal housing. The video receiving tuner unit 3 is the same as the video receiving tuner unit 103 in FIG. 22, and is housed in a metal housing separate from the front end module 2. Examples of metals that can be used for these metal housings include turn sheets and tin plates. That is, the high pass filter 41 and the distributor 4
A distribution unit is composed of 2, and a data receiving tuner unit is composed of the members 11 to 19. The distribution unit includes two or more signals (here, a signal for the video reception tuner unit 3 and a signal for the data reception tuner unit in the front end module 2) received through one communication path.
The received signal including the signal is separated into each signal, and each separated signal is converted into a tuner unit (here,
It is sent to the video receiving tuner unit 3 and the data receiving tuner unit).

A high-pass filter (HPF) 41 and a low-pass filter (LPF) 51 constitute a diplexer.

Reference numeral 42 is a distributor (distribution element) having a distribution function. This has a structure as shown in FIG.
That is, the distributor 61 (the distributor 42) has the impedance transformer 62 and the distribution circuit 63, and distributes the signal input from the input terminal IN to the distribution terminals D1 and D2, that is, outputs it to both simultaneously. have.

2 and 3 show an example of this embodiment.
The example of the outer shape of the front end module is shown. The input signal is input from the input terminal 2a in the figure, internally distributed, and then output from the distribution output terminal 2b or 2c in the figure. The distribution output terminal 2b adopts RCA PHNO JACK as a connector having a coaxial structure. The distribution output terminal 2c is MIN as a connector having a coaxial structure.
I JACK is adopted.

2 and 3 are just examples.
The embodiment of the present invention does not limit the types and positional relationships of the input terminals and the distribution output terminals, and the shape of the module housing.

The high-frequency units used in the configuration example shown in FIG. 1 are two, a front-end module and a video receiving tuner unit. In the conventional technique of FIG. 22,
The distribution unit, the data receiving tuner unit, and the video receiving tuner unit were three units, but this configuration can reduce the number to two, which leads to cost reduction of the entire set.

Further, there are two conventional connection points between the high frequency units (between the distribution unit and the data receiving unit,
The number is reduced from one (between the distribution unit and the video receiving unit) to one (between the front end module and the video receiving tuner unit), and it is possible to reduce the evaluation content in combination.

Furthermore, due to the connection between the front end module and the video receiving tuner unit,
The deterioration of electrical performance is avoided by adopting a connector having a coaxial structure represented by FIGS. 2 and 3 as a distribution output terminal of the front end module.

FIG. 4 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 4 will be described below. Note that description of the same points as in FIG. 1 will be omitted.

The front end shown in FIG.
It is used when it is necessary to simultaneously transmit two different upstream signals (1, 2) (transmission signals) from the input terminal (I) to the communication path. The upstream signals (1, 2) are modulated by a modulator 35 (transmission signal input section) and a modulator 37 (transmission signal input section), amplified by amplifiers 36, 38, respectively, and then combined by a combiner 52 in the front end module. After being combined by the (combining unit) and subjected to band limitation by the low-pass filter 51, it is transmitted from the input terminal (I). That is, the modulator 35, the modulator 37, and the amplifier 3
6, the amplifier 38, the coupler 52, and the low-pass filter 51 form a transmission path. With this configuration, it is possible to transmit two different upstream signals at exactly the same time.

FIG. 5 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 5 will be described below. Note that description of the same points as in FIG. 1 will be omitted.

The front end shown in FIG.
It is used when it is necessary to selectively transmit two different upstream signals (1, 2) from the input terminal (I). The upstream signals (1, 2) are
It is modulated by modulators 35 and 37, and amplified by amplifier 36 and amplifier 38, respectively. Then, the route corresponding to the required upstream signal is switched by the switch 53 (switching unit). The transmitted signal is band-limited by the low-pass filter 51 via the switch, and then transmitted from the input terminal (I).

When the coupler of FIG. 4 is used, theoretically 3
Although a loss of dB occurs, when using a switch,
The loss can theoretically be 0 dB. For this reason,
The output level required by the amplifiers 36 and 38 can be reduced by about 3 dB. With this configuration, it is possible to selectively transmit two different upstream signals. Further, it is possible to eliminate the loss that has occurred when using the coupler.

FIG. 6 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 6 will be described below. Note that description of the same points as in FIG. 1 will be omitted.

In the front end shown in FIG. 6, the set is
Two different upstream signals (1, 2) need to be transmitted simultaneously from the input terminal (I), and
This is used when the bands of the upstream signals (1, 2) are different from each other. The upstream signals (1, 2) are respectively modulated by the modulator 35 and the modulator 37, amplified by the amplifier 36 and the amplifier 38, and then optimized in the front-end module.
4. After being band-limited by the low-pass filter 55, they are combined by the combiner 56 (combining section) and transmitted from the input terminal (I).

With this configuration, two different upstream signals can be transmitted at exactly the same time, and at the same time, optimum band limitation can be applied to each signal by separate low-pass filters.

FIG. 7 shows a block diagram of an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 7 will be described below. Note that description of the same points as in FIG. 1 will be omitted.

The front end shown in FIG.
It is used when it is necessary to selectively transmit two different upstream signals (1, 2) from the input terminal (I) and when the bands of the upstream signals (1, 2) are different from each other. is there. The upstream signals (1, 2) are supplied to the modulator 35 and the modulator 37, respectively.
After being modulated by, and amplified by the amplifier 36 and the amplifier 38, the band is limited by the optimum low pass filters 54 and 55 in the front end module. Then, the switch 57 (switching unit) switches the path according to the required upstream signal. The signal to be transmitted is transmitted from the input terminal (I) via the switch 57.

When the coupler of FIG. 6 is used, theoretically 3
Although a loss of dB occurs, when using a switch,
The loss can theoretically be 0 dB. For this reason,
The output level required by the amplifiers 36 and 38 can be reduced by about 3 dB. With this configuration, two different upstream signals can be selectively transmitted, and at the same time, optimum band limitation can be applied to each signal by separate low-pass filters. Also,
The loss that has occurred when using the coupler can be eliminated.

FIG. 8 is an example of this embodiment and shows an example of the outer shape of the front end module. The input signal is input from the input terminal 2a in the drawing, internally distributed, and then output from the distribution output terminal 2d in the drawing. The distribution output terminal 2d adopts a coaxial cable with RCA PIN PLUG as a coaxial cable with a connector.

With this configuration, a coaxial cable with a connector typified by FIG. 8 is adopted as the distribution output terminal of the front end module, which is concerned about the deterioration of the electrical performance which may be caused by the connection between the front end module and the video receiving tuner unit. I am avoiding it. not only that,
Coaxial cables used for connecting between units are not required, unit connection is easy when mounting the set, and the unit supplier guarantees the performance including the coaxial cable, making it easy to design and evaluate the set. Can be

Note that FIG. 8 is merely an example, and the embodiment of the present invention does not limit the types and positional relationships of the input terminals and the distribution output terminals, and the module housing shape.

FIG. 9 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 9 will be described below. Note that description of the same points as in FIG. 1 will be omitted. The high-pass filter 41, the distributor 42, and the amplifier 43 form a distribution unit.

The downstream signal (received signal) input from the input terminal (I) is band-limited by the high-pass filter 41 and then amplified by the amplifier 43. This signal is distributed by the distributor 42 and sent to each selective reception tuner. Here, when the amplification amount in the amplifier 43 is set to be the same as the loss amount in the distributor 42, the signal input level to each selective reception tuner is set to the conventional individual level shown in FIGS. It is possible to set the same level as that of the set, and it is possible to use the selective reception tuner that has been evaluated conventionally as it is.

Noise figure (noise characteristic) of the set total (entire front end portion of STB) is the noise figure of the selective reception tuner when the amplifier 43 is not provided.
The loss in the distributor 42 is added to the above, but by adding the amplifier 43, the total Noise Figu
re can be improved.

With this configuration, the selective reception tuner which has been evaluated conventionally can be used as it is. In addition, the noise figure of the total set can be improved.

FIG. 10 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 10 will be described below. Note that FIG.
Descriptions of the same points as those of the above are omitted. High-pass filter 41, distributor 42, amplifier 43, and variable attenuator 4
A distribution unit is constituted by 4.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41 and then amplified by the amplifier 43. When the input signal level is above a certain level, this signal is attenuated by the variable attenuator 44 according to the level, distributed by the distributor 42, and sent to each selective reception tuner.

With this configuration, the signal input level to each selective reception tuner can be limited to a certain level or less, and the variable attenuating circuit (not shown) conventionally provided in each selective reception tuner can be eliminated. .

FIG. 11 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 11 will be described below. Note that FIG.
Descriptions of the same points as those of the above are omitted. High-pass filter 41, distributor 42, amplifier 43, and variable attenuator 4
A distribution unit is constituted by 4.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41 and then attenuated by the variable attenuator 44 according to the level when the input signal level is above a certain level. It This signal is amplified by the amplifier 43, distributed by the distributor 42, and sent to each selective reception tuner. Amplifier 4
Since the variable attenuator suppresses the signal level to a certain level or less before the signal is input to 3, the signal distortion generated in the amplifier 43 can be reduced.

With this configuration, the signal input level to each selective reception tuner can be limited to a certain level or less, and it is possible to reduce the variable attenuating circuit conventionally provided in each selective reception tuner. In addition, it is possible to reduce the distortion generated in the amplifier when a strong input signal is input.

FIG. 12 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 12 will be described below. Note that FIG.
Descriptions of the same points as those of the above are omitted. The high-pass filter 41, the distributor 42, and the amplifier 45 form a distribution unit.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41 and then distributed by the distributor 42. Of the outputs of the distributor 42, the output to the data receiving tuner unit is sent to the tuner as it is. The output to the video receiving tuner unit is further amplified by the amplifier 45 and output.

With this configuration, the level of output to the video receiving tuner unit can be set independently of the data receiving tuner unit, so that the optimum level can be obtained.

In general, the tuner unit is set to the optimum gain by itself. Therefore, when the distribution is performed by the distributor 42 as described above, there is a possibility that the distributor 42 may cause a gain loss and the total gain may be insufficient as it is. On the other hand, in the configuration as shown in FIG. 12, the output to the video receiving tuner unit is further amplified and output by the amplifier 45, so that the occurrence of such a total gain shortage can be suppressed. .

FIG. 13 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 13 will be described below. Note that FIG.
Descriptions of the same points as those in 2 will be omitted. The high-pass filter 41, the distributor 42, the amplifier 45, and the variable attenuator 46 constitute a distribution unit.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41 and then distributed by the distributor 42. Of the outputs of the distributor 42, the output to the data receiving tuner unit is sent to the tuner as it is. The output to the video receiving tuner unit is further amplified by the amplifier 45, and when the signal level is above a certain level, it is attenuated by the variable attenuator 46 according to the level and output.

With this configuration, the level of output to the video receiving tuner unit can be set below the optimum level, which is unrelated to the data receiving tuner unit.

Further, it becomes possible to eliminate a variable attenuation circuit (not shown) which is conventionally provided in the video receiving tuner.

FIG. 14 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 14 will be described below. Note that FIG.
Descriptions of the same points as those in 2 will be omitted. The high-pass filter 41, the distributor 42, the amplifier 45, and the variable attenuator 46 constitute a distribution unit.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41 and then distributed by the distributor 42. Of the outputs of the distributor 42, the output to the data receiving tuner unit is sent to the tuner as it is. When the signal level is above a certain level, the output to the video receiving tuner unit is further attenuated by the variable attenuator 46, amplified by the amplifier 45, and output.

With this configuration, the level of output to the video receiving tuner unit can be set below the optimum level irrelevant to the data receiving tuner unit.
In addition, it is possible to eliminate the variable attenuation circuit (not shown) that is conventionally provided in the video receiving tuner unit.

In addition to these, since the variable attenuator suppresses the signal level to a certain level or less before the signal is input to the amplifier 45, the distortion of the signal generated in the amplifier 45 can be reduced.

FIG. 15 is a block diagram showing an example of this embodiment, including the entire front end portion of the STB. The operation of FIG. 15 will be described below. Note that FIG.
Descriptions of the same points as those of the above are omitted. The high-pass filter 41 and the branching device 47 form a distribution unit.

The downstream signal input from the input terminal (I) is band-limited by the high-pass filter 41, and then input to the input terminal 47a of the branching device 47 (distribution element), and the data receiving tuner is input to the branching terminal 47b. It is output to the unit and is output to the output to the video receiving tuner unit through the output terminal 47c.

The branching device 47 is an element having a distribution function (distribution element). This has a structure as shown in FIGS. FIG. 18 is a simplified version of the configuration of FIG. That is, the branching device 65 (corresponding to the branching device 47)
Has a function of distributing the signal input from the input terminal IN (corresponding to 47a) to the output terminal OUT (corresponding to 47c) and the branch terminal BR (corresponding to 47b), that is, simultaneously outputting to both. ing. In the figure, T1 and T2 are transformers, R and r are resistors, e and e'are voltages, i1 and i2,
i'2 is an electric current.

Input terminal IN (47a) and output terminal O
The UT (47c) is one side of the transformer T1 and the branch terminal BR (47b) is the other side of the transformer T1.
Output terminal OUT (47c) and branch terminal BR (47
The distribution unit and the tuner unit covered with one metal housing are connected to one of the two sides of b). That is,
Here, a data receiving tuner, which is a tuner unit covered with a distribution unit and one metal housing, is connected to the branch terminal BR (47b), and the output terminal OU is connected.
To T (47c), a video reception tuner unit 3 which is a tuner unit which is not covered with one metal housing and is connected as a separate housing to the distribution unit is connected. Conversely, the output terminal OUT may be connected to the distribution unit and the tuner unit covered with one metal housing.

Generally, the oscillation frequency band of the data receiving tuner unit is 134.75 MHz to 90.
0.75MHz, the reception frequency band of the video signal is 5
Since it is from 5.25 MHz to 859.25 MHz, the oscillation frequency band of the data receiving tuner unit falls within the reception frequency band of the video signal. On the other hand, in general, the oscillation frequency band of the video reception tuner unit is 1 GHz or more, and the reception frequency band of the data signal is 88 MHz to 860.
Since it is MHz, the oscillation frequency band of the tuner unit for receiving video does not fall within the reception frequency band of the data signal. As described above, since the oscillation frequency of the data receiving tuner unit falls within the reception frequency band of the video signal,
The leakage of the oscillation signal interferes with the video receiving tuner. On the other hand, since the oscillation frequency of the video receiving tuner unit is outside the receiving frequency band of the data signal, it does not interfere with the data receiving tuner unit. Therefore, in this configuration, the isolation (crosstalk) from the data receiving tuner unit to the video receiving tuner unit is made smaller than the opposite.
The isolation from the branch terminal 47b of the branch circuit 47 to the output terminal 47c is the same as that between the output terminals of the distribution circuit,
It can be made smaller in comparison. Therefore, with this configuration, the isolation from the data receiving tuner unit to the video receiving tuner can be made small.

In the above description using FIG. 1 and the like, there are two tuner units, one of which (a data receiving tuner unit) is stored in the same metal housing as the distribution unit, and the other one. One (video receiving tuner unit) was prepared separately from the distribution unit and was connected to the distribution output terminal of the distribution unit. Here, there are two or more tuner units distributed from one distribution unit, and one or more of the tuner units are housed in the same metal housing as the distribution unit,
The remaining tuner units (also one or more) may be prepared separately from the distribution unit and connected to the distribution output terminals of the distribution unit.

According to the present invention, a front end module used in a digital STB capable of simultaneously receiving a plurality of modulated signals is provided with a diplexer which is directly connected to a signal input terminal and separates an upstream signal and a downstream signal. ,And,
It has a distribution means for distributing the downstream signal, and a tuner function for selectively receiving one of the distributed signals,
A module that distributes and outputs the other distributed signal to another selective reception tuner, and can be configured such that a connector having a coaxial structure is adopted as the latter distribution output terminal.

According to the above configuration, the number of high frequency units required for the set is reduced from three to two, which not only has a cost merit, but also the connection between the high frequency units is one from two. Therefore, the evaluation period can be shortened. Further, by adopting a connector having a coaxial structure as the output terminal, it is possible to stabilize the impedance of the output terminal and suppress deterioration of electrical performance due to connection of the unit.

Further, the present invention can be configured so as to include a combiner for combining a plurality of upstream signals in the upstream path after the diplexer.

According to the above configuration, a plurality of upstream signals can be transmitted at the same time.

Further, the present invention can be configured so that a switch for selecting a required signal from a plurality of upstream signals is provided on the upstream path after the diplexer.

According to the above arrangement, in a system using a plurality of upstream signals and transmitting selected upstream signals, the loss of the upstream signals can be reduced as compared with the case where a combiner is used. You can

Further, the present invention is a front-end module used in a digital STB capable of receiving a plurality of modulated signals at the same time, which is a front end module, which is directly connected to a signal input terminal, for coupling a plurality of upstream signals, and a down converter. A tuner function that includes a high-pass filter that passes a stream signal and a plurality of low-pass filters that are connected to the combiner and have different bands, and a distribution unit that distributes a downstream signal, and selectively receives one of the distributed signals. And a module for distributing and outputting the other distributed signal to another selective receiving tuner, and can be configured such that a connector having a coaxial structure is adopted as the latter distribution output terminal.

According to the above construction, not only the number of high frequency units necessary for the set is reduced, the evaluation period is shortened, the high frequency units are connected easily by adopting the connector having the coaxial structure, but also the different frequency bands are increased. Stream signals can be simultaneously transmitted while band limiting is performed by an optimum low-pass filter.

Further, the present invention is a front end module used in a digital STB capable of receiving a plurality of modulated signals at the same time, and selects a necessary signal from a plurality of upstream signals directly connected to a signal input terminal. A tuner that includes a switch and a high-pass filter that passes a downstream signal, and a plurality of low-pass filters that are connected to the switch and have different bands, and that includes a distributor that distributes the downstream signal, and that selectively receives one of the distributed signals. A module that has a function and distributes and outputs the other distributed signal to other selective reception tuners, which can be configured by adopting a connector having a coaxial structure as the latter distribution output terminal. .

According to the above construction, not only the number of high frequency units required for the set is reduced, the evaluation period is shortened, the high frequency units are connected easily by adopting the connector having the coaxial structure, but also a plurality of different bands are used. In a system that uses a stream signal, and when the upstream signal is not transmitted at the same time, it is possible to transmit while limiting the bandwidth by the optimum low-pass filter, and compared to the case where a combiner is used, Signal loss can be reduced.

The present invention also provides a distributed output terminal,
It can be configured as if a coaxial cable with a connector was adopted.

According to the above configuration, the set evaluator does not need to prepare a coaxial cable with a connector, and the unit supplier guarantees the performance including the cable. Can be easy.

Further, the present invention can be configured such that an amplifier is provided between the diplexer (or high pass filter) and the distribution means.

According to the above configuration, by guaranteeing the loss due to the distribution, it becomes possible to set the signal input level to each selective reception tuner to the same level as the conventional individual set, which is evaluated in the past. The selected selective reception tuner can be used as it is.

Moreover, the noise figure of the set total can be improved.

Further, the present invention can be configured so that a variable attenuation circuit is provided between the amplifier and the distribution circuit.

According to the above configuration, by appropriately controlling the variable attenuator circuit according to the input signal level, the signal input level to each selective reception tuner can be limited to a certain level or less, and each selective reception tuner can be controlled. It is possible to eliminate the variable attenuation circuit that is conventionally provided in each tuner.

Further, the present invention can be configured so that a variable attenuation circuit is provided between the diplexer (or high pass filter) and the amplifier.

According to the above configuration, by appropriately controlling the variable attenuator circuit according to the input signal level, the signal input level to each selective reception tuner can be limited to a certain level or less, and each selective reception tuner can be controlled. It is possible not only to reduce the variable attenuation circuit conventionally provided in each tuner, but also to reduce the distortion generated in the amplifier at the time of a strong input signal.

Further, the present invention can be configured such that an amplifier is provided in the path from the distribution means to the distribution output terminal.

With the above arrangement, the signal input level to the receiving tuner on the distribution output terminal side can be set to the optimum level.

Further, the present invention can be configured such that a variable attenuator circuit is provided in the path from the amplifier to the distribution output terminal.

According to the above configuration, the variable attenuator circuit is appropriately controlled in accordance with the input signal level, so that the signal input level to the receiving tuner on the distribution output terminal side is limited to the optimum fixed level or less. it can.

Further, the present invention can be configured so that a variable attenuation circuit is provided between the distribution means and the amplifier.

According to the above configuration, the variable attenuation circuit is appropriately controlled according to the input signal level, so that the signal input level to the receiving tuner on the distribution output terminal side is limited to the optimum fixed level or less. In addition, it is possible to reduce the distortion generated in the amplifier when a strong input signal is input.

Further, the present invention can be configured so as to have branching means instead of the distributing means for distributing the downstream signal.

Usually, the transmission frequency of the data receiving tuner falls within the reception frequency band, and therefore the isolation from the data receiving tuner to the video receiving tuner needs to be made larger than the opposite. Since the isolation from the branch terminal of the branch circuit to the output terminal can be made larger than that between the output terminals of the distribution circuit, if the branch terminal is used for the output to the data receiving tuner, the data receiving tuner can be used for video receiving. Great isolation to the tuner.

[0136]

As described above, in the signal processing device of the present invention, at least one of the tuner units and the distribution unit are covered with one metal casing, and the other tuner units are connected to the distribution unit. This is a configuration including a distribution output terminal for performing.

As a result, the distribution unit and the tuner unit housed in the same housing as the distribution unit can be adjusted accurately and precisely at the time of manufacture. Also,
With the distributed output terminal, the tuner unit used so far can be used in the future. Therefore, there is an effect that both the compatibility problem of the new device and the versatility that can be used in the conventional device can be compatible.

In addition to the above configuration, the signal processing device of the present invention is arranged such that the distribution unit and the tuner unit covered by a single metal casing are arranged such that the distribution unit outputs signals other than cable television image signals. Is output, and the distribution output terminal outputs a cable television video signal.

As a result, in an environment in which the cable television receiving device is already installed, the cable television receiving device can be used to receive the cable television broadcast while making use of the cable television receiving device.
The effect that other communication can be used is produced.

In addition to the above-mentioned structure, the signal processing apparatus of the present invention has a plurality of transmission signal input sections to which two or more transmission signals are respectively input, and the above-mentioned transmission signal input section. This is a configuration including a transmission path for transmitting at least one of the two or more transmission signals to the communication path.

As a result, at least one of the two or more transmission signals is transmitted to the communication path. Therefore, in addition to the effect of the above configuration, there is an effect that at least one of the two or more transmission signals can be transmitted using the existing communication path.

Further, the signal processing device of the present invention has, in addition to the above configuration, a configuration including a coupling unit for coupling two or more of the transmission signals as a component for transmission to the communication path.

Thus, in addition to the effects of the above configuration, there is an effect that both of two or more transmission signals can be simultaneously transmitted by utilizing the existing communication path.

Further, the signal processing apparatus of the present invention has, in addition to the above configuration, a low pass filter for each transmission path between each of the transmission signal input sections and the coupling section.

As a result, in addition to the effects of the above configuration, even if the bands of the plurality of transmission paths are different from each other, it is possible to provide an optimum low-pass filter for each.

Further, the signal processing apparatus of the present invention has, in addition to the above-mentioned configuration, a switching section for switching the transmission signal to be transmitted to the communication path.

As a result, by switching two or more transmission signals, one of them is transmitted to the communication path. Therefore, in addition to the effect of the above configuration, there is an effect that it is possible to transmit while switching two or more transmission signals by using an existing communication path.

Further, the signal processing device of the present invention has, in addition to the above configuration, a low pass filter for each transmission path between each of the transmission signal input sections and the coupling section.

As a result, in addition to the effect of the above configuration, even if the bands of the plurality of transmission paths are different from each other, it is possible to provide an optimum low-pass filter for each.

The signal processing device of the present invention has, in addition to the above configuration, a coaxial cable with a connector provided at the distribution output terminal.

As a result, in addition to the effects of the above configuration, it is possible to accurately and precisely adjust the compatibility of each member in the signal processing device including the coaxial cable with the connector at the time of manufacturing. Has the effect of becoming.

In addition to the above configuration, the signal processing device of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input and a received signal input from the input section are provided in each tuner unit. A distribution element for distributing to the input device and an amplifier is provided between the input section and the distribution element.

As a result, in addition to the effect of the above configuration, it is possible to compensate for the loss of the signal level due to the distribution element.

Further, the signal processing device of the present invention has, in addition to the above configuration, a variable attenuation circuit provided between the amplifier and the distribution element.

As a result, in addition to the effects of the above configuration, it is possible to eliminate the need to provide a variable attenuation circuit for each tuner unit when limiting the signal input level to each tuner unit below a certain level. Produce an effect.

Further, the signal processing device of the present invention has, in addition to the above configuration, a variable attenuation circuit provided between the input section and the amplifier.

As a result, in addition to the effects of the above configuration, it is possible to eliminate the need to provide a variable attenuation circuit for each tuner unit when limiting the signal input level to each tuner unit below a certain level. When the input signal level is high, it is possible to reduce the distortion generated in the amplifier.

In addition to the above configuration, the signal processing device of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input, and a received signal input from the input section are provided in each tuner unit. And a distribution element for distributing the signal to the distribution output terminal, and an amplifier is provided between the distribution element and the distribution output terminal.

Thus, in addition to the effect of the above configuration, the signal input level to the tuner unit on the distribution output terminal side can be set to the optimum level.

In addition to the above-mentioned structure, the signal processing device of the present invention is characterized in that, between the amplifier and the distribution output terminal,
This is a configuration provided with a variable attenuation circuit.

Thus, in addition to the effects of the above configuration, by appropriately controlling the variable attenuator circuit according to the input signal level, the signal input level to the tuner unit on the distribution output terminal side can be set to an optimum fixed level or less. The effect that it can be limited is exhibited.

Further, the signal processing device of the present invention has a configuration in which, in addition to the above configuration, a variable attenuation circuit is provided between the distribution element and the amplifier.

Thus, in addition to the effects of the above configuration, by appropriately controlling the variable attenuator circuit according to the input signal level, the signal input level to the tuner unit on the distribution output terminal side can be set to an optimum fixed level or less. It is possible to reduce the distortion generated in the amplifier when the input signal level is high.

In addition to the above configuration, the signal processing apparatus of the present invention is configured such that, in the distribution unit, an input section to which the received signal is input, and a received signal input from the input section are provided in each tuner unit. And a distribution element for distributing to the transformer, wherein the distribution element is a branching device having an input terminal and an output terminal that are one side of the transformer, and a branch terminal that is the other side of the transformer. The input unit is connected to the input unit, and at least one tuner unit covered with the distribution unit and one metal housing is connected to one of the output terminal and the branch terminal of the branching unit. Is.

As a result, the crosstalk from the branch terminal of the branch device to the output terminal of the branch device is small. Therefore, in addition to the effect of the above configuration, there is an effect that each tuner unit can receive a signal well.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a front end section of an STB including a front end module according to the present invention.

FIG. 2 is a plan view showing a configuration example of a front end module according to the present invention.

FIG. 3 is a plan view showing another configuration example of the front end module according to the present invention.

FIG. 4 is a block diagram showing another configuration example of the front end section of the STB including the front end module according to the present invention.

FIG. 5 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 6 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 7 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 8 is a plan view showing still another configuration example of the front end module according to the present invention.

FIG. 9 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 10 is a block diagram showing still another configuration example of the front end section of the STB including the front end module according to the present invention.

FIG. 11 is a block diagram showing still another configuration example of the front end section of the STB including the front end module according to the present invention.

FIG. 12 is a block diagram showing still another configuration example of the front end section of the STB including the front end module according to the present invention.

FIG. 13 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 14 is a block diagram showing still another configuration example of the front end portion of the STB including the front end module according to the present invention.

FIG. 15 is a block diagram showing still another configuration example of the front end section of the STB including the front end module according to the present invention.

FIG. 16 is a block diagram showing a configuration example of a distributor used in the front end module according to the present invention.

FIG. 17 is a block diagram showing a configuration example of a branching device used in the front end module according to the present invention.

FIG. 18 is a block diagram showing a configuration example of a branching device used in the front end module according to the present invention.

FIG. 19 is a block diagram showing a configuration example of a front end unit of a conventional digital CATV STB.

FIG. 20 is a block diagram showing a configuration example of a front end section of a conventional digital CATV STB.

FIG. 21 is a block diagram showing a configuration example of a front end portion of a conventional cable modem.

FIG. 22 is a block diagram showing a configuration example of a front end section of a conventional digital STB capable of simultaneously receiving a plurality of modulated signals.

[Explanation of symbols]

1 Front end part 2 Front-end module (signal processing device) 2a input terminal 2b Distribution output terminal 2c Distribution output terminal 2d distribution output terminal 3 Video receiving tuner unit 11 amplifier 12 bandpass filter 13 amp 14 bandpass filter 15 mixer 16 oscillators 17 amp 18 SAW filter 19 amplifier 20 QAM demodulation circuit 21 amplifier 22 mixer 23 oscillators 24 band pass filter 25 amps 26 bandpass filter 27 mixer 28 oscillators 29 amplifier 30 bandpass filter 31 Demodulation circuit 32 modulator 33 amplifier 34 modulator 35 Modulator (transmission signal input section) 36 amplifier 37 Modulator (transmission signal input section) 38 amplifier 41 High Pass Filter 42 distributor (distribution element) 43 amplifier 44 Variable attenuator 45 amp 46 Variable attenuator 47 Divider (distribution element) 47a input terminal 47b Branch terminal 47c output terminal 51 low pass filter 52 Coupler (Coupling part) 53 switch (switching part) 54 Low-pass filter 55 Low-pass filter 56 Combiner (Coupling part) 57 switch (switching part) 61 Distributor (Distribution element) 62 Impedance transformer 63 distribution circuits 65 Branch (Distributor)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5C025 AA17 AA20 AA26 DA01                 5C056 FA01 HA01 HA04 HA14 HA15                       JA01 JA06                 5C064 BA01 BC13 BC14 BC20 BC27                       BD08                 5K016 CC05 DA03 EA03 GA07

Claims (15)

[Claims] 1. A signal provided with a distribution unit for separating a received signal including two or more signals received through one communication path into respective signals and sending the separated signals to a tuner unit corresponding to each signal. In the processing device, at least one of the tuner units and the distribution unit are covered with one metal casing, and a distribution output terminal for connecting the other tuner unit and the distribution unit is provided. A characteristic signal processing device. 2. The tuner unit covered with the distribution unit and one metal housing, the distribution unit outputs a signal other than a cable TV video signal, and the distribution output terminal outputs a cable TV video signal. The signal processing device according to claim 1, wherein the signal processing device outputs the signal. 3. A plurality of transmission signal input sections to which two or more transmission signals are respectively input, and at least one of the two or more transmission signals input to the transmission signal input section is used for the communication. The signal processing device according to claim 1, further comprising a transmission path for transmitting to the path. 4. The signal processing apparatus according to claim 3, further comprising a coupling unit that couples two or more of the transmission signals as a signal to be transmitted to the communication path. 5. The signal processing apparatus according to claim 4, further comprising a low-pass filter for each transmission path between each of the transmission signal input sections and the coupling section. 6. A switching unit for switching the transmission signal to be transmitted to the communication path.
The signal processing device described. 7. The signal processing device according to claim 6, further comprising a low-pass filter provided for each transmission path between each of the transmission signal input sections and the switching section. 8. The signal processing device according to claim 1, wherein the distribution output terminal is provided with a coaxial cable with a connector. 9. The distribution unit comprises an input section for receiving the reception signal and a distribution element for distributing the reception signal input from the input section to each tuner unit, the input section and the distribution section. The signal processing device according to claim 1, further comprising an amplifier provided between the signal processing device and the element. 10. A variable attenuation circuit is provided between the amplifier and the distribution element.
The signal processing device described. 11. A signal processing apparatus according to claim 9, further comprising a variable attenuation circuit provided between the input section and the amplifier. 12. The distribution unit comprises an input section for receiving the received signal and a distribution element for distributing the received signal input from the input section to each tuner unit. The signal processing device according to claim 1, further comprising an amplifier provided between the signal processing device and the output terminal. 13. The signal processing device according to claim 12, further comprising a variable attenuation circuit provided between the amplifier and the distribution output terminal. 14. A variable attenuation circuit is provided between the distribution element and the amplifier.
2. The signal processing device according to item 2. 15. The distribution unit comprises an input section for receiving the reception signal and a distribution element for distributing the reception signal input from the input section to each tuner unit, wherein the distribution element is a transformer. A branching device comprising an input terminal and an output terminal on one side of the transformer, and a branching terminal on the other side of the transformer, wherein the input section is connected to the input terminal of the branching device. 2. The signal processing device according to claim 1, wherein at least one tuner unit covered with the distribution unit and one metal housing is connected to one of the output terminal and the branch terminal of the.