booster

Abstract

To provide a technique for suppressing mistake in switch setting required for change when changing an input signal supply source with resect to a booster.SOLUTION: A signal processing circuit 41 outputs an input signal DN1 as it is to a subsequent stage as an intermediate signal DN if a switch SW21 is set to a CATV mode. The signal processing circuit 41 outputs a signal in an UHF signal frequency band from the input signal DN1 to the subsequent stage as the intermediate signal DN if the switch SW21 is set to a non-powered UHF mode or a powered UHF mode. The signal processing circuit 41 feeds power to an external device connected between a terminal T1 and a UHF antenna through the terminal T1 if the switch SW21 is set to the powered UHF mode.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a booster that amplifies UHF signals and CATV signals. [Background Art]

[0002] A communal reception booster compatible with UHF-band television broadcasting radio waves and CATV is used by being installed in a distribution board or the like. The booster is configured to be compatible with signals of different frequency bands by switching its operation mode between a UHF mode for receiving UHF-band television broadcasting radio waves and a CATV mode for receiving CATV. Furthermore, in the UHF mode, the booster is configured such that whether to supply power to a preamplifier inserted between the booster and an antenna can be switched.

[0003] Non-Patent Document 1 describes a booster configured to perform switching of the operation mode and switching of whether to supply power to the preamplifier, respectively, using individually provided switches for operation. [Prior Art Literature] [Non-Patent Literature]

[0004] [Non-Patent Document 1] MASPRO Denko Co., Ltd., "MASPRO General Catalog 2022", p.76 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Consider a case where in a terrestrial television broadcasting reception system using a booster connected to receive a reception signal from a UHF antenna and also set to supply power to a preamplifier, the settings are changed to operate by inputting a signal from a CATV system.

[0006] In this case, with conventional boosters, it is necessary not only to switch the operating mode switch from UHF to CATV, but also to switch the power supply to the preamplifier from powered on to powered off.

[0007] Typically, signals from the CATV system are supplied to the booster via a surge protector. Between the surge protector and the booster, external devices consisting of passive components that do not require power supply, such as filters and attenuators, may be inserted, depending on the booster's installation environment.

[0008] Furthermore, consider the case where, during the switching process from UHF to CATV, only the switch for setting the operating mode is toggled, and the switch for setting whether or not power is supplied is not toggled. In this case, a large current could flow through the resistors and other components of the aforementioned external device, causing the external device to overheat and potentially leading to reduced functionality or failure.

[0009] One aspect of this disclosure is the provision of a technique to prevent errors in switch settings that may occur when changing the source of the input signal to a booster. [Means for solving the problem]

[0010] One aspect of the present disclosure is a booster comprising an input terminal, a signal processing circuit, an amplification circuit, an output terminal, and a mode setting switch. The input terminal receives a UHF signal or a CATV signal. The signal processing circuit is configured to process the input signal received from the input terminal. The amplification circuit is configured to at least amplify the intermediate signal output from the signal processing circuit. The output terminal outputs the signal processed by the amplification circuit. The mode setting switch is used to set the operating mode of the signal processing circuit to one of CATV mode, unpowered UHF mode, or powered UHF mode. When the mode setting switch is set to CATV mode, the signal processing circuit outputs the input signal as an intermediate signal. When the mode setting switch is set to unpowered UHF mode, the signal processing circuit outputs a signal belonging to the frequency band of the UHF signal extracted from the input signal as an intermediate signal. The signal processing circuit is configured such that, when the mode setting switch is set to the powered UHF mode, it outputs a signal belonging to the frequency band of the UHF signal extracted from the input signal as an intermediate signal, and also supplies power to an external device connected between the input terminal and the UHF antenna via the input terminal.

[0011] With this configuration, the operating mode can be switched, and the power supply to the input terminal can be switched using the mode setting switch. Therefore, when changing the booster from powered UHF mode to CATV mode, it is possible to remember to stop the power supply to the input terminal. As a result, it is possible to prevent unnecessary power supply to external devices that do not require power, which would cause the external devices to overheat and lead to a decrease in the functionality or failure of the system that uses the booster as a component.

[0012] In one aspect of this disclosure, the signal processing circuit may include a UHF filter, a UHF power supply circuit, a first control line, a second control line, a third control line, and a path switching circuit. The UHF filter is configured to extract signals in the UHF frequency band. The UHF power supply circuit is configured to apply a power supply to the input terminal. The first control line is configured to pass the input signal input to the signal processing circuit directly to the next stage. The second control line is configured to output the input signal to the next stage via the UHF filter. The third control line is configured to output the input signal to the next stage via the UHF filter and to activate the UHF power supply circuit. The path switching circuit is configured to select the first control line in CATV mode, the second control line in unpowered UHF mode, and the third control line in powered UHF mode, according to the setting of the mode setting switch, and connect the input terminal to the amplification circuit.

[0013] With this configuration, switching between operating modes and switching between supplying power via the input terminals can be achieved using a mode setting switch. In one aspect of the present disclosure, the signal processing circuit may further include a short-circuit circuit configured to short-circuit the input side of the UHF filter when the first control line is selected by the path switching circuit.

[0014] With this configuration, in operating modes where the UHF filter is not used, noise generated from the UHF filter can be suppressed, thereby improving signal quality. In one aspect of this disclosure, the signal processing circuit may further include a bias generation circuit configured to generate bias signals having different signal levels depending on whether a first control line is selected by a path switching circuit or whether a second or third control line is selected. The amplification circuit may include a level adjuster configured to change the attenuation of an intermediate signal according to the bias signal. The attenuation of the level adjuster may be set so that the level of the CATV signal input via the first control line and adjusted by the level adjuster is similar to the level of the UHF signal input via the second or third control line and adjusted by the level adjuster.

[0015] With this configuration, the output level from the booster does not vary significantly depending on the operating mode, and the signal level adjustment after switching modes can be easily done with only minor adjustments.

[0016] In one aspect of this disclosure, the amplifier circuit may further include an attenuation setting switch used to set the attenuation amount of the intermediate signal. The amplifier circuit may include a variable attenuator configured to attenuate the intermediate signal by an attenuation amount according to the setting of the attenuation setting switch. The attenuation amount of the variable attenuator may be set so that the level of the CATV signal after attenuation by the variable attenuator can be adjusted to the same extent, regardless of whether the CATV signal was obtained from a coaxial line termination device or an optical line termination device.

[0017] With this configuration, even if the source of the CATV signal changes between a coaxial cable and an optical fiber cable, the output level from the booster can be easily adjusted to be roughly the same before and after the change by operating the attenuation setting switch. [Brief explanation of the drawing]

[0018] [Figure 1] This is a plan view showing the arrangement of switches and other components on the top surface of the booster's casing. [Figure 2] This is a block diagram showing the overall configuration of the booster. [Figure 3] It is a block diagram showing the configuration of a first downlink circuit of a booster. [Figure 4] It is a block diagram showing the configuration of a signal processing circuit. MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [1. External Configuration] The booster 1 of the present embodiment is a booster for shared reception that is used by being attached to a switchboard or the like of a multiple dwelling house. As shown in FIG. 1 and FIG. 2, the booster 1 includes a box-shaped housing 10. In the housing 10 attached to the switchboard, a surface in contact with the switchboard is referred to as a bottom surface, a surface opposite to the bottom surface is referred to as a top surface, and four surfaces sandwiched between the bottom surface and the top surface are referred to as side surfaces.

[0020] The booster 1 includes, on the bottom surface of the housing 10, a flange 11 formed with a plurality of screw holes for fixing the housing 10 to a switchboard or the like. Further, the flange 11 may be provided with a functional ground terminal G used for grounding the housing 10.

[0021] The booster 1 includes, on one side surface of the housing 10, a power supply line L and four terminals T1 to T4. The power supply line L has a plug connected to a commercial power source at its distal end, and is used for receiving supply of 100 V AC.

[0022] The terminal T1 is used for input of UHF signals or input / output of CATV signals. A UHF signal is a signal of 470 MHz to 710 MHz allocated to terrestrial digital broadcasting. A CATV signal is composed of a downlink signal of 70 MHz to 962 MHz (hereinafter referred to as CATV downlink signal) and an uplink signal of 10 MHz to 60 MHz (hereinafter referred to as CATV uplink signal). The CATV downlink signal is input via the terminal T1, and the CATV uplink signal is output via the terminal T1.

[0023] Terminal T2 is used for inputting BS / CS signals or inputting / outputting mixed signals. BS / CS signals are signals in the 1030MHz to 3224MHz range allocated to BS and CS broadcasting. Mixed signals consist of a downstream signal (hereinafter referred to as the mixed downstream signal) which is a mixture of a UHF signal or CATV downstream signal and a BS / CS signal, and a CATV upstream signal. The mixed downstream signal is input via terminal T2, and the CATV upstream signal is output via terminal T2.

[0024] Terminal T3 is a measurement terminal used to monitor the output level of the signal output from terminal T4. Terminal T4 is used for outputting signals input via terminals T1 and T2, and for inputting CATV upstream signals. The signals output from terminal T4 include UHF signals or CATV signals, and may also include BS / CS signals. Terminal T4 is also used to supply DC power (e.g., DC15V) to booster 1 from an external source.

[0025] Booster 1 is equipped with multiple switches SW1, SW21, SW22, SW31, SW33, SW41, SW43 and multiple potentiometers VR23, VR32, VR42 on the top surface of the enclosure 10.

[0026] Switch SW1 is used to select whether the CATV downstream signal or UHF signal and the BS / CS signal are treated as "separate inputs" or as a "mixed input". When switch SW1 is set to "separate inputs", connect booster 1 so that the CATV downstream signal or UHF signal is input to terminal T1 and the BS / CS signal is input to terminal T2. When set to "mixed inputs", connect booster 1 so that terminal T1 is not used and the mixed downstream signal is input to terminal T2.

[0027] Switches SW21 and SW22, and volume VR23 are used to configure settings related to CATV downstream signals or UHF signals. Switch SW21 switches the reception mode to three levels: CATV mode, unpowered UHF mode, and powered UHF mode. However, in the display of switch SW21 in Figure 1, CATV mode is displayed as "CATV Downlink [V-ONU Connection]", powered UHF mode is displayed as "UHF (Power ON)", and unpowered UHF mode is simply displayed as "UHF". Hereafter, the unpowered UHF mode and powered UHF mode will be collectively referred to simply as UHF mode.

[0028] CATV mode is selected when using CATV signals, rather than UHF signals. CATV mode is also selected when the system is configured to bring in optical fiber cables via an optical network terminal (V-ONU).

[0029] The UHF mode is selected when using the UHF signal, out of the two available signals (UHF signal and CATV signal). However, the powered UHF mode is selected when a preamplifier or the like is connected in the transmission line connecting terminal T1 and the UHF antenna, requiring power supply via terminal T1 (e.g., DC 15V supply). The unpowered UHF mode is selected when power supply via terminal T1 is not required.

[0030] Switch SW22 sets the attenuation amount in an attenuator that adjusts the level of the UHF signal or CATV downstream signal input via terminal T1 or terminal T2. For example, it may be configured to allow three levels of adjustment: 10dB, 0dB, and 20dB.

[0031] Volume VR23 adjusts the gain of the amplifier that amplifies the UHF signal or CATV downstream signal, which is input via terminal T1 or terminal T2 and output from terminals T3 and T4. Switches SW31 and SW33, and volume VR32 are used to configure settings related to BS / CS signals.

[0032] Switch SW31 sets the amount of attenuation in the attenuator that adjusts the input level of the BS / CS signal input via terminal T2. For example, it may be configured to allow three levels of adjustment: 10dB, 0dB, and 20dB.

[0033] Volume VR32 adjusts the gain of the amplifier that amplifies the BS / CS signal, which is input via terminal T2 and output from terminals T3 and T4. Switch SW33 is set to ON if power supply via terminal T2 (e.g., DC15V supply) is required when a converter or similar device for the satellite antenna is connected in the transmission line connecting terminal T2 and the BS / CS antenna, and is set to OFF if power supply via terminal T2 is not required.

[0034] Switches SW41 and SW43, and volume control VR42 are used to configure the CATV upstream signal input via terminal T4. Switch SW43 sets the attenuation amount in the attenuator that adjusts the input level of the CATV upstream signal input from terminal T4. For example, it may be configured to allow two levels of adjustment: 0dB and 10dB.

[0035] Volume VR42 adjusts the gain of the amplifier that amplifies the CATV upstream signal, which is input from terminal T4 and output from terminal T1 or terminal T2. Switch SW41 switches the bandwidth of the CATV upstream signal input via terminal T4 in three stages: "Upstream Cut," "10-60MHz," and "30-60MHz." "Upstream Cut" is set when there is no CATV upstream signal input via terminal T4. "10-60MHz" is set when the full upstream signal bandwidth reserved for CATV upstream signals is used. "30-60MHz" is set when only the wider end of the upstream signal bandwidth is used, for example, when there is a lot of low-frequency noise below 30MHz.

[0036] [2. Functional Configuration] As shown in Figure 2, the booster 1 comprises power isolation filters 2 and 3, a first downlink circuit 4, a second downlink circuit 5, an uplink circuit 6, a converter power supply circuit 7, an input switching circuit 8, a power supply circuit 9, and first to fourth diplexers 21 to 24.

[0037] The converter power supply circuit 7 switches between supplying and cutting off power to the power isolation filter 2 of the power supply +B generated by the power supply circuit 9, according to the setting of switch SW33. The power isolation filter 2 outputs the downstream signal input from terminal T2 to the first diplexer 21, and outputs the upstream signal input from the first diplexer 21 to terminal T2, preventing the downstream and upstream signals from being output to the converter power supply circuit 7. In addition, the power isolation filter 2 outputs the power supply +B input via the converter power supply circuit 7 to terminal T2, preventing it from being output to the first diplexer 21.

[0038] The first diplexer 21 separates the input signal from the power supply separation filter 2 into a first downlink signal DN1, which includes the frequency bands of UHF signals and CATV downlink signals, and a second downlink signal DN2, which includes the frequency band of BS / CS signals. The first downlink signal DN1 is output to the input switching circuit 8, and the second downlink signal DN2 is output to the second downlink circuit 5. The first diplexer 21 outputs the input signal from the input switching circuit 8 (i.e., the CATV uplink signal) to the power supply separation filter 2, preventing it from being output to the second downlink circuit 5.

[0039] The input switching circuit 8 switches, according to the setting of switch SW1, between "separate input," where the UHF signal or CATV downstream signal is input from terminal T1 and the BS / CS signal is input from terminal T2, and "mixed input," where both signals are input from terminal T2. When switch SW1 is set to "separate input," the input switching circuit 8 conducts between terminal T1 and the second diplexer 22, outputs the input signal from terminal T1 (i.e., the UHF signal or CATV downstream signal) to the second diplexer 22, and outputs the input signal from the second diplexer 22 (i.e., the CATV upstream signal) to terminal T1. When switch SW1 is set to "mixed input", the input switching circuit 8 conducts the first diplexer 21 and the second diplexer 22, outputs the first downlink signal DN1 (i.e., UHF signal or CATV downlink signal) input from terminal T2 and supplied via the first diplexer 21 to the second diplexer 22, and outputs the input signal from the second diplexer 22 (i.e., CATV uplink signal) to terminal T2 via the first diplexer 21.

[0040] The second diplexer 22 outputs the input signal from the input switching circuit 8 (i.e., the UHF signal and the CATV downlink signal) to the first downlink circuit 4, preventing it from being output to the uplink circuit 6. The second diplexer 22 also outputs the input signal from the uplink circuit 6 (i.e., the CATV uplink signal) to the input switching circuit 8, preventing it from being output to the first downlink circuit 4.

[0041] The first downlink circuit 4 receives the input signal from the second diplexer 22 (i.e., the UHF signal or CATV downlink signal), adjusts its level according to the settings of switches SW21 and SW22, and volume VR23, and outputs it to the third diplexer 23. The first downlink circuit 4 also switches whether or not to supply power to an external device via terminal T1. Details of the first downlink circuit 4 will be described later.

[0042] The second downlink circuit 5 receives the second downlink signal DN2 (i.e., the BS / CS signal) from terminal T2 and is supplied via the first diplexer 21. The circuit adjusts the level according to the settings of switch SW31 and volume VR32 and outputs it to the fourth diplexer 24.

[0043] The upstream circuit 6 receives the input signal from the third diplexer 23 (i.e., the CATV upstream signal), adjusts its level according to the settings of switches SW41 and SW43, and volume VR42, and outputs it to the second diplexer 22.

[0044] The third diplexer 23 outputs the input signal from the first downlink circuit 4 (i.e., the UHF signal or the CATV downlink signal) to the fourth diplexer 24, preventing it from being output to the uplink circuit 6. The third diplexer 23 also outputs the input signal from the fourth diplexer 24 (i.e., the CATV uplink signal) to the uplink circuit 6, preventing it from being output to the first downlink circuit 4.

[0045] The fourth diplexer 24 outputs the input signal from the third diplexer 23 (i.e., the UHF signal or the CATV downstream signal) to the power isolation filter 3, preventing it from being output to the second downstream circuit 5. The fourth diplexer 24 also outputs the input signal from the second downstream circuit 5 (i.e., the BS / CS signal) to the power isolation filter 3, preventing it from being output to the third diplexer 23. In other words, the fourth diplexer 24 outputs a mixed signal DO, which is a mixture of the input signal from the third diplexer 23 and the input signal from the second downstream circuit 5, to the power isolation filter 3. Furthermore, the fourth diplexer 24 outputs the input signal from the power isolation filter 3 (i.e., the CATV upstream signal) to the third diplexer 23, preventing it from being output to the second downstream circuit 5. Terminal T3 is connected so that the mixed signal DO can be monitored.

[0046] The power isolation filter 3 outputs the input signal from the fourth diplexer 24 (i.e., the mixed signal DO) to terminal T4, and also outputs the upstream signal (i.e., the CATV upstream signal) input from terminal T4 to the fourth diplexer 24, preventing the downstream and upstream signals from being output to the power supply circuit 9. In addition, the power isolation filter 3 outputs the DC power supply (for example, DC 15V) input from terminal T4 to the power supply circuit 9, preventing it from being output to the fourth diplexer 24.

[0047] If the power supply circuit 9 is not receiving AC100V via the power line L, it outputs the DC power supplied via the power isolation filter 3 as the power supply +B used to power external devices via terminals T1 and T2. If the power supply circuit 9 is receiving AC100V via the power line L, it generates the power supply +B by performing an AC-DC conversion. The power supply circuit 9 also steps down the power supply +B to generate a DC12V control power supply +D, which it supplies to each circuit that makes up the booster 1.

[0048] In Booster 1, when switch SW1 is set to "separate input," a UHF signal or CATV downstream signal is input from terminal T1, and a BS / CS signal is input from terminal T2. The input signal from terminal T1 is level-adjusted in the first downstream circuit 4, and the input signal from terminal T2 is level-adjusted in the second downstream circuit 5. Both signals, after level-adjustment in the first downstream circuit 4 and the second downstream circuit 5, are mixed and output from terminal T4.

[0049] When switch SW1 is set to "mixed input," a mixed signal is input from terminal T2, and terminal T1 is left unused. The mixed signal from terminal T2 is separated into a UHF signal or CATV downstream signal and a BS / CS signal by the first diplexer 21. The UHF signal or CATV downstream signal is supplied to the first downstream circuit 4, and the BS / CS signal is supplied to the second downstream circuit 5. The following operation is the same as when switch SW1 is set to "separate input."

[0050] The DC power applied externally to terminal T4 is separated from other signals by the power isolation filter 3 and supplied to the power supply circuit 9, where it is converted into power supply +B and control power supply +D, which are then supplied to each part. The power supply +B is superimposed on terminal T1 via the first downstream circuit 4 and on terminal T2 via the converter power supply circuit 7.

[0051] The CATV upstream signal input from terminal T4 is separated from the DC power supply by the power supply isolation filter 3, and is then supplied to the upstream circuit 6 via the fourth diplexer 24 and the third diplexer 23. The upstream circuit 6 adjusts the level of the supplied CATV upstream signal and supplies it to the input switching circuit 8 via the second diplexer 22.

[0052] The input switching circuit 8 outputs the CATV upstream signal to terminal T1 when switch SW1 is set to "separate input", and outputs the CATV upstream signal to terminal T2 via the first diplexer 21 when switch SW1 is set to "mixed input".

[0053] [3. First Downward Circuit] The details of the first down-circuit 4 will be explained using Figures 3 and 4. As shown in Figure 3, the first downlink circuit 4 comprises a signal processing circuit 41, a variable attenuator 42, a first amplifier 43, a level adjuster 44, and a second amplifier 45.

[0054] The signal processing circuit 41 generates the intermediate signal DN and the bias signal BI according to the setting of switch SW21, and switches whether or not to supply power to the outside via terminal T1. Details will be described later.

[0055] The variable attenuator 42 includes a path switching circuit 421 and three attenuation lines AL1, AL2, and AL3. The path switching circuit 421 selects one of the three attenuation lines AL1, AL2, or AL3 according to the setting of switch SW22 and connects the output terminal of the signal processing circuit 41 to the input terminal of the first amplifier 43.

[0056] The path switching circuit 421 selects attenuation line AL1 when switch SW22 is set to "10dB", selects attenuation line AL2 when switch SW22 is set to "0dB", and selects attenuation line AL3 when switch SW22 is set to "20dB".

[0057] Attenuation line AL1 is configured to reduce the intensity of the intermediate signal DN passing through it by 10 dB. Attenuation line AL2 is configured to maintain the intensity of the intermediate signal DN passing through it as is. Attenuation line AL3 is configured to reduce the intensity of the intermediate signal DN passing through it by 20 dB. The attenuation amounts of attenuation lines AL1 to AL3 may be set to, for example, to compensate for the level difference that occurs when acquiring a CATV signal from a coaxial line versus from an optical line.

[0058] The first amplifier 43 amplifies the signal supplied from the variable attenuator 42 at a predetermined amplification factor. The level adjuster 44 is a semiconductor attenuator whose attenuation amount changes according to the signal level of the bias signal BI, and attenuates the signal amplified by the first amplifier 43. The level adjuster 44 is configured to attenuate the signal level by 7 dB when the bias signal BI indicates CATV mode, and to pass the signal through without attenuation when the bias signal BI indicates UHF mode. In other words, the attenuation amount of the level adjuster 44 is set so that the signal range that can be processed by the device connected downstream of the booster 1 is the same regardless of whether it is CATV mode or UHF mode. That is, the attenuation amount is set so that the level of the CATV signal after adjustment by the level adjuster 44 can be made to be approximately the same.

[0059] The second amplifier 45 amplifies the signal supplied from the level adjuster 44 at an amplification factor corresponding to the setting of the volume VR23 and supplies it to the next stage (i.e., the third diplexer 23). As shown in Figure 4, the signal processing circuit 41 includes a power supply voltage superposition circuit 410, a high-pass filter (hereinafter referred to as HPF) 411, a control voltage superposition circuit 412, a path switching circuit 413, a UHF filter 414, a short-circuit circuit 415, a bias generation circuit 416, and a UHF power supply circuit 417.

[0060] The power supply voltage superposition circuit 410 superimposes the power supply voltage +B, supplied via the UHF power supply circuit 417, onto the signal output from the first downlink circuit 4 to the second diplexer 22. The HPF411 removes the DC component (i.e., the power supply voltage +B superimposed via the power supply voltage superposition circuit 410) from the signal input to the first downlink circuit 4 and outputs it to the control voltage superposition circuit 412.

[0061] The control voltage superposition circuit 412 superimposes the control voltage +D used to drive the subsequent circuit onto the input signal from the HPF411. The path switching circuit 413 selects and connects one of the three control lines CL1, CL2, or CL3 between the output terminal of the control voltage superposition circuit 412 and the output terminal of the signal processing circuit 41, according to the setting of the switch SW21.

[0062] The route switching circuit 413 selects the first control line CL1 when the switch SW21 is set to "CATV mode", the second control line CL2 when the switch SW21 is set to "UHF mode without power supply", and the third control line CL3 when the switch SW21 is set to "UHF mode with power supply".

[0063] The first control line CL1 is configured to allow the input signal to pass through without modification. The second control line CL2 has a UHF filter 414 inserted that extracts signals included in the UHF signal frequency band from the input signal.

[0064] Furthermore, the second control line CL2 is equipped with a short circuit 415. The short circuit 415 is configured to short-circuit the upstream side of the UHF filter 414 when the first control line CL1 is selected by the path switching circuit 413, that is, when the system is set to CATV mode. This configuration is intended to suppress the unused UHF filter 414 from becoming a noise source when the system is set to CATV mode. Note that whether or not the first control line CL1 is selected may be determined, for example, by whether or not a control voltage +D is superimposed on the first control line CL1. The determination of whether or not the second control line CL2 and the third control line CL3 are selected can be done in the same manner.

[0065] The third control line CL3 is connected to the second control line CL2 and operates in the same way as when the second control line CL2 is selected. The bias generation circuit 416 generates a bias signal BI with different signal levels depending on whether the path switching circuit 413 has selected the first control line CL1 (i.e., the switch SW1 is set to "CATV mode") or the second control line CL2 or the third control line CL3 (i.e., the switch SW1 is set to "no-power UHF mode" or "powered UHF mode"). The bias signal BI is supplied to the level adjuster 44.

[0066] The UHF power supply circuit 417 is configured to supply the power supply voltage +B to the power supply voltage superposition circuit 410 only when the path switching circuit 413 has selected the third control line CL3 (i.e., when the switch SW1 is set to "Powered UHF mode").

[0067] In other words, in the first down-circuit 4, the power supply voltage +B is removed from the input signal, and then the control voltage +D is superimposed on the input signal. In the first downlink circuit 4 configured in this way, when the switch SW21 is set to "CATV mode", the input signal superimposed with the control voltage +D is supplied to the first control line CL1 and then directly to the variable attenuator 42. At this time, the bias generation circuit 416 outputs a bias signal BI having a signal level corresponding to CATV mode. At this time, the UHF filter 414 inserted into the second control line CL2 is kept in a state where its input side is short-circuited by the short-circuit circuit 415, i.e., in an inoperable state. In addition, the UHF power supply circuit 417 is kept in a stopped state where it does not supply the power supply voltage +B.

[0068] When switch SW21 is set to "no power supply UHF mode," the input signal superimposed with the control voltage +D is supplied to the second control line CL2. In this case, the short circuit 415 does not operate, and the UHF filter 414 operates, so the input signal is supplied to the subsequent variable attenuator 42 with signals other than those in the UHF band removed. In addition, the bias generation circuit 416 outputs a bias signal BI with a signal level corresponding to the UHF mode. Furthermore, the UHF power supply circuit 417 is kept in a stopped state without supplying the power supply voltage +B.

[0069] When switch SW21 is set to "Powered UHF Mode," the input signal superimposed with the control voltage +D is supplied to the third control line CL3. In this case, all components except the UHF power supply circuit 417 operate in the same way as when switch SW1 is set to "Powered-Off UHF Mode." The UHF power supply circuit 417 enters an operational state, supplying the power supply voltage +B, and power is supplied to the outside via terminal T1.

[0070] [4. Correspondence of Terms] In this embodiment, terminal T1 corresponds to the input terminal in this disclosure, and terminal T4 corresponds to the output terminal in this disclosure. Switch SW21 corresponds to the mode setting switch in this disclosure, and switch SW22 corresponds to the attenuation setting switch in this disclosure. Furthermore, the variable attenuator 42, the first amplifier 43, the level adjuster 44, and the second amplifier 45 correspond to the amplification circuit in this disclosure.

[0071] [5. Effects] As explained above, Booster 1 is configured so that a single switch SW21 allows the user to select whether to operate in "CATV mode" or "UHF mode," and whether or not to supply power to the preamplifier and other components inserted between it and the UHF antenna in "UHF mode."

[0072] Therefore, in a shared reception system using Booster 1, when switching from UHF mode to CATV mode, the power supply to the external device via terminal T1 can be reliably stopped. As a result, it is possible to suppress overheating of the external device, degradation of system functionality, and failure caused by unnecessary power supply to the external device, which consists of passive components such as attenuators inserted between terminal T1 and a surge protector to suppress the CATV signal level.

[0073] According to Booster 1, the two switches that were previously separate are integrated into a single switch SW21, which reduces the number of components and allows for a smaller product. Booster 1 generates bias signals BI with different signal levels depending on whether it is in "CATV mode" or "UHF mode." Using these bias signals BI, the level adjuster 44 automatically adjusts the output level so that it is approximately the same regardless of the mode. Therefore, the amount of adjustment required for the switch that adjusts the output level of Booster 1 does not vary significantly depending on the operating mode, and the signal level adjustment after mode switching can be easily completed with only minor adjustments. As a result, the amount of adjustment work is reduced, improving work efficiency.

[0074] In Booster 1, when operating in CATV mode, the input to the UHF filter 414 used in UHF mode is short-circuited, preventing the UHF filter 414 from operating. Therefore, when operating in CATV mode, noise generated from unused circuits such as the UHF filter 414 can be suppressed, improving signal quality.

[0075] [6. Other Embodiments] Although embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0076] In the above embodiment, the switch SW21 is configured to have the same settings whether the CATV signal is acquired from a coaxial line or an optical line, and the variable attenuator 42 operated by the switch SW22 is configured to adjust the level difference between the two. In contrast, for example, the switch SW21 could be configured to have four switching stages, so that even when using a CATV signal, the settings for acquiring it from a coaxial line or an optical line are different, and the system can be configured to automatically adjust so that the output level after attenuation is approximately the same regardless of which is selected.

[0077] [7. The technical concepts disclosed herein] [Item 1] An input terminal (T1) into which a UHF signal or CATV signal is input, A signal processing circuit (41) configured to process the input signal input from the aforementioned input terminal, Amplifier circuits (42-45) configured to at least amplify the intermediate signal output from the signal processing circuit, The output terminal (T4) outputs the signal processed by the aforementioned amplification circuit, A mode setting switch (SW21) is used to set the operating mode of the signal processing circuit to one of the following: CATV mode, unpowered UHF mode, or powered UHF mode. Equipped with, The signal processing circuit is configured such that, when the mode setting switch is set to the CATV mode, the input signal is used as the intermediate signal as is; when the mode setting switch is set to the unpowered UHF mode, the signal belonging to the frequency band of the UHF signal extracted from the input signal is used as the intermediate signal; and when the mode setting switch is set to the powered UHF mode, the signal belonging to the frequency band of the UHF signal extracted from the input signal is used as the intermediate signal, and power is supplied to an external device connected between the input terminal and the UHF antenna via the input terminal. booster.

[0078] [Item 2] The booster described in item 1, The aforementioned signal processing circuit is A UHF filter (414) configured to extract signals in the UHF frequency band, A UHF power supply circuit (417) configured to apply a power supply to the input terminal, A first control line (CL1) is configured to pass the input signal received by the signal processing circuit directly to the subsequent stage and output it there, A second control line (CL2) is configured to output the aforementioned input signal to a subsequent stage via the UHF filter, A third control line (CL3) is configured to output the aforementioned input signal to a subsequent stage via the UHF filter and to activate the UHF power supply circuit, A path switching circuit (413) is configured to connect the input terminal and the amplification circuit by selecting the first control line in the case of CATV mode, the second control line in the case of power-free UHF mode, and the third control line in the case of power-supplied UHF mode, according to the setting of the mode setting switch, Equipped with booster.

[0079] [Item 3] The booster described in item 2, The aforementioned signal processing circuit is The circuit further includes a short-circuit circuit (415) configured to short-circuit the input side of the UHF filter when the first control line is selected by the path switching circuit. booster.

[0080] [Item 4] A booster as described in item 2 or item 3, The aforementioned signal processing circuit is The circuit further includes a bias generation circuit (416) configured to generate bias signals having different signal levels depending on whether the first control line is selected by the path switching circuit or whether the second control line or the third control line is selected. The aforementioned amplification circuit is Includes a level adjuster (44) configured to change the attenuation amount of the intermediate signal according to the bias signal, The attenuation amount of the level adjuster is set so that the level of the CATV signal input via the first control line and adjusted by the level adjuster and the level of the UHF signal input via the second or third control line and adjusted by the level adjuster are adjusted to the same extent. booster.

[0081] [Item 5] A booster described in any one of items 1 through 4, The system further includes an attenuation setting switch (SW22) used to set the attenuation amount of the intermediate signal, The amplification circuit includes a variable attenuator (42) configured to attenuate the intermediate signal by an attenuation amount according to the setting of the attenuation amount setting switch. The attenuation amount of the variable attenuator is set so that the level of the CATV signal after attenuation by the variable attenuator can be adjusted to the same extent, regardless of whether the CATV signal was acquired from a coaxial line termination device or an optical line termination device. booster. [Explanation of Symbols]

[0082] 1…Booster, 2,3…Power supply isolation filter, 4…First downlink circuit, 5…Second downlink circuit, 6…Uplink circuit, 7…Converter power supply circuit, 8…Input switching circuit, 9…Power supply circuit, 10…Housing, 11…Flange, 21~24…First~Fourth diplexer, 41…Signal processing circuit, 42…Variable attenuator, 43…First amplifier, 44…Level adjuster, 45…Second amplifier, 410…Power supply voltage superimposition circuit, 411…HPF, 412…Control voltage Superimposed circuits, 413, 421…path switching circuits, 414…UHF filters, 415…short circuit, 416…bias generation circuit, 417…UHF power supply circuit, AL1~AL3…attenuation lines, CL1~CL3…control lines, G…terminal for functional ground, L…power line, SW1, SW21, SW22, SW31, SW33, SW41, SW43…switches, VR23, VR32, VR42…volumes, T1~T4…terminals.

Claims

1. An input terminal into which a UHF signal or CATV signal is input, A signal processing circuit configured to process the input signal received from the aforementioned input terminal, An amplification circuit configured to at least amplify the intermediate signal output from the signal processing circuit, An output terminal that outputs the signal processed by the aforementioned amplification circuit, A mode setting switch used to set the operating mode of the signal processing circuit to one of the following: CATV mode, unpowered UHF mode, or powered UHF mode. Equipped with, The signal processing circuit is configured such that, when the mode setting switch is set to the CATV mode, the input signal is used as the intermediate signal as is; when the mode setting switch is set to the unpowered UHF mode, the signal belonging to the frequency band of the UHF signal extracted from the input signal is used as the intermediate signal; and when the mode setting switch is set to the powered UHF mode, the signal belonging to the frequency band of the UHF signal extracted from the input signal is used as the intermediate signal, and power is supplied to an external device connected between the input terminal and the UHF antenna via the input terminal. The aforementioned signal processing circuit is A UHF filter configured to extract signals in the UHF frequency band, A UHF power supply circuit configured to apply a power supply to the aforementioned input terminal, A first control line is configured to pass the input signal received by the signal processing circuit directly to the subsequent stage and output it there. A second control line configured to output the aforementioned input signal to a subsequent stage via the UHF filter, A third control line is configured to output the aforementioned input signal to a subsequent stage via the UHF filter and to activate the UHF power supply circuit, A path switching circuit is configured to connect the input terminal and the amplification circuit by selecting the first control line in the case of CATV mode, the second control line in the case of the power-off UHF mode, and the third control line in the case of the power-supplied UHF mode, according to the setting of the mode setting switch. Equipped with booster.

2. The booster according to Claim 1, The aforementioned signal processing circuit is When the first control line is selected by the path switching circuit, the circuit further includes a short-circuit circuit configured to short-circuit the input side of the UHF filter. booster.

3. The booster according to Claim 1, The aforementioned signal processing circuit is The circuit further includes a bias generation circuit configured to generate bias signals having different signal levels depending on whether the first control line is selected by the path switching circuit or whether the second control line or the third control line is selected. The aforementioned amplification circuit is Includes a level adjuster configured to change the attenuation amount of the intermediate signal in accordance with the bias signal, The attenuation amount of the level adjuster is set so that the level of the CATV signal input via the first control line and adjusted by the level adjuster and the level of the UHF signal input via the second or third control line and adjusted by the level adjuster can be adjusted to the same extent. booster.

4. The booster according to Claim 1, The system further includes an attenuation setting switch used to set the attenuation amount of the intermediate signal, The amplification circuit includes a variable attenuator configured to attenuate the intermediate signal by an attenuation amount according to the setting of the attenuation amount setting switch. The attenuation amount of the variable attenuator is set so that the level of the CATV signal after attenuation by the variable attenuator can be adjusted to the same extent, regardless of whether the CATV signal was acquired from a coaxial line termination device or an optical line termination device. booster.

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