Channel processor

Abstract

To provide a technique of providing a channel processor capable of outputting a desired output waveform.SOLUTION: An LUT storage section 61 stores a correction value for each of switch settings SWi that designate waveform patterns from a waveform adjustment circuit 5 and for each of broadcast channels CHj included in a BS / CS-IF signals. The correction value is set based on a difference between a target level and a measured level. The correction value is used to correct an output of signal processing IC2 such that a signal level of a signal being output from an output terminal 12 matches the target level. The target level is logically calculated based on the switch setting SWi and the broadcast channel CHj. The measured level is measured at the output terminal 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to techniques for adjusting the level of a BS / CS-IF signal. [Background technology]

[0002] The following Patent Document 1 describes a technique for adjusting the signal level sent to a transmission line so as to compensate for the signal level difference when the signal level received at a terminal in a CATV system differs significantly between the low-frequency side and the high-frequency side due to the characteristics of the transmission line leading to the terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-219841 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a known channel processor that separates a television signal into signals for each broadcast channel and adjusts the signal level for each broadcast channel. The channel processor adjusts the signal level so that a certain output waveform is realized. The waveform here refers to the shape of a graph that shows the signal level of each broadcast channel on the frequency axis.

[0005] Since the loss characteristics of the transmission path from the channel processor to the terminal device vary, a configuration is considered in which a waveform adjustment circuit is provided after the signal processing IC, which enables the output waveform to be switched by setting a switch. The waveform adjustment circuit includes, for example, an attenuator, a tilt circuit, and an inverse tilt circuit, and switches the amount of attenuation in the attenuator and the waveform realized by the tilt circuit and inverse tilt circuit (i.e., the slope of the graph showing the frequency vs. signal level characteristics).

[0006] However, when using a waveform adjustment circuit, even if the signal processing IC is adjusted to obtain the desired characteristics, the intended output waveform is not necessarily obtained at the output of the channel processor. In other words, the waveform adjustment circuit has a different circuit configuration depending on the switch setting, and the characteristics vary for each circuit configuration, so it is difficult to realize the intended output waveform for all circuit configurations. In addition, the waveform adjustment circuit has the problem that the output waveform varies from product to product due to individual differences in the parts used.

[0007] One aspect of the present disclosure provides techniques for achieving an intended output waveform at the output of a channel processor. [Means for solving the problem]

[0008] One aspect of the present disclosure is a channel processor, comprising a level adjustment circuit, a waveform adjustment circuit, and a correction value storage unit. The level adjustment circuit is configured to adjust the signal level of a BS / CS-IF signal input from an input terminal for each broadcast channel so that the signal levels of the broadcast channels included in the BS / CS-IF signal are the same. The waveform adjustment circuit is configured to be able to select one of a plurality of waveform patterns representing the signal levels of each broadcast channel in the signal band of the BS / CS-IF signal. The waveform adjustment circuit is also configured to process a signal output from the level adjustment circuit and output the processed signal from an output terminal so that a selection pattern, which is the selected waveform pattern, is realized. The correction value storage unit is configured to store a correction value for correcting the output of the level adjustment circuit so that the signal level of the signal output from the output terminal matches a target level. The correction value is set based on the difference between a target level and a measurement level detected for each waveform pattern and each broadcast channel. The target level is a signal level at the output terminal that is theoretically calculated based on the selection pattern and the selected broadcast channel. The measurement level is a signal level measured at the output terminal. The level adjustment circuit corrects the signal level for each broadcast channel in accordance with the correction value stored in the correction value storage unit.

[0009] With this configuration, the intended waveform pattern can be obtained from the output terminal regardless of which waveform pattern is selected. As a result, when installing the channel processor, it is possible to reduce the effort required to adjust the signal levels of all broadcast channels so that they are approximately the same for the BS / CS-IF signals input to the terminal device.

[0010] In one aspect of the present disclosure, the waveform pattern may include at least one of a pattern set so that the signal level increases as the frequency increases, and a pattern set so that the signal level decreases as the frequency decreases.

[0011] In one aspect of the present disclosure, the waveform adjustment circuit may include at least one of an attenuator, a tilt circuit, and an inverse tilt circuit. The attenuator has a characteristic of attenuating a signal in a signal band by a constant attenuation amount. The tilt circuit has a characteristic of attenuating a signal in a signal band by a larger attenuation amount as the frequency is lower. The inverse tilt circuit has a characteristic of attenuating a signal in a signal band by a larger attenuation amount as the frequency is higher.

[0012] In one aspect of the present disclosure, at least one of the attenuator, the tilt circuit, and the inverse tilt circuit may be configured to be able to switch the amount of attenuation in multiple stages. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a block diagram showing the configuration of a channel processor and a measurement system. [Diagram 2] FIG. 2 is an explanatory diagram showing the operation of the signal processing IC. [Diagram 3] 11 is a table showing the correspondence between switch settings and characteristics of a waveform adjustment circuit. [Figure 4] 1 is an explanatory diagram illustrating typical characteristics of a waveform adjustment circuit; [Diagram 5] FIG. 11 is an explanatory diagram illustrating an example of the contents of a lookup table. [Figure 6] 13 is a flowchart of an LUT generation process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [1. Configuration] 1 receives a BS / CS-IF signal from a BS / CS antenna 71 or the like via an input terminal 11, adjusts the signal level of each broadcast channel contained in the BS / CS-IF signal, and outputs it from an output terminal 12. A terminal device 72 such as a television that uses the BS / CS-IF signal is connected to the output terminal 12.

[0015] BS / CS-IF signals are signals with frequencies ranging from 1032 MHz to 3224 MHz. BS / CS-IF signals are made up of 50 channels in total, including 12 channels of BS right-handed and BS left-handed signals, and 13 channels of CS right-handed and CS left-handed signals.

[0016] The channel processor 1 includes a signal processing IC 2, a filter 3, an amplifier circuit 4, a waveform adjustment circuit 5, and a control circuit 6. The signal processing IC2 adjusts the level of the BS / CS-IF signal input from the input terminal 11 so that the signal level of each broadcast channel becomes a predetermined level. The predetermined level may be, for example, the same level for all broadcast channels, or it may be different for each broadcast channel. When adjusting the level, the signal processing IC2 uses a look-up table (hereinafter, LUT) to perform level correction for each broadcast channel. The signal processing IC2 converts the level-adjusted baseband signal back to the original frequency, synthesizes the frequency-converted signals of all broadcast channels, converts it into an analog signal, and outputs it.

[0017] That is, as shown in Fig. 2, the signal processing IC2 adjusts the waveform of the input signal, which has a different signal level for each broadcast channel, so that all broadcast channels have the same level (83 dBμV in Fig. 2), and then adds the correction value indicated in the LUT and outputs it. The correction value is set in the range of 0 to 20 dB, with 10 dB as the initial value, according to the LUT generated by the LUT generation process described later.

[0018] 1, the filter 3 extracts signals in a signal band or removes signals outside the signal band from the signal output from the signal processing IC 2. As the filter 3, for example, a high-pass filter is used.

[0019] The amplifier circuit 4 amplifies the output of the filter 3 to a level required according to the environment in which the channel processor 1 is installed (for example, the characteristics and length of the transmission line from the output terminal 12 to the terminal device 72, etc.).

[0020] Returning to Fig. 1, waveform adjustment circuit 5 adjusts the signal output from amplifier circuit 4 to a desired waveform pattern in accordance with the operational states of switches 13 to 15, and outputs it from output terminal 12. The waveform pattern refers to the shape pattern of a graph that indicates the signal level at each frequency in the signal domain.

[0021] The signal input to the waveform adjustment circuit 5, that is, the signal output from the signal processing IC 2, has a basic frequency characteristic (hereinafter, basic characteristic). The basic characteristic is one of the waveform patterns.

[0022] Waveform adjustment circuit 5 includes an attenuator (hereinafter, ATT) 51, a tilt circuit 52, and an inverse tilt circuit 53. ATT 51, tilt circuit 52, and inverse tilt circuit 53 may be connected in series. Waveform adjustment circuit 5 realizes a plurality of waveform patterns obtained by processing basic characteristics by switching the characteristics of ATT 51, tilt circuit 52, and inverse tilt circuit 53 in response to the operation of switches 13 to 15. The operation states of switches 13 to 15 are input to control circuit 6 as mode setting information MOD that specifies a waveform pattern, and are also output to the outside via output terminal 17. The mode setting information MOD is represented by switch settings SW00 to SW11 that respectively correspond to different operation states of switches 13 to 15.

[0023] The ATT 51 has a characteristic of uniformly attenuating the entire signal band of the BS / CS-IF signal (i.e., 1032 MHz to 3224 MHz). The ATT 51 realizes two levels of attenuation, for example, "0 dB" and "10 dB", according to the setting of the switch 13.

[0024] The tilt circuit 52 has a characteristic that the lower the frequency in the signal band, the greater the attenuation, and the attenuation changes linearly with frequency. The tilt circuit 52 realizes three types of characteristics with different amounts of change in attenuation according to the setting of the switch 14. The settings of the switch 14 are expressed as "0 dB", "6 dB", and "12 dB", for example. In all three types of characteristics realized by the tilt circuit 52, the attenuation at the maximum frequency in the signal band is 0 dB, and the attenuation at the minimum frequency is 0 dB, 6 dB, or 12 dB according to the setting of the switch 14.

[0025] Inverse tilt circuit 53 has a characteristic that the attenuation increases as the frequency in the signal band increases, and the attenuation changes linearly with frequency. Inverse tilt circuit 53 realizes two types of characteristics with different amounts of change in attenuation according to the setting of switch 15. The settings of switch 15 are expressed as "0 dB" and "10 dB", for example. In both of the two types of characteristics realized by inverse tilt circuit 53, the attenuation at the minimum frequency in the signal band is 0 dB, and the attenuation at the maximum frequency is 0 dB or 10 dB according to the setting of switch 15.

[0026] 3, waveform adjustment circuit 5 can realize 12 patterns of characteristics (i.e., waveform patterns) identified by switch settings SW00 to SW11 by operating switches 13 to 15. In other words, waveform adjustment circuit 5 realizes a desired waveform pattern by processing the signal output by signal processing IC 2 using ATT 51, tilt circuit 52, and inverse tilt circuit 53.

[0027] As a representative example, the output of waveform adjustment circuit 5 is shown in FIG. 4 for each of switch settings SW00, SW01, and SW04. The characteristics of waveform adjustment circuit 5 in the case of switch setting SW00 (hereinafter, basic characteristics) will be described. In this case, all of switches 13 to 15 are set to "0 dB." The output of waveform adjustment circuit 5 has a signal level of 93 dBμV at the minimum frequency of the signal band, a signal level of 103 dBμV at the maximum frequency, and a characteristic (hereinafter, basic characteristics) in which the signal level increases linearly as the frequency increases. The basic characteristics are set so that the signal level of the BS / CS-IF signal input to terminal device 72 via the transmission line is the same for all broadcast channels, assuming that the transmission line from channel processor 1 to terminal device 72 is of a reference length. In other words, the basic characteristics are set taking into consideration that the amount of attenuation increases in the transmission line as the frequency increases.

[0028] The characteristics of the waveform adjustment circuit 5 in the case of switch setting SW01 will be described. In this case, both the ATT 51 and the tilt circuit 52 are set to "0 dB", and the inverse tilt circuit 53 is set to "10 dB". The output of the waveform adjustment circuit 5 has a characteristic in which the signal level of the maximum frequency of the signal band is reduced by 10 dB from the basic characteristic described above. Specifically, the signal level at the minimum frequency of the signal band is 93 dBμV, and the signal level at the maximum frequency is also 93 dBμV, that is, the signal level of all channels is the same. This characteristic is used, for example, when the transmission line is significantly shorter than the reference length and the loss difference due to the difference in frequency in the transmission line is smaller than the loss difference assumed in the basic characteristic.

[0029] The characteristics of the waveform adjustment circuit 5 in the case of the switch setting SW04 will be described. In this case, both the ATT 51 and the inverse tilt circuit 53 are set to "0 dB", and the tilt circuit 52 is set to "12 dB". The output of the waveform adjustment circuit 5 has a characteristic in which the signal level at the minimum frequency of the signal band is reduced by 12 dB from the basic characteristic described above. Specifically, the signal level at the minimum frequency of the signal band is 81 dBμV, and the signal level at the maximum frequency is 103 dBμV, that is, the rate at which the signal level increases with frequency (i.e., the slope of the waveform) is greater than the basic characteristic. This characteristic is used, for example, when the transmission line is significantly longer than the reference length and the loss difference due to the difference in frequency in the transmission line is greater than the loss difference assumed in the basic characteristic.

[0030] Detailed explanations of switch settings other than SW00, SW01, and SW04 will be omitted. By appropriately changing the settings of switches 14 and 15, six types of frequency characteristics with different rates of increase and decrease in signal level with respect to frequency (i.e., characteristic slopes) can be realized. By changing the setting of switch 13, it is possible to reduce the signal level of the signal output from waveform adjustment circuit 5 by 10 dB across the entire signal band.

[0031] The operational states of the switches 13 to 15 are also input to the control circuit 6. The control circuit 6 includes an LUT storage unit 61. The control circuit 6 controls the operation of the signal processing IC 2 in accordance with the operational states of the switches 13 to 15 input from the waveform adjustment circuit 5 and the LUT stored in the LUT storage unit 61.

[0032] As shown in Fig. 5, the LUT stores correction values ​​used for signal level correction performed by the signal processing IC2 in association with combinations of switch settings SW00-SW11 and broadcast channels CH00-CH49. That is, the LUT stores 600 correction values, which are combinations of the number of switch settings SW00-SW11 (i.e., 12) and the number of broadcast channels included in the BS / CS-IF signal (i.e., 50). Fig. 5 shows multiple correction values ​​(i.e., "initial setting", "product number 1", "product number 2", ...) for each setting specified by the combination of switch settings and broadcast channels. This is to visually show that the correction values ​​differ for each product and how the initial values ​​are set, and the actual LUT shows one correction value for each of the 600 settings.

[0033] The correction value is used to suppress the variation in signal level occurring among the respective broadcast channels in the signal output from output terminal 12. That is, even if the signal level is adjusted by signal processing IC 2 so as to have the desired characteristics (i.e., basic characteristics), the signal level of the signal that passes through waveform adjustment circuit 5, amplifier circuit 4, and filter 3 and is output from output terminal 12 will vary among the respective broadcast channels. Furthermore, due to individual differences in the components that make up waveform adjustment circuit 5, amplifier circuit 4, and filter 3, the way in which the signal level varies will differ for each product of channel processor 1. This variation will be suppressed.

[0034] Control circuit 6 is configured to be able to rewrite the LUT stored in LUT storage unit 61 in accordance with an instruction from an external device connected to GPI terminal 16. Control circuit 6 is also configured to be able to provide the operational states of switches 13 to 15 input from waveform adjustment circuit 5 in accordance with an instruction from an external device connected to GPI terminal 17. GPI is an abbreviation for General Purpose Interface and is a general-purpose input / output terminal.

[0035] The control circuit 6 may be realized by a computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Also, the method of realizing the functions included in the control circuit 6 does not necessarily have to include software, and some or all of the functions may be realized by hardware.

[0036] [2. Measurement system] The measurement system 80 used to generate the LUT will now be described. As shown in FIG. 1, the measurement system 80 includes a signal generator 81, a signal level measuring device 82, an LUT generating device 83, and a data writing device 84.

[0037] The signal generator 81 is used by connecting it to the input terminal 11 of the channel processor 1. The signal generator 81 supplies to the input terminal 11 a reference signal having a constant level over the entire signal band.

[0038] The signal level measuring device 82 is used by being connected to the output terminal 12 of the channel processor 1. The signal level measuring device 82 is a spectrum analyzer or the like, and measures the signal level of the BS / CS-IF signal output from the output terminal 12 for each broadcast channel.

[0039] The LUT generator 83 calculates correction values ​​that are components of the LUT for each switch setting and each broadcast channel according to the measurement results from the signal level measuring device 82 and the switch settings obtained from the channel processor 1 via the GPI terminal 17.

[0040] The data writing device 84 writes the LUT generated by the LUT generating device 83 into the LUT storage unit 61 via the GPI terminal 16 of the channel processor 1 . Both the LUT generating device 83 and the data writing device 84 may be realized by a computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Also, the method of realizing the functions included in the LUT generating device 83 and the data writing device 84 does not necessarily need to include software, and some or all of the functions may be realized by hardware.

[0041] [3. LUT generation process] Next, the LUT generation procedure executed by the LUT generation device 83 using the measurement system 80 will be described with reference to the flowchart shown in FIG.

[0042] In S110, the LUT generating device 83 initializes all of the LUT values ​​Lc(i,j) to 10 dB. i is an identifier for identifying the switch setting SWi, and is any one of 00 to 11. j is an identifier for identifying the broadcast channel CHj, and is any one of 00 to 49.

[0043] In S 120 , the LUT generating device 83 activates the signal generator 81 to start supplying a reference signal to the input terminal 11 . In S130, the LUT generating device 83 acquires the switch settings from the channel processor 1 via the GPI terminal 17. At this time, a notification may be sent to the user of the measurement system 80 to prompt them to operate the switches 13 to 15. Each time the user receives a notification, he or she operates the switches 13 to 15 so that the switch settings SW00 to SW11 are specified in order. In the following, the switch setting corresponding to the switch setting acquired in S130 is referred to as SWi.

[0044] In S140, the LUT generating device 83 selects a broadcast channel. Specifically, in the switch setting acquired in S130, broadcast channels for which the processes of S150 to S170 described below have not been performed are sequentially selected. In the following, the broadcast channel selected in S140 is referred to as CHj.

[0045] In S150, the LUT generating device 83 obtains from the signal level measuring device 82 the measurement level Lo of the broadcast channel selected in S140, that is, the signal level at the output terminal 12.

[0046] In S160, the LUT generating device 83 calculates and stores the correction value Lc(i,j) according to equation (1). Lc(i,j)←Lc(i,j)+(Lf-Lo) (1) Lf is a signal level (hereinafter, target level) that is expected to be output from output terminal 12 when a reference signal is input from input terminal 11. The target level Lf is theoretically calculated based on the basic characteristics, the switch setting SWi acquired in S130, and the broadcast channel CHj selected in S140.

[0047] That is, when the measurement level Lo is smaller than the target level Lf, the correction value Lc(i,j) is larger than the initial value, and when the measurement level Lo is larger than the target level Lf, the correction value Lc(i,j) is smaller than the initial value. In other words, the correction value is set so that the measurement level Lo becomes a value that matches the target level Lf.

[0048] In S170, the LUT generating device 83 reacquires from the signal level measuring device 82 the measurement level Lo of the broadcast channel selected in S140. In S180, the LUT generating device 83 judges whether the difference Lf-Lo between the target level Lf and the reacquired measurement level Lo is within the allowable range. The allowable range is, for example, -2 dB≦Lf-Lo≦1 dB. If the LUT generating device 83 judges that the difference Lf-Lo is within the allowable range, the process proceeds to S190. If the LUT generating device 83 judges that the difference Lf-Lo is outside the allowable range, the process proceeds to S150, whereby the correction value Lc is reset.

[0049] In S190, the LUT generating device 83 determines whether or not all broadcast channels CH00 to CH49 have been selected. If all broadcast channels have been selected, the process proceeds to S200, and if there are any unselected broadcast channels, the process returns to S140, and the processes of S140 to S180 are repeated for the unselected broadcast channels.

[0050] In S200, the LUT generating device 83 determines whether or not all switch settings SW00 to SW11 have been selected. If all switch settings have been selected, the process proceeds to S210, and if there are unselected switch settings, the process returns to S130, and the processes of S130 to S190 are repeated for the unselected switch settings.

[0051] In S210, the LUT generating device 83 stops the signal generator 81, thereby stopping the supply of the reference signal to the input terminal 11, and ends the process. The data writing device 84 acquires the LUT generated by the LUT generating device 83 and writes it into the LUT storage unit 61 .

[0052] [4. Correspondence of terminology] The signal processing IC2 of this embodiment corresponds to the level adjustment circuit in this disclosure, and the LUT storage unit 61 corresponds to the correction value storage unit in this disclosure. The waveform pattern realized by the waveform adjustment circuit 5 by the switch setting SWi acquired in S130 of this embodiment corresponds to the selection pattern in this disclosure.

[0053] [5. Effects] According to the embodiment described above in detail, the following effects are achieved. In the channel processor 1, the output of the signal processing IC2, which has flat characteristics, is corrected using an LUT. The LUT has correction values ​​set for each switch setting SW00-SW11 and each broadcast channel CH00-CH49. The correction values ​​are set so that variations occurring in the downstream of the signal processing IC2 are offset and the signal output from the output terminal 12 becomes a target level determined by the switch setting SWi and the broadcast channel CHj.

[0054] Therefore, according to the channel processor 1, no matter which switch setting SW00-SW11 is selected, the characteristics of the signal output from the output terminal 12 have the intended waveform pattern. As a result, when installing the channel processor 1, it is possible to reduce the effort required to adjust the BS / CS-IF signals input to the terminal device 72 so that the signal levels of all broadcast channels are approximately the same.

[0055] 6. Other embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0056] (a) In the above embodiment, the number of switch settings, that is, the number of waveform patterns that can be realized by waveform adjustment circuit 5, is set to 12. However, the number of switch settings may be less than twelve or more than twelve.

[0057] (b) In the above embodiment, waveform adjustment circuit 5 is configured using ATT 51, tilt circuit 52, and inverse tilt circuit 52, but it may be configured using any one or any two of these.

[0058] (c) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0059] (d) In addition to the above-described channel processor 1, the present disclosure can also be realized in various forms, such as a system including the channel processor 1 as a component, a correction method for a BS / CS-IF signal, and the like.

[0060] [7. Technical Concepts Disclosed in This Specification] [Item 1] a level adjustment circuit configured to adjust a signal level of a BS / CS-IF signal input from an input terminal for each broadcast channel included in the BS / CS-IF signal so that the signal level of the broadcast channel included in the BS / CS-IF signal becomes a predetermined level; a waveform adjustment circuit configured to be able to select one of a plurality of waveform patterns representing the signal level for each of the broadcasting channels in the signal band of the BS / CS-IF signal, and configured to process the signal output from the level adjustment circuit and output the processed signal from an output terminal so as to realize a selected waveform pattern that is the selected waveform pattern; a correction value storage unit configured to store a correction value for correcting an output of the level adjustment circuit so that a signal level of a signal output from the output terminal coincides with a target level; Equipped with the correction value is set based on a difference between the target level and a measured level detected for each of the waveform patterns and for each of the broadcast channels; the target level is a signal level at the output terminal theoretically calculated based on the selection pattern and the frequency of the broadcast channel; the measurement level is a signal level measured at the output terminal; the level adjustment circuit corrects the signal level for each of the broadcast channels in accordance with the correction value stored in the correction value storage unit. Channel processor.

[0061] [Item 2] Item 1, a channel processor comprising: The waveform pattern includes at least one of a pattern in which the signal level is set to be higher as the frequency is higher and a pattern in which the signal level is set to be lower as the frequency is lower. Channel processor.

[0062] [Item 3] A channel processor according to item 1 or 2, The waveform adjustment circuit includes at least one of an attenuator having a characteristic of attenuating a signal in the signal band by a constant attenuation amount, a tilt circuit having a characteristic of attenuating a signal in the signal band by a larger attenuation amount as the frequency of the signal is lower, and an inverse tilt circuit (33) having a characteristic of attenuating a signal in the signal band by a larger attenuation amount as the frequency of the signal is higher. Channel processor.

[0063] [Item 4] Item 3. A channel processor according to claim 3, At least one of the attenuator, the tilt circuit, and the reverse tilt circuit is configured to be able to switch the amount of attenuation in a plurality of stages. Channel processor. [Explanation of symbols]

[0064] 1...channel processor, 2...signal processing IC, 3...filter, 4...amplification circuit, 5...waveform adjustment circuit, 6...control circuit, 11...input terminal, 12...output terminal, 13-15...switch, 16, 17...GPI terminal, 51...attenuator (ATT), 52...tilt circuit, 53...reverse tilt circuit, 71...antenna, 72...terminal device, 80...measurement system, 81...signal generator, 82...signal level meter, 83...LUT generation device, 84...data writing device, 61...LUT memory unit.

Claims

1. a level adjustment circuit configured to adjust a signal level of a BS / CS-IF signal input from an input terminal for each broadcast channel so that the signal level of the broadcast channel included in the BS / CS-IF signal becomes a predetermined level; a waveform adjustment circuit configured to be able to select one of a plurality of waveform patterns representing the signal level for each of the broadcasting channels in the signal band of the BS / CS-IF signal, and configured to process the signal output from the level adjustment circuit and output the processed signal from an output terminal so as to realize a selected waveform pattern that is the selected waveform pattern; a correction value storage unit configured to store a correction value for correcting an output of the level adjustment circuit so that a signal level of a signal output from the output terminal coincides with a target level; Equipped with the correction value is set based on a difference between the target level and a measured level detected for each of the waveform patterns and for each of the broadcast channels; the target level is a signal level at the output terminal theoretically calculated based on the selection pattern and the frequency of the broadcast channel; the measurement level is a signal level measured at the output terminal; the level adjustment circuit corrects the signal level for each of the broadcast channels in accordance with the correction value stored in the correction value storage unit. Channel processor.

2. 2. A channel processor according to claim 1, comprising: The waveform pattern includes at least one of a pattern in which the signal level is set to be higher as the frequency is higher and a pattern in which the signal level is set to be lower as the frequency is lower. Channel processor.

3. 2. A channel processor according to claim 1, comprising: The waveform adjustment circuit includes at least one of an attenuator having a characteristic of attenuating a signal in the signal band by a constant attenuation amount, a tilt circuit having a characteristic of attenuating a signal in the signal band by a larger attenuation amount as the frequency of the signal is lower, and an inverse tilt circuit having a characteristic of attenuating a signal in the signal band by a larger attenuation amount as the frequency of the signal is higher. Channel processor.

4. 4. A channel processor according to claim 3, comprising: At least one of the attenuator, the tilt circuit, and the reverse tilt circuit is configured to be able to switch the amount of attenuation in a plurality of stages. Channel processor.

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