Patent ID: 12224785

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, modes for carrying out the present technology will be described. The description will be made in the following order.<0. Overview><1. First Embodiment><2. Second Embodiment><3. Third Embodiment>

0. Overview

Configuration Example of Conventional Broadcast Receiving System

FIG.1is a block diagram illustrating a configuration example of a conventional broadcast receiving system.

A broadcast receiving system1inFIG.1is a broadcast receiving system that receives broadcast signals of terrestrial digital broadcasting and cable digital broadcasting and a broadcast signal of satellite digital broadcasting.

The broadcast receiving system1includes a terrestrial broadcasting antenna11, a satellite digital broadcasting antenna12, a reception device13, and a display14.

The terrestrial broadcasting antenna11receives a terrestrial digital broadcast wave transmitted from a transmission device of a broadcast station (not illustrated), and outputs a radio frequency (RF) signal to the reception device13. The broadcast wave of terrestrial broadcasting is modulated and transmitted by the transmission device. A cable digital broadcast wave is transmitted by a cable, and the cable is connected to the reception device13instead of the terrestrial broadcasting antenna11.

Note that the frequency band of an RF signal of the terrestrial digital broadcasting and the frequency band of an RF signal of the cable digital broadcasting are close frequency bands, and substantially the same processing is performed on the RF signal of the terrestrial digital broadcasting and the RF signal of the cable digital broadcasting. Therefore, hereinafter, the terrestrial digital broadcasting and the cable digital broadcasting will be collectively referred to as terrestrial broadcasting in a case where it is not particularly necessary to distinguish the terrestrial digital broadcasting and the cable digital broadcasting.

The satellite digital broadcasting antenna12receives a satellite digital broadcasting wave transmitted from a satellite transmission device (not illustrated). The satellite digital broadcasting antenna12includes a frequency converter (not illustrated). The satellite digital broadcasting antenna12performs frequency conversion on an RF signal using the frequency converter, and outputs a first IF signal, which is a signal after the frequency conversion, to the reception device13.

The reception device13includes a tuner21, a demodulation unit22, a processing unit23, and a control unit24.

The tuner21includes one chip (semiconductor chip) such as an IC. The tuner21selects the frequency of a channel desired by a user under the control of the control unit24. The tuner21amplifies an RF signal of the selected frequency and converts the frequency of the RF signal into a low frequency.

At this time, the RF signal of the terrestrial broadcasting is converted into an IF signal, which is a signal of an IF frequency of about 4 MHz, by a detection method called a “superheterodyne method”.

The first IF signal of the satellite digital broadcasting is converted into baseband (BB) signals of 0 MHz to several 10 MHz by a detection method called a “direct conversion method”. The BB signals include an I signal (0 degrees) and a Q signal (90 degrees) whose phases are orthogonal to each other. Hereinafter, the BB signals will also be referred to as IQ signals. In addition, the I signal of the BB signals will be referred to as a BB(I) signal, and the Q signal of the BB signals will be referred to as a BB(Q) signal.

The tuner21includes an output terminal that outputs the IF signal, an output terminal that outputs the BB(I) signal, and an output terminal that outputs the BB(Q) signal, and outputs the signal from each of the output terminals to a corresponding analog digital converter (ADC) of the demodulation unit22.

The demodulation unit22performs demodulation processing under the control of the control unit24. The demodulation unit22includes ADCs41-1to41-3, demodulation processing units42-1and42-2, and error correction units43-1and43-2.

The ADCs41-1to41-3respectively convert the IF signal, the BB(I) signal, and the BB(Q) signal, which are analog signals supplied from the tuner21, into digital signals.

The ADC41-1converts the IF signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit42-1. The ADC41-2converts the BB(I) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit42-2. The ADC41-3converts the BB(Q) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit42-2.

The demodulation processing units42-1and42-2perform the demodulation processing on the converted digital signals, and output the demodulated signals to the error correction units43-1and43-2, respectively.

The error correction units43-1and43-2perform error correction on the demodulated signals and output, for example, transport stream (TS) signals obtained as a result of the error correction to the processing unit23.

Under the control of the control unit24, the processing unit23performs demux processing, demultiplexing processing, and decoding processing on data of the TS signals supplied from the error correction units43-1and43-2.

The demux processing is, for example, processing of separating video content into a video portion, an audio portion, a subtitle portion, and the like. The demultiplexing processing is processing of separating, for example, video data and audio data included in the data. The decoding processing is processing of generating a video signal by decoding the video data, and the generated video signal is output to the display14. Furthermore, the decoding processing is processing of generating an audio signal by decoding the audio data, and the generated audio signal is output to a speaker (not illustrated).

The control unit24includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like. The control unit24executes a program stored in the ROM or the like, and controls the tuner21, the demodulation unit22, and the processing unit23according to a user instruction signal from an operation input unit (not illustrated).

The display14displays a video image representing the video signal supplied from the processing unit23.

Configuration Example of Conventional Tuner

FIG.2is a diagram illustrating a configuration example of the tuner inFIG.1.

The tuner21inFIG.2includes an RF input terminal101, a first IF input terminal102, RF voltage gain amplifiers (VGAs (RFVGAs))103and104, RF filters105-1to105-n, an RF filter106, and a mixer (MIX)107. Furthermore, the tuner21includes a complex filter/low pass filter (LPF)108, a switch109, an IQ combiner110, a switch111, an IF VGA (IFVGA)112, BB VGAs (BBVGAs)113and114, an output terminal115, an output terminal116, and an output terminal117.

The RF input terminal101receives the RF signal, which is a terrestrial broadcast signal supplied from the terrestrial broadcasting antenna11, and outputs the RF signal to the RFVGA103.

The first IF input terminal102receives the first intermediate frequency (IF) signal supplied from the satellite digital broadcasting antenna12, which is a signal obtained by frequency conversion on the RF signal as a satellite digital broadcast signal, and outputs the first IF signal to the RFVGA104.

The RFVGAs103and104are VGAs whose amplification degree can be varied by a control voltage that changes according to the magnitude of the signal level of the RF signal. The RFVGA103amplifies the RF signal supplied from the RF input terminal101. The RF signal is supplied to an RF filter of a frequency band corresponding to the frequency of a selected channel among the RF filters105-1to105-n.

The RFVGA104amplifies the first IF signal supplied from the first IF input terminal102. The first IF signal is supplied to the RF filter106.

The RF filters105-1to105-ninclude a plurality of RF filters corresponding to frequencies of channels of the terrestrial broadcasting. Each of the RF filters105-1to105-ncorresponding to the frequency of a channel performs filtering by tuning the frequency of the RF signal supplied from the RFVGA103to the frequency of the channel. The RF signal filtered by one of the RF filters105-1to105-nis output to the MIX107.

Note that, hereinafter, the RF filters105-1to105-nwill be referred to as an RF filter105in a case where it is not particularly necessary to distinguish the RF filters105-1to105-n.

The RF filter106includes an RF filter corresponding to the frequency of the satellite digital broadcasting. The RF filter106performs filtering by tuning the frequency of the first IF signal supplied from the RFVGA104to the frequency of the RF filter106. The first IF signal filtered by the RF filter106is output to the MIX107.

The MIX107is a frequency conversion circuit (mixer) that converts a high frequency of the RF into a low frequency of the IF or baseband (BB). When the filtered RF signal or first IF signal is supplied to the MIX107, an oscillation signal I1of the I signal (0 degrees) and an oscillation signal Q1of the Q signal (90 degrees) whose phases are orthogonal to each other are also supplied to the MIX107.

The RF signal is frequency-converted into an IF(I) signal and an IF(Q) signal by the oscillation signal I1and the oscillation signal Q1supplied to the MIX107and supplied to the complex filter/LPF108. At this time, an image component may be added to the IF(I) signal and the IF(Q) signal.

The first IF signal is frequency-converted into the BB(I) signal and the BB(Q) signal by the oscillation signal I1and the oscillation signal Q1supplied to the MIX107, and supplied to the complex filter/LPF108.

The complex filter/LPF108is a filter that limits the signal band of the frequency-converted signal. The complex filter/LPF108functions as a complex filter that limits the frequency band of the IF in a case where the IF signal is supplied from the MIX107, and functions as an LPF that limits the frequency band of the BB in a case where the first IF signal is supplied from the MIX107.

The complex filter/LPF108includes a complex filter/LPF121-1, a complex filter/LPF121-2, and a switch122.

In a case where the switch122is turned on, the complex filter/LPF121-1and the complex filter/LPF121-2function as a complex filter by sharing at least a part of signal paths for the IF(I) signal and the IF(Q) signal supplied from the MIX107and combining vectors of the signals. The complex filter/LPF121-1and the complex filter/LPF121-2limit the frequency bands of the IF(I) signal and the IF(Q) signal whose vectors are combined by sharing at least a part of the signal paths, and output the IF(I) signal and the IF(Q) signal, respectively.

In a case where the switch122is turned off, the complex filter/LPF121-1and the complex filter/LPF121-2do not share signal paths for the BB(I) signal and the BB(Q) signal supplied from the MIX107, and each function as an LPF independently. The complex filter/LPF121-1and the complex filter/LPF121-2limit the frequency bands of the BB(I) signal and the BB(Q) signal and output the BB(I) signal and the BB(Q) signal, respectively.

Under the control of the control unit24, the switch122is turned on in a case where the IF signal is supplied from the MIX107, and is turned off in a case where the first IF signal is supplied from the MIX107.

The IF(I) signal supplied from the complex filter/LPF108is output to the IQ combiner110via a terminal a of the switch109. The IF(Q) signal supplied from the complex filter/LPF108is output to the IQ combiner110via a terminal a of the switch111.

The IQ combiner110performs IQ combining of the IF(I) signal and the IF(Q) signal, generates an IF signal from which the image component has been removed, and outputs the IF signal to the IFVGA112.

The BB(I) signal supplied from the complex filter/LPF108is output to the BBVGA113via a terminal b of the switch109. The BB(Q) signal supplied from the complex filter/LPF108is output to the BBVGA114via a terminal b of the switch111.

The IFVGA112, the BBVGA113, and the BBVGA114are VGAs whose amplification degree can be varied by a control voltage that changes according to the magnitude of the supplied signal level.

The IFVGA112amplifies the IF signal supplied from the IQ combiner110and outputs the amplified IF signal to the output terminal115. The BBVGA113amplifies the BB(I) signal supplied via the switch109and outputs the amplified BB(I) signal to the output terminal116. The BBVGA114amplifies the BB(Q) signal supplied via the switch111and outputs the amplified BB(Q) signal to the output terminal117.

The output terminal115outputs the IF signal supplied from the IFVGA112to the ADC41-1of the demodulation unit22at the subsequent stage, which has been described above with reference toFIG.1. The output terminal116outputs the BB(I) signal supplied from the BBVGA113to the ADC41-2of the demodulation unit22at the subsequent stage. The output terminal117outputs the BB(Q) signal supplied from the BBVGA114to the ADC41-3of the demodulation unit22at the subsequent stage.

At present, in order to reduce the cost of a demodulation LSI that performs the demodulation processing, it is considered that the number of the ADCs41-1to41-3each having a large layout size is decreased to two.

For example, in a case where one ADC41-1is shared by the input of the IF signal and the input of the BB(I) signal, it is necessary to provide a switch for switching the input inside or outside the tuner. In a case where the switch is provided outside the tuner, an increase in cost for the switch is predicted.

Meanwhile, a configuration of the tuner is also conceivable in which the BB(I) signal and the BB(Q) signal are also output for the terrestrial digital broadcasting as for the satellite digital broadcasting. However, in addition to the IC that outputs the terrestrial wave as the IF signal, a dedicated integrated circuit (IC) that outputs both the terrestrial wave and satellite wave as the BB(I) signal and the BB(Q) signal is required.

Therefore, a tuner of the present technology includes an IF output terminal configured to output an IF signal of terrestrial broadcasting, a first output terminal configured to output the IF signal or one of BB signals that are output signals of satellite digital broadcasting and have orthogonal phases, and a second output terminal configured to output another of the BB signals.

1. First Embodiment

Configuration of Broadcast Receiving System of Present Technology

FIG.3is a block diagram illustrating a configuration example of a broadcast receiving system of the present technology.

A broadcast receiving system201inFIG.3includes a terrestrial broadcasting antenna11, a satellite digital broadcasting antenna12, a reception device211, and a display14. In the configuration illustrated inFIG.3, the same components as those described with reference toFIG.1are denoted by the same reference signs. Overlapping description will be omitted as appropriate.

The reception device211includes a tuner221, a demodulation unit222, a processing unit23, and a control unit223.

The tuner221includes one chip such as an IC. The tuner221selects the frequency of a channel desired by a user under the control of the control unit223. The tuner221amplifies an RF signal of the selected frequency and converts the frequency of the RF signal into a low frequency.

At this time, the tuner221sets whether to output a signal of a broadcast wave as an IF signal or as a BB(I) signal and a BB(Q) signal.

In a case where the frequency of a channel of terrestrial broadcasting is selected, the tuner221sets whether to output an RF signal of the terrestrial broadcasting as the IF signal or as the BB(I) signal and the BB(Q) signal under the control of the control unit223. Furthermore, the tuner221sets an output terminal from which the RF signal of the terrestrial broadcasting is output.

Furthermore, unlike the tuner21inFIG.1, the tuner221includes an output terminal that outputs the IF signal, an output terminal that outputs the BB(I) signal or the IF signal, and an output terminal that outputs the BB(Q) signal. Under the control of the control unit223, the tuner221uses an output terminal corresponding to the configuration of the demodulation unit222arranged at the subsequent stage among the three output terminals.

The demodulation unit222performs demodulation processing under the control of the control unit223. The demodulation unit222includes ADCs241-1and241-2, a demodulation processing unit242, and an error correction unit243.

The ADCs241-1and241-2convert the IF signal, the BB (I) signal, and the BB (Q) signal, which are analog signals supplied from the tuner221, into digital signals. The ADC241-1converts the IF signal or the BB (I) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit242. The ADC241-2converts the BB (Q) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit242.

The demodulation processing unit242is basically configured similarly to the demodulation processing unit42-2inFIG.1. The error correction unit243is basically configured similarly to the error correction unit43-2inFIG.1.

At the time of channel selection, the control unit223performs “control for switching between terrestrial broadcasting and satellite broadcasting”, “control for switching between IF and IQ”, “control for switching the terrestrial wave output destination”, and “control for switching between terrestrial IF and terrestrial IQ” on the tuner221.

The “control for switching between terrestrial broadcasting and satellite broadcasting” is control for setting a channel to be viewed from a terrestrial broadcasting channel and a satellite broadcasting channel. The “control for switching between IF and IQ” is control for setting whether to output the signal as the IF signal or as IQ signals. The IQ signals are BB(IQ) signals, and are a combination of a BB(I) signal and a BB(Q) signal.

The “control for switching the terrestrial wave output destination” is control for setting whether an output destination of the IF signal of the terrestrial broadcasting is the output terminal that outputs the IF signal or the output terminal that outputs the BB(I) signal. The “control for switching between terrestrial IF and terrestrial IQ” is control for setting whether to output the RF signal of the terrestrial broadcasting as the IF signal or as the BB(I) signal and the BB(Q) signal.

As described above, in the broadcast receiving system201, the tuner221includes the output terminal that outputs the BB(I) signal or the IF signal, and thus the demodulation unit222can be configured by two ADCs. As a result, the cost of the demodulation unit222can be reduced.

Note that, althoughFIG.3illustrates an example in which the tuner221includes the output terminal that outputs the BB(I) signal or the IF signal, it is sufficient that one of the terminals that output the BB(I) signal or the BB(Q) signal corresponds to the output of the IF signal. The tuner221may be configured such that the output terminal from which the tuner221outputs the BB(Q) signal can output the IF signal.

Configuration Example of Tuner

FIG.4is a diagram illustrating a configuration example of the tuner221.

The tuner221inFIG.4is different from the tuner21inFIG.2in that switches301and302are added. In the configuration illustrated inFIG.4, the same components as those described with reference toFIG.2are denoted by the same reference signs. Overlapping description will be omitted as appropriate.

Furthermore, the tuner221is provided with four control lines each of which is set to Low (L) or High (H) under the control of the control unit223at the time of channel selection. The four control lines are control lines for the four types of control in the control unit223described above. The four control lines are a control line for the “control for switching between terrestrial broadcasting and satellite broadcasting”, a control line for the “control for switching between IF and IQ”, a control line for the “control for switching the terrestrial wave output destination”, and a control line for the “control for switching between terrestrial IF and terrestrial IQ”.

The control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is connected to an RF filter105and an RF filter106.

In a case where the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L, the RF filter105filters the frequency of the RF signal supplied from an RFVGA103. In a case where the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to H, the RF filter106filters the frequency of the first IF signal supplied from an RFVGA104.

The control line for the “switching between IF and IQ” is connected to a switch122of a complex filter/LPF108and switches109and111. The switches122,109, and111are configured to synchronize.

In a case where the control line for the “switching between IF and IQ” is set to L, the complex filter/LPF108functions as a complex filter and outputs an IF(I) signal and an IF(Q) signal. In a case where the control line for the “switching between IF and IQ” is set to H, the complex filter/LPF108functions as an LPF and outputs the BB(I) signal and the BB(Q) signal.

In a case where the control line for the “switching between IF and IQ” is set to L, the switches109and111respectively output the IF(I) signal and the IF(Q) signal supplied from the complex filter/LPF108to terminals a. In a case where the control line for the “switching between IF and IQ” is set to H, the switches109and111respectively output the BB(I) signal and the BB(Q) signal supplied from the complex filter/LPF108to terminals b.

The control line for the “switching the terrestrial wave output destination” is connected to the switch301arranged at the subsequent stage of an IFVGA112.

In a case where the control line for the “switching the terrestrial wave output destination” is set to L, the switch301selects a terminal a and outputs the IF signal supplied from the IFVGA112to an output terminal115. In a case where the control line for the “switching the terrestrial wave output destination” is set to H, the switch301selects a terminal b and outputs the IF signal supplied from the IFVGA112to an output terminal116.

The control line for the “switching between terrestrial IF and terrestrial IQ” is connected to the switch301and the switch302arranged at the subsequent stage of a BBVGA113.

In a case where the control line for the “switching between terrestrial IF and terrestrial IQ” is set to L, the switch302selects a terminal a and outputs the IF signal supplied from the switch301to the output terminal116. In a case where the control line for the “switching between terrestrial IF and terrestrial IQ” is set to H, the switch302selects a terminal b and outputs the BB(I) signal supplied from the BBVGA113to the output terminal116.

The tuner221inFIG.4includes the output terminal116that outputs the IF signal or the BB(I) signal. However, while the BB(I) signal supplied from the BBVGA113is output to the output terminal116via the switch302, the BB(Q) signal supplied from a BBVGA114is directly output to an output terminal117without passing through a switch.

In the case of such a configuration inFIG.4, it is possible to output the BB(I) signal or the IF signal from the output terminal116, but a balance between the BB(I) signal and the BB(Q) signal may be deteriorated, and characteristics may be deteriorated.

Furthermore, when the user selects a channel, the control unit223controls settings of the “control for switching between terrestrial broadcasting and satellite broadcasting”, the “control for switching between IF and IQ”, the “control for switching the terrestrial wave output destination”, and the “switching between terrestrial IF and terrestrial IQ”. Therefore, the control is complicated.

Control at the Time of Channel Selection

FIG.5is a diagram illustrating values of the control lines set at the time of channel selection.

In the case of the IF output of a terrestrial wave, the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L, the control line for the “control for switching between IF and IQ” is set to L, and the control line for the “control for switching the terrestrial wave output destination” is set to L. Note that, in the case of the IF output of the terrestrial wave, the control line for the “control for switching between terrestrial IF and terrestrial IQ” is not set.

In a case where the IF signal of the terrestrial wave is output to the output terminal of the BB(I) signal, the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L, and the control line for the “control for switching between IF and IQ” is set to L. In addition, in a case where the IF signal of the terrestrial wave is output to the output terminal of the BB(I) signal, the control line for the “switching the terrestrial wave output destination” is set to H, and the control line for the “control for switching between terrestrial IF and terrestrial IQ” is set to L.

In the case of the IQ output of the terrestrial wave, the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L, the control line for the “switching between IF and IQ” is set to H, and the control line for the “switching between terrestrial IF and terrestrial IQ” is set to H. Note that, in the case of the IQ output of the terrestrial wave, the control line for the “switching the terrestrial wave output destination” is not set.

In the case of the output of a satellite wave, the control line for the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to H, the control line for the “switching between IF and IQ” is set to H, and the control line for the “switching between terrestrial IF and terrestrial IQ” is set to H. Note that, in the case of satellite output, the control line for the “switching the terrestrial wave output destination” is not set.

As described above, at the time of channel selection, combination of L and H is different for each output method of the terrestrial wave, as shown in the case of outputting the IF signal of the terrestrial wave to the output terminal of the BB(I) signal and in the case of the IQ output of the terrestrial wave, and thus, the control at the time of channel selection is complicated.

Therefore, in a second embodiment of the present technology to be described next, the tuner is provided with a control circuit for initially setting other types of control than the switching between terrestrial broadcasting and satellite broadcasting, so that only controlling the switching between terrestrial broadcasting and satellite broadcasting at the time of channel selection makes it possible to switch predetermined switches. This configuration facilitates the control at the time of channel selection.

Furthermore, a dummy switch is provided at the preceding stage of the output terminal that does not concurrently use the output of the IF signal. As a result, signal paths for the BB(I) signal and the BB(Q) signal are the same, the amplitude levels of the respective signals and the phases of the signals are maintained to be the same, and deterioration of the characteristics of the BB signals is prevented.

2. Second Embodiment

Configuration Example of Tuner

FIG.6is a diagram illustrating another configuration example of the tuner221.

The tuner221inFIG.6is different from the tuner221inFIG.4in that a dummy switch351arranged at the subsequent stage of the BBVGA114and a control circuit352are added. In the configuration illustrated inFIG.6, the same components as those described with reference toFIGS.2and4are denoted by the same reference signs. Overlapping description will be omitted as appropriate.

Furthermore, in the tuner221inFIG.6, three control lines are connected to the control circuit352from a control unit323, and internal control lines A1to D1are each connected from the control circuit352to a predetermined circuit or a predetermined switch.

The control circuit352includes an OR circuit361and an OR circuit362. The internal control line A1is connected from the control circuit352to the RF filter105and the RF filter106. The internal control line B1is connected from the OR circuit362of the control circuit352to the switches122,109, and111. The internal control line C1is connected from the OR circuit361of the control circuit352to the switch301. The internal control line D1is connected from the OR circuit362of the control circuit352to the switch302and the dummy switch351.

In the tuner221inFIG.6, as illustrated inFIG.7, the values of the “control for switching the terrestrial wave output destination” and the “control for switching between terrestrial IF and terrestrial IQ” are set in advance at the time of initial setting, such as at the time of installation or power activation. That is, in the tuner221, only the value of the “control for switching between terrestrial broadcasting and satellite broadcasting” is set at the time of channel selection. Note thatFIG.7will be appropriately referred to for describing setting of each type of control.

FIG.7is a diagram illustrating values set for each type of control and each internal control line inFIG.6.

As illustrated inFIG.7, the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave.

The “control for switching the terrestrial wave output destination” is set to L in advance in a case where the output destination is the output terminal115, and is set to H in advance in a case where the output destination is the output terminal116. The “control for switching between terrestrial IF and terrestrial IQ” is set to L in advance in the case of the IF output, and is set to H in advance in the case of the IQ output.

The values set in advance for the “control for switching the terrestrial wave output destination” and the “control for switching between terrestrial IF and terrestrial IQ” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel are supplied to the control circuit352.

As illustrated inFIG.7, the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave. Therefore, the internal control line A1is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave.

The value set in advance for the “control for switching the terrestrial wave output destination” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” are supplied to the OR circuit361. In the OR circuit361, the internal control line C1is set according to a result of an OR operation of the value set in advance for the “control for switching the terrestrial wave output destination” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel.

Therefore, as illustrated inFIG.7, the internal control line C1is set to L in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal115, and is set to H in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal116. In addition, the internal control line C1is set to H in the case of the satellite wave. Note that, in a case where the terrestrial wave is received and the IQ signals are output, the internal control line C1is not set.

The value set in advance for the “control for switching between terrestrial IF and terrestrial IQ” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” are supplied to the OR circuit362. In the OR circuit362, values of the internal control lines B1and D1are set according to a result of an OR operation of the value set in advance for the “control for switching between terrestrial IF and terrestrial IQ” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel.

Therefore, the internal control lines B1and D1are set to L in a case where the terrestrial wave is received and the IF signal is output, are set to H in a case where the terrestrial wave is received and the IQ signals are output, and are set to H in a case where the satellite wave is received.

The internal control line A1described above is connected to the RF filter105and the RF filter106.

In a case where the internal control line A1is set to L, the RF filter105filters the frequency of the RF signal supplied from the RFVGA103. In a case where the internal control line A1is set to H, the RF filter106filters the frequency of the first IF signal supplied from the RFVGA104.

The internal control line B1is connected to the switch122of the complex filter/LPF108and the switches109and111.

In a case where the internal control line B1is set to L, the complex filter/LPF108turns on the switch122to share a part of the signal paths, functions as a complex filter, and outputs the IF (I) signal and the IF (Q) signal. In a case where the internal control line B1is set to H, the complex filter/LPF108turns off the switch122, functions as an LPF without sharing the signal paths, and outputs the BB (I) signal and the BB (Q) signal.

In a case where the internal control line B1is set to L, the switches109and111respectively output the IF(I) signal and the IF(Q) signal supplied from the complex filter/LPF108to the terminals a. In a case where the internal control line B1is set to H, the switches109and111respectively output the BB(I) signal and the BB(Q) signal supplied from the complex filter/LPF108to the terminals b.

The internal control line C1is connected to the switch301arranged at the subsequent stage of the IFVGA112.

In a case where the internal control line C1is set to L, the switch301selects the terminal a and outputs the IF signal supplied from the IFVGA112to the output terminal115. In a case where the internal control line C1is set to H, the switch301selects the terminal b and outputs the IF signal supplied from the IFVGA112to the output terminal116.

The internal control line D1is connected to the switch302and the dummy switch351.

In a case where the internal control line D1is set to L, the switch302selects the terminal a and outputs the IF signal supplied from the switch301to the output terminal116. In a case where the internal control line D1is set to H, the switch302selects the terminal b and outputs the BB(I) signal supplied from the BBVGA113to the output terminal116.

In a case where the internal control line D1is set to L, the dummy switch351selects a terminal a. In a case where the internal control line D1is set to H, the dummy switch351selects a terminal b and outputs the BB(Q) signal supplied from the BBVGA114to the output terminal117.

Example 1 of Signal Flow in Tuner

FIG.8is a diagram illustrating a signal flow in the tuner in a case where the output destination of the IF signal of the terrestrial wave is the output terminal115.

InFIG.8, an arrow with an alphabet indicates the signal flow. The same applies to the following drawings.

In a case where the output destination of the IF signal of the terrestrial wave is the output terminal115, the control unit223sets the “control for switching the terrestrial wave output destination” to L and sets the “control for switching between terrestrial IF and terrestrial IQ” to L at the time of initial setting. Furthermore, at the time of channel selection, the control unit223sets the “control for switching between terrestrial broadcasting and satellite broadcasting” to L.

As indicated by an arrow P1, an RF input terminal101receives the RF signal, which is a terrestrial broadcast signal supplied from the terrestrial broadcasting antenna11, and outputs the RF signal to the RFVGA103. The RFVGA103amplifies the RF signal supplied from the RF input terminal101. The RF signal is supplied to an RF filter of a frequency band corresponding to the frequency of a selected channel among the RF filters105.

At this time, since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L and the internal control line A1is set to L, the RF filter105filters the frequency of the RF signal supplied from the RFVGA103as indicated by an arrow P2. The RF signal filtered by the RF filter105is output to a MIX107.

As indicated arrows P3, the MIX107frequency-converts the RF signal into the IF(I) signal and the IF(Q) signal by an oscillation signal I1and an oscillation signal Q1supplied to the MIX107, and outputs the IF(I) signal and the IF(Q) signal to the complex filter/LPF108.

Since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L and the “control for switching between terrestrial IF and terrestrial IQ” is set to L, the OR circuit362sets each of the internal control line B1and the internal control line D1to L.

Since the internal control line B1is set to L, the complex filter/LPF108turns on the switch122to share a part of the signal paths, functions as a complex filter, and outputs the IF(I) signal and the IF(Q) signal.

In addition, since the internal control line B1is set to L, the switches109and111respectively output the IF(I) signal and the IF(Q) signal supplied from the complex filter/LPF108to the terminals a as indicated by arrows P4.

As indicated by arrows P5, an IQ combiner110performs IQ combining of the IF(I) signal and the IF(Q) signal, generates the IF signal from which an image component has been removed, and outputs the IF signal to the IFVGA112.

As indicated by an arrow P6, the IFVGA112amplifies the IF signal supplied from the IQ combiner110and outputs the amplified IF signal to the switch301.

Since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L and the “control for switching the terrestrial wave output destination” is set to L, the OR circuit361sets the internal control line C1to L.

Since the internal control line C1is set to L, the switch301selects the terminal a and outputs the IF signal supplied from the IFVGA112to the output terminal115.

Note that, in this case, although not directly related to the signal flow, the internal control line D1is set to L, and thus the switch302selects the terminal a and the dummy switch351selects the terminal a.

Example 2 of Signal Flow in Tuner

FIG.9is a diagram illustrating a signal flow in the tuner in a case where the output destination of the IF signal of the terrestrial wave is the output terminal116that outputs the BB(I) signal.

In a case where the output destination of the IF signal of the terrestrial wave is the output terminal116, the control unit223sets the “control for switching the terrestrial wave output destination” to H and sets the “control for switching between terrestrial IF and terrestrial IQ” to L at the time of initial setting. Furthermore, at the time of channel selection, the control unit223sets the “control for switching between terrestrial broadcasting and satellite broadcasting” to L.

Note that the signal flow indicated by arrows Q1to Q5inFIG.9are basically similar to the signal flow indicated by the arrows P1to P5inFIG.8, and thus description thereof will be omitted.

As indicated by the arrows Q5, the IQ combiner110performs IQ combining of the IF (I) signal and the IF (Q) signal, generates the IF signal from which the image component has been removed, and outputs the IF signal to the IFVGA112.

As indicated by an arrow Q6, the IFVGA112amplifies the IF signal supplied from the IQ combiner110and outputs the amplified IF signal to the switch301.

Since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L and the “control for switching the terrestrial wave output destination” is set to H, the OR circuit361sets the internal control line C1to H.

Since the internal control line C1is set to H, the switch301selects the terminal b and outputs the IF signal supplied from the IFVGA112to the switch302.

Since the internal control line D1is set to L, the switch302selects the terminal a and outputs the IF signal supplied from the switch301to the output terminal116. Note that, at this time, the dummy switch351selects the terminal a.

Example 3 of Signal Flow in Tuner

FIG.10is a diagram illustrating a signal flow in the tuner in a case where the terrestrial wave is output as the IQ signals.

In a case where the terrestrial wave is output as the IQ signals, the control unit223sets the “control for switching the terrestrial wave output destination” to L and sets the “control for switching between terrestrial IF and terrestrial IQ” to H at the time of initial setting. Furthermore, at the time of channel selection, the control unit223sets the “control for switching between terrestrial broadcasting and satellite broadcasting” to L.

Note that the signal flow indicated by arrows R1and R2inFIG.10are basically similar to the signal flow indicated by the arrows P1and P2inFIG.8, and thus description thereof will be omitted.

As indicated by arrows R3, the MIX107frequency-converts the RF signal into the BB(I) signal and the BB(Q) signal by the oscillation signal I1and the oscillation signal Q1supplied to the MIX107, and outputs the BB(I) signal and the BB(Q) signal to the complex filter/LPF108.

Since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L and the “control for switching between terrestrial IF and terrestrial IQ” is set to H, the OR circuit362sets each of the internal control line B1and the internal control line D1to H.

Since the internal control line B1is set to H, the complex filter/LPF108turns off the switch122, functions as an LPF without sharing the signal paths, and outputs the BB(I) signal and the BB(Q) signal.

In addition, since the internal control line B1is set to H, the switches109and111respectively output the BB(I) signal and the BB(Q) signal supplied from the complex filter/LPF108to the terminals b, as indicated by arrows R4.

As indicated by one of arrows R5, the BBVGA113amplifies the BB(I) signal supplied from the switch109and outputs the amplified BB(I) signal to the switch302.

As indicated by one of the arrows R5, the BBVGA114amplifies the BB(Q) signal supplied from the switch111and outputs the amplified BB(Q) signal to the dummy switch351.

Since the internal control line D1is set to H, the switch302selects the terminal b and outputs the BB(I) signal supplied from the BBVGA113to the output terminal116.

Since the internal control line D1is set to H, the dummy switch351selects the terminal b and outputs the BB(Q) signal supplied from the BBVGA114to the output terminal117.

Example 4 of Signal Flow in Tuner

FIG.11is a diagram illustrating a signal flow in the tuner in a case where the satellite wave is output as the IQ signals.

In the case ofFIG.11, the “control for switching the terrestrial wave output destination” and the “control for switching between terrestrial IF and terrestrial IQ” are not particularly set at the time of initial setting. At the time of channel selection, the control unit223sets the “control for switching between terrestrial broadcasting and satellite broadcasting” to H.

As indicated by an arrow S1, a first IF input terminal102receives the first IF signal supplied from the satellite digital broadcasting antenna12, which is a signal obtained by frequency conversion on the RF signal as a satellite digital broadcast signal, and outputs the first IF signal to the RFVGA104. The RFVGA104amplifies the first IF signal supplied from the first IF input terminal102. The first IF signal is supplied to the RF filter106.

At this time, since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to H and the internal control line A1is set to H, the RF filter106filters the frequency of the first IF signal supplied from the RFVGA104, as indicated by an arrow S2. The first IF signal filtered by the RF filter106is output to the MIX107.

As indicated by arrows S3, the MIX107frequency-converts the first IF signal into the BB(I) signal and the BB(Q) signal by the oscillation signal I1and the oscillation signal Q1supplied to the MIX107, and outputs the BB(I) signal and the BB(Q) signal to the complex filter/LPF108.

Since the “control for switching between terrestrial broadcasting and satellite broadcasting” is set to H, the OR circuit362sets each of the internal control line B1and the internal control line D1to H regardless of whether the “control for switching between terrestrial IF and terrestrial IQ” is set to H or L.

Since the internal control line B1is set to H, the complex filter/LPF108turns off the switch122, functions as an LPF without sharing the signal paths, and outputs the BB(I) signal and the BB(Q) signal.

In addition, since the internal control line B1is set to H, the switches109and111respectively output the BB(I) signal and the BB(Q) signal supplied from the complex filter/LPF108to the terminals b, as indicated by arrows S4.

As indicated by one of arrows S5, the BBVGA113amplifies the BB(I) signal supplied from the switch109and outputs the amplified BB(I) signal to the switch302.

As indicated by one of the arrows S5, the BBVGA114amplifies the BB(Q) signal supplied from the switch111and outputs the amplified BB(Q) signal to the dummy switch351.

Since the internal control line D1is set to H, the switch302selects the terminal b and outputs the BB(I) signal supplied from the BBVGA113to the output terminal116.

Since the internal control line D1is set to H, the dummy switch351selects the terminal b and outputs the BB(Q) signal supplied from the BBVGA114to the output terminal117.

As described above, according to the second embodiment of the present technology, the IF signal is output from one of the terminals that output the BB(I) signal or the BB(Q) signal, and thus the number of ADCs at the subsequent stage can be reduced. As a result, the cost of a demodulation LSI can be easily reduced.

Note that, in the case of the reception device inFIG.3, the IF signal can be output from one of the terminals that output the BB(I) signal or the BB(Q) signal. However, which of the ADCs can process the IF signal depends on the configuration of the demodulation processing unit, and thus it is desirable that the IF signal can be output from both the terminals that output the BB(I) signal or the BB(Q) signal.

3. Third Embodiment

Configuration of Broadcast Receiving System of Present Technology

FIG.12is a block diagram illustrating a configuration example of a broadcast receiving system of the present technology.

A broadcast receiving system401inFIG.12includes the terrestrial broadcasting antenna11, the satellite digital broadcasting antenna12, a reception device411, and the display14. In the configuration illustrated inFIG.12, the same components as those described with reference toFIG.1or3are denoted by the same reference signs. Overlapping description will be omitted as appropriate.

The reception device411includes a tuner421, a demodulation unit422, the processing unit23, and a control unit423. In the reception device411, the tuner421is configured such that the IF signal can be output from either of both output terminals that output the BB(I) signal or the BB(Q) signal according to the configuration of the demodulation unit422.

The tuner421includes one chip such as an IC. The tuner421selects the frequency of a channel desired by a user under the control of the control unit423. The tuner421amplifies an RF signal of the selected frequency and converts the frequency of the RF signal into a low frequency.

Furthermore, unlike the tuner221inFIG.3, the tuner421includes an output terminal that outputs the IF signal, an output terminal that outputs the BB(I) signal or the IF signal, and an output terminal that outputs the BB(Q) signal or the IF signal. Under the control of the control unit423, the tuner421uses an output terminal corresponding to the configuration of the demodulation unit422arranged at the subsequent stage among the three output terminals.

The demodulation unit422performs demodulation processing in accordance with a control signal supplied from the control unit423. The demodulation unit422includes ADCs441-1and441-2, a demodulation processing unit442, and an error correction unit443.

The ADCs441-1and441-2convert the IF signal, the BB(I) signal, and the BB(Q) signal, which are analog signals supplied from the tuner421, into digital signals. The ADC441-1converts the IF signal or the BB(I) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit442. The ADC441-2converts the IF signal or the BB(Q) signal into a digital signal, and outputs the converted digital signal to the demodulation processing unit442.

The demodulation processing unit442is basically configured similarly to the demodulation processing unit42-2inFIG.1. The error correction unit443is basically configured similarly to the error correction unit43-2inFIG.1.

At the time of channel selection, the control unit423performs the “control for switching between terrestrial broadcasting and satellite broadcasting” on the tuner421.

Note that, in the tuner421, whether to output a signal of a broadcast wave as the IF signal or as the BB(I) signal and the BB(Q) signal is set in advance at the time of initial setting, as in the tuner221inFIG.6. Furthermore, in a case where the frequency of a channel of the terrestrial broadcasting is selected, whether to output the RF signal of the terrestrial broadcasting from the output terminal of the IF signal, from the output terminal of the BB(I) signal, or from the output terminal of the BB(Q) signal is also set in advance at the time of initial setting.

That is, at the time of power activation, the control unit423sets in advance the “control for switching between IF and IQ”, “control for switching the terrestrial wave output destination to I”, and “control for switching the terrestrial wave output destination to Q” as initial settings.

Note that the “control for switching the terrestrial wave output destination to I” is control for setting whether to set the output destination of the terrestrial wave as the output terminal that outputs the BB(I) signal. In addition, the “control for switching the terrestrial wave output destination to Q” is control for setting whether to set the output destination of the terrestrial wave as the output terminal that outputs the BB(Q) signal.

As described above, in the broadcast receiving system401, the tuner421includes the output terminal that outputs the BB(I) signal or the IF signal and the output terminal that outputs the BB(Q) signal or the IF signal, whereby the demodulation unit422can be configured by two ADCs. As a result, the cost of the demodulation unit422can be easily reduced.

Configuration Example of Tuner

FIG.13is a diagram illustrating a configuration example of the tuner inFIG.12.

The tuner421inFIG.13is different from the tuner21inFIG.2in that the switch109, the IQ combiner110, the switch111, the IF VGA (IFVGA)112, and the BB VGAs (BBVGAs)113and114are removed. Furthermore, the tuner421is different from the tuner21inFIG.2in that a control circuit551, an IF/IQ switching circuit552, automatic gain control (AGC) amplifiers553and554, a switch555, and a switch556are added.

Furthermore, the tuner421is provided with four internal control lines A2to D2, each of which is connected from the control circuit551to a circuit or a predetermined switch.

The control circuit551includes an OR circuit561, an OR circuit562, and an OR circuit563. The internal control line A2is connected from the control circuit551to the RF filter105and the RF filter106. The internal control line B2is connected from the OR circuit561of the control circuit551to the IF/IQ switching circuit552. The internal control line C2is connected from the OR circuit562of the control circuit551to the switch555. The internal control line D2is connected from the OR circuit563of the control circuit551to the switch556.

In the tuner421inFIG.13, as described above, the values of the “control for switching between IF and IQ”, the “control for switching the terrestrial wave output destination to I”, and the “control for switching the terrestrial wave output destination to Q” are set in advance at the time of initial setting. That is, also in the tuner421, only the value of the “control for switching between terrestrial broadcasting and satellite broadcasting” is set at the time of channel selection.

The “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave.

The “control for switching between IF and IQ” is set to L in advance in the case of the IF output, and is set to H in advance in the case of the IQ output. The “control for switching the terrestrial wave output destination to I” is set to L in advance in a case where the output destination is the output terminal115, and is set to H in advance in a case where the output destination is the output terminal116. The “control for switching the terrestrial wave output destination to Q” is set to L in advance in a case where the output destination is the output terminal115, and is set to H in advance in a case where the output destination is the output terminal117.

The values set in advance for the “control for switching between IF and IQ”, the “control for switching the terrestrial wave output destination to I”, and the “control for switching the terrestrial wave output destination to Q” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel are supplied to the control circuit551.

The “control for switching between terrestrial broadcasting and satellite broadcasting” is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave. Therefore, the internal control line A2is set to L in the case of the terrestrial wave, and is set to H in the case of the satellite wave.

The value set in advance for the “control for switching between IF and IQ” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” are supplied to the OR circuit561. In the OR circuit561, the internal control line B2is set according to a result of an OR operation of the value set in advance for the “control for switching between IF and IQ” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel. Therefore, the internal control line B2is set to L in a case where the terrestrial wave is received and the IF signal is output, is set to H in a case where the terrestrial wave is received and the IQ signals are output, and is set to H in a case where the satellite wave is received.

The value set in advance for the “control for switching the terrestrial wave output destination to I” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” are supplied to the OR circuit562. In the OR circuit562, the internal control line C2is set according to a result of an OR operation of the value set in advance for the “control for switching the terrestrial wave output destination to I” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel. Therefore, the internal control line C2is set to L in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal115, is set to H in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal116, and is set to H in a case where the satellite wave is received. Note that, in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal117, the internal control line C2is not set.

The value set in advance for the “control for switching the terrestrial wave output destination to Q” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” are supplied to the OR circuit563. In the OR circuit563, the internal control line D2is set according to a result of an OR operation of the value set in advance for the “control for switching the terrestrial wave output destination to Q” and the value set for the “control for switching between terrestrial broadcasting and satellite broadcasting” when the user selects a channel. Therefore, the internal control line D2is set to L in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal116, is set to H in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal117, and is set to H in a case where the satellite wave is received. Note that, in a case where the terrestrial wave is received and the output destination of the IF signal is the output terminal115, the internal control line D2is not set.

The internal control line A2described above is connected to the RF filter105and the RF filter106.

In a case where the internal control line A2is set to L, the RF filter105filters the frequency of the RF signal supplied from the RFVGA103. In a case where the internal control line A2is set to H, the RF filter106filters the frequency of the first IF signal supplied from the RFVGA104.

The internal control line B2is connected to the switch122of the complex filter/LPF108and the IF/IQ switching circuit552arranged at the subsequent stage of the complex filter/LPF108.

The IF/IQ switching circuit552includes a switch581, a switch582, an IQ combiner583, a switch584, and a switch585.

In a case where the internal control line B2is set to L, the complex filter/LPF108turns on the switch122to share a part of paths, functions as a complex filter, and outputs the IF(I) signal and the IF(Q) signal to the switches581and582. In a case where the internal control line B2is set to H, the complex filter/LPF108turns off the switch122, functions as an LPF without sharing the paths, and outputs the BB(I) signal and the BB(Q) signal to the switches581and582.

In a case where the internal control line B2is set to L, the switches581and582respectively output the IF(I) signal and the IF(Q) signal supplied from the complex filter/LPF108to terminals a. In a case where the internal control line B2is set to H, the switches581and582respectively output the BB(I) signal and the BB(Q) signal supplied from the complex filter/LPF108to terminals b.

The IQ combiner583combines the IF(I) signal and the IF(Q) signal supplied from the terminals a of the switches581and582, and outputs the combined IF signal to the switch584.

In a case where the internal control line B2is set to L, the switch584selects a terminal a and outputs the IF signal supplied from the IQ combiner583to the AGC amplifier553. In a case where the internal control line B2is set to H, the switch584selects a terminal b and outputs the BB(I) signal supplied from the switch581to the AGC amplifier553.

In a case where the internal control line B2is set to L, the switch585selects a terminal a and outputs the IF signal supplied from the IQ combiner583to the AGC amplifier554. In a case where the internal control line B2is set to H, the switch585selects a terminal b and outputs the BB(Q) signal supplied from the switch582to the AGC amplifier554.

The AGC amplifiers553and554each function as an IFVGA/BBVGA.

The AGC amplifier553amplifies the IF signal or the BB(I) signal from the switch584, and outputs the amplified IF signal or BB(I) signal to the switch555.

The AGC amplifier554amplifies the IF signal or the BB(Q) signal from the switch585, and outputs the amplified IF signal or BB(Q) signal to the switch556.

The internal control line C2is connected to the switch555disposed at the subsequent stage of the AGC amplifier553.

In a case where the internal control line C2is set to L, the switch555selects a terminal a and outputs the IF signal supplied from the AGC amplifier553to the output terminal115. In a case where the internal control line C2is set to H, the switch555selects a terminal b and outputs the IF signal or the BB(I) signal supplied from the AGC amplifier553to the output terminal116.

The internal control line D2is connected to the switch556.

The switch556functions as a dummy switch for adjusting the balance between the BB(I) signal and the BB(Q) signal. In a case where the internal control line D2is set to L, the switch556is turned off. In a case where the internal control line D2is set to H, the switch556is turned on, and outputs the IF signal or the BB(Q) signal supplied from the AGC amplifier554to the output terminal117.

As described above, in the broadcast receiving system401, the tuner421includes the output terminal that outputs the BB(I) signal or the IF signal and the output terminal that outputs the BB(Q) signal or the IF signal.

As a result, the IF signal can be output from any terminal of the output terminal115, the output terminal116, and the output terminal117, and an output format at the time of terrestrial wave reception can be compatible with either the IF signal or the IQ signals.

Furthermore, since the number of amplifiers of the tuner421inFIG.13is smaller by one than that of the tuner221inFIG.6, the circuit scale can be smaller and the cost can be reduced.

As described above, according to the third embodiment of the present technology, one type of tuner IC can be compatible with a demodulation LSI having any input format, and chip cost can be reduced.

Note that, in the present specification, a system means a set of a plurality of components (devices, modules (parts), and the like), and it does not matter whether or not all the components are in the same housing. Therefore, a plurality of devices housed in separate housings and connected via a network, and one device in which a plurality of modules is housed in one housing are both systems.

In addition, the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

Embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

For example, the present technology can take a configuration of cloud computing in which one function is shared and processed in cooperation by a plurality of devices via a network.

Furthermore, each step described in the above-described flowcharts can be executed by one device or shared and executed by a plurality of devices.

Moreover, in a case where one step includes a plurality of sets of processing, the plurality of sets of processing included in the one step can be executed by one device or shared and executed by a plurality of devices.

Combination Examples of Configurations

The present technology can also have the following configurations.

(1)

A tuner IC including:an IF output terminal configured to output an IF signal that is an output signal of terrestrial broadcasting;a first output terminal configured to output the IF signal or one of BB signals that are output signals of satellite digital broadcasting and have orthogonal phases; anda second output terminal configured to output another of the BB signals.
(2)

The tuner IC according to (1), further includinga first switch configured to switch an output destination of the IF signal to the first output terminal or the IF output terminal.
(3)

The tuner IC according to (2), further includinga dummy switch provided at a preceding stage of the second output terminal.
(4)

The tuner IC according to (3), further includinga control circuit configured to control switching of the first switch according to a first control signal that controls switching to the terrestrial broadcasting or the satellite digital broadcasting and a second control signal that controls switching of the output destination to the first output terminal or the IF output terminal, the first control signal being set at a time of channel selection, the second control signal being initially set.
(5)

The tuner IC according to (4), further including:a second switch configured to switch an output format of the output signal of the terrestrial broadcasting to the IF signal or the BB signals; and a third switch configured to switch an output of the first output terminal to the IF signal or the BB signals, in whichthe first output terminal outputs the IF signal or the one of the BB signals as the output signal of the terrestrial broadcasting by switching of the third switch, andthe second output terminal outputs the another of the BB signals as the output signal of the terrestrial broadcasting by switching of the dummy switch.
(6)

The tuner IC according to (5), in whichthe control circuit controls switching of the second switch, the third switch, and the dummy switch according to the first control signal and a third control signal that controls switching of the output format to the IF signal or the BB signals, the third control signal being initially set.
(7)

The tuner IC according to (2), in whichthe second output terminal outputs the another of the BB signals or the IF signal.
(8)

The tuner IC according to (7), further includinga second switch configured to switch the output destination of the IF signal to the second output terminal.
(9)

The tuner IC according to (8), further includingtwo amplifiers each provided at a preceding stage of the first switch or the second switch and configured to amplify the IF signal or the BB signals.
(10)

The tuner IC according to (9), further including:a third switch provided at a preceding stage of each of the amplifiers and configured to switch an output format of the output signal to the IF signal or the BB signals; and a fourth switch provided at a preceding stage of the first output terminal and configured to switch an output of the first output terminal to the IF signal or the BB signals, in whichthe first output terminal outputs the IF signal or the one of the BB signals as the output signal of the terrestrial broadcasting by switching of the fourth switch, andthe second output terminal outputs the IF signal or the another of the BB signals as the output signal of the terrestrial broadcasting by switching of the second switch.
(11)

A reception device including:a tuner IC including an IF output terminal configured to output an IF signal that is an output signal of terrestrial broadcasting, a first output terminal configured to output the IF signal or one of BB signals that are output signals of satellite digital broadcasting and have orthogonal phases, and a second output terminal configured to output another of the BB signals; anda demodulation unit including at least a first ADC configured to perform AD conversion on a signal supplied from the first output terminal and a second ADC configured to perform AD conversion on a signal supplied from the second output terminal.

REFERENCE SIGNS LIST

101RF input terminal102First IF input terminal103,104RFVGA105-1to105-n,106RF filter107MIX108Complex Filter/LPF109Switch110IQ combiner111Switch112IFVGA113,114BBVGA115to117Output terminal201Broadcast receiving system211Reception device221Tuner222Demodulation unit223Control unit241-1,241-2ADC301,302Switch351Dummy switch352Control circuit361,362OR circuit401Broadcast receiving system411Reception device421Tuner422Demodulation unit423Control unit441-1,441-2ADC551Control circuit552IF/IQ switching circuit553,554AGC amplifier555,556Switch561to563OR circuit581,582Switch583IQ combiner584,585Switch