KR101552358B1 - / analog/digital broadcasting receiving apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an analog / digital broadcast receiving apparatus, and more particularly, to an analog / digital broadcast receiving apparatus which receives a digital broadcast signal and an analog broadcast signal, selects an RF signal of a desired specific channel among received RF broadcast signals, A path selector for selectively outputting an IF signal input from the MOPLL unit to a digital channel or an analog channel according to a control signal; And a demodulation unit for demodulating the digital IF signal input from the path selection unit and the analog IF signal input from the analog filter unit.

Digital, Analog, Broadcast, Tuner, Path selection, Switch

Description

ANALOG / DIGITAL BROADCASTING RECEIVING APPARATUS [0001]

The present invention relates to a broadcast receiver, and more particularly, to an analog / digital broadcast receiver capable of receiving both a digital broadcast signal and an analog broadcast signal.

Recently, the digitization of television broadcasts such as digital satellite broadcasts and digital terrestrial broadcasts is rapidly proceeding, and the transition from analog broadcasts to digital broadcasts is expected to proceed completely.

However, since the conventional analog broadcasting is not immediately stopped even if the digitization of the television broadcasting proceeds, analog broadcasting and digital broadcasting coexist in the transition from analog broadcasting to digital broadcasting.

For this reason, broadcast receivers capable of receiving both analog broadcasts and digital broadcasts are now in widespread use.

In the case of the analog / digital dual-use television, an analog / digital common tuner is generally used, and a demodulation IC for demodulating analog and digital broadcasting signals is located at the rear end of the tuner.

In the case of the demodulator IC, the analog demodulation unit and the digital demodulation unit are separated and used by multifunction, but in the case of the new IC, it is possible to demodulate analog and digital broadcasting with one demodulation IC.

However, by using one demodulation IC, it is possible to reduce the size of the receiving device and to secure the price competitiveness. However, there is a case where loss occurs (trade off) between the analog and digital broadcasting signals as they are all demodulated .

For example, when an IC is developed based on an analog function, a problem may arise in digital signal processing, and when an IC is developed by a digital function forgery, a problem may arise in analog signal processing.

The present invention provides an analog / digital broadcast receiving apparatus capable of ensuring the best performance by preventing mutual loss due to trade off of analog and digital performance in analog and digital signal processing in an analog / digital combined receiving apparatus .

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the particular embodiments that are described. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, There will be.

According to an aspect of the present invention, there is provided an analog / digital broadcast receiving apparatus for receiving a digital broadcast signal and an analog broadcast signal, selecting an RF signal of a desired specific channel from the received RF broadcast signal, MOPLL portion; A path selector for selectively outputting the IF signal input from the MOPLL unit to a digital channel or an analog channel according to a control signal; An analog filter unit provided on the analog channel for intercepting and outputting an IF signal of a predetermined frequency band among IF signals input from the path selector; And a demodulator for demodulating the digital IF signal input from the path selector and the analog IF signal input from the analog filter.

Specifically, the path selector may include: a first switch unit provided between the output terminal of the MOPLL unit and the analog filter unit and opening / closing the analog channel according to a control signal; And a second switch unit provided between the output terminal of the MOPLL unit and the demodulation unit for opening and closing the digital channel according to the control signal.

As described above, according to the present invention, the analog and digital IF lines are separated from the rear end of the MOPLL unit, and when the analog broadcasting or the digital broadcasting is selected, the corresponding IF line is turned on, There is an advantage.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference symbols whenever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a block diagram showing an analog / digital combined receiving apparatus according to the present invention. The receiving apparatus 1 includes a MOPLL unit 10, a filter unit 20, and a demodulation unit 30.

The MOPLL unit (Mixer Oscillator Phase Locked Loop) 10 includes a mixer, a VCO, and a PLL. The MOPLL unit 10 selects an RF signal of a specific channel selected by the user among the input RF broadcast signals, (IF signal) of an analog / digital common signal.

The filter unit 20 is constituted by an LC parallel resonance circuit which cuts off a specific frequency band of the analog or digital IF signal outputted from the MOPLL unit 10 and outputs it. The LC parallel resonance circuit may be installed as a multi-stage trap (21, 22) and operates as a band stop filter.

The demodulation unit 30 is analog / digital common for demodulating an analog or digital IF signal inputted through the filter unit 20 and outputting a video and an audio signal.

The receiving apparatus 1 configured as shown in FIG. 1 transmits the IF signal to the demodulator 30 through the same IF transmission line regardless of the analog broadcasting and the digital broadcasting channel selection.

Since the analog IF signal and the digital IF signal have different characteristics such as the frequency band and the like, when using the same transmission circuit, problems may occur in signal processing in the demodulation unit in the subsequent stage.

2 is a block diagram of an analog / digital combined receiving apparatus according to the present invention. The receiving apparatus 100 includes a MOPLL unit 110, a path selector 130, an analog filter unit 150, and a demodulator 170, .

The MOPLL unit 110 includes a local oscillator 111 and a mixer 115. The MOPLL unit 110 receives a digital broadcast signal and an analog broadcast signal, It is an analog / digital common for selecting an RF signal and converting it to an intermediate frequency signal (IF signal) and outputting it.

The local oscillator 111 generates a local signal LO1 for channel tuning for a selected channel under the control of a controller (not shown). The local oscillator 111 may include a Voltage Controlled Oscillator (VCO) and a Frequency-Phase Locked Loop (FPLL), and the local signal may vary in frequency depending on a channel selected by a user.

The mixer 115 combines the input RF signal with a local signal for a selected channel input from the local oscillator 111, downconverts the IF signal into a required IF signal, and outputs the IF signal. The mixer 115 may be configured as a plurality of cases, and at least one of an upconversion mixer, a downconversion mixer, and a quadrature mixer (I, Q signal) may be mixed.

The MOPLL unit 110 may further include an AGC (Automatic Gain Control) amplifier for automatically controlling the gain of the IF signal output from the mixer 115 according to a control signal.

The path selection unit 130 variably controls the transmission line of the IF signal output from the MOPLL unit 110 according to a control signal (Control) input from the outside, Or the digital channel D_IF. The control signal may be input from a control unit (not shown) or a demodulation unit 170 or the like.

The analog filter unit 150 is provided on the analog channel and intercepts the predetermined IF signal of the IF signal input from the path selector 130 and outputs the IF signal. The analog filter unit 150 may be one of a SAW filter, an LC filter, a ceramic filter, or an analog IC filter.

The demodulator 170 is analog / digital common for demodulating the digital IF signal input from the path selector 130 or the analog IF signal input from the analog filter 150 and outputting the video and audio signals.

As described above, according to the present invention, the analog and digital IF lines are separated from the rear end of the MOPLL unit 110 through the path selection unit 130, and when the analog broadcasting or the digital broadcasting is selected, the corresponding IF line is turned on, All the broadcast signals can be processed at the best.

3 is a circuit diagram showing a detailed configuration of the path selection unit and the analog filter unit of FIG. 2 according to the embodiment of the present invention.

The path selecting unit 130 includes a first switch unit 131 and a second switch unit 135. The first switch unit 131 and the second switch unit 135 include a switching diode .

The first switch unit 131 includes a first diode D1 which is provided between the output terminal of the MOPLL unit 110 and the analog filter unit 150 and opens and closes the analog channel A_IF according to a control signal. That is, the first switch unit 131 includes a first capacitor C1 provided between the output terminal of the MOPLL unit 110 and the first node Nd1 and a second capacitor C1 connected between the output node of the MOPLL unit 110 and the first node Nd1 as a common node, (R1, R2) connected between an input terminal and a low potential and a control signal Control (Control) applied to the first node Nd1 in the forward direction between the first node Nd1 and the input terminal of the analog filter unit 150, And a first diode D1 that opens and closes the analog channel according to the control signal.

The second switch unit 135 includes a second diode D2 which is provided between the output terminal of the MOPLL unit 110 and the demodulating unit 170 and opens and closes the digital channel D_IF according to a control signal. The second switch unit 135 includes a second capacitor C2 connected between the output terminal of the MOPLL unit 110 and the second node Nd2 and a second capacitor C2 connected between the output node of the MOPLL unit 110 and the second node Nd2, A control signal Control provided in forward direction between the second node Nd2 and the input terminal of the demodulator 170 and applied to the second node Nd2, And a second diode D2 for opening and closing the digital channel in accordance with the control signal.

When the control signal applied to the first node Nd1 is high, the analog channel is turned on. When the control signal applied to the second node Nd2 is high, the digital channel is turned on. The control signals applied to the first node Nd1 and the second node Nd2 have different voltage levels. When any one of the control signals is turned on, the other channels are off.

3, the first switch unit 131 and the second switch unit 135 are operated by receiving different control signals. However, the first switch unit 131 and the second switch unit 135 are controlled by the same control And the switch unit may be configured to receive an inverted control signal through an inverter.

The analog filter unit 150 is provided on the analog channel A_IF for blocking and outputting an IF signal of a predetermined frequency band among the IF signals input from the path selector 130. The analog filter unit 150 includes an LC parallel resonance circuit C11 / L11, C12 / L12). The LC parallel resonance circuit is a band stop filter provided with a plurality of traps 151 and 152. The LC parallel resonance circuit of each of the traps 151 and 152 blocks signals of different frequency bands .

Accordingly, in the present invention, a control signal for selecting a corresponding IF transmission line according to a broadcast selected at the time of selecting an analog broadcast or a digital broadcast is transmitted to the first switch unit 131 or the second switch unit 135 ) To selectively turn on an analog channel or a digital channel. As a result, the analog and digital IF signals are supplied to the demodulator 170 through the optimal transmission line and circuit, so that the analog and digital IF signals can be processed at the best.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined by the appended claims. It will be possible. The scope of the present invention is defined by the appended claims, and all differences within the scope of the claims are to be construed as being included in the present invention.

1 is a block diagram of an analog / digital combined receiving apparatus according to the present invention.

2 is a block diagram showing an analog / digital combined receiving apparatus according to the present invention.

3 is a circuit diagram showing the detailed configuration of the path selection unit and the analog filter unit of FIG. 2 according to the embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

100: receiving apparatus 110: MOPLL unit

130: path selection unit 131: first switch unit

135: second switch unit 150: analog filter unit

170: Demodulator

Claims (7)

A MOPLL unit for receiving a digital broadcast signal and an analog broadcast signal, selecting an RF signal of a specific channel among the received RF broadcast signals, converting the selected RF signal into an IF signal, and outputting the IF signal; A path selector for selectively outputting the IF signal input from the MOPLL unit to a digital channel or an analog channel according to a control signal; An analog filter unit provided on the analog channel for intercepting and outputting an IF signal of a predetermined frequency band among IF signals input from the path selector; And And a demodulator for demodulating the digital IF signal input from the path selector and the analog IF signal input from the analog filter, Wherein the path selecting unit comprises: And a first switch unit provided between the output terminal of the MOPLL unit and the analog filter unit for opening and closing the analog channel according to the control signal, Wherein the first switch unit comprises: A first capacitor provided between an output terminal of the MOPLL unit and a first node; A voltage dividing resistor connected between the control signal input terminal and the low potential with the first node as a common node; And And a first diode installed in a forward direction between the first node and an input terminal of the analog filter unit and opening / closing an analog channel according to a control voltage applied to the first node. The method according to claim 1, Wherein the path selection unit includes a switch unit for opening / closing a digital channel or an analog channel in accordance with a control signal. The method according to claim 1, Wherein the path selector further comprises a second switch unit provided between an output terminal of the MOPLL unit and the demodulation unit and for opening and closing a digital channel in accordance with a control signal. The method of claim 3, Wherein the first switch unit and the second switch unit each include a switching diode. delete The method of claim 3, The second switch unit includes: a second capacitor provided between an output terminal of the MOPLL unit and a second node; A voltage dividing resistor connected between the control signal input terminal and the low potential with the second node as a common node; And a second diode installed in a forward direction between the second node and an input terminal of the demodulation unit and opening / closing a digital channel according to a control voltage applied to the second node. The method according to claim 1, Wherein the analog filter section includes a multi-stage LC parallel resonance circuit.

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