KR101841025B1 - tuner module - Google Patents

Abstract

A tuner module according to an embodiment of the present invention includes: a signal receiver for receiving a signal; An RF amplifier circuit for amplifying and outputting a signal received through the signal receiver; And an intermediate frequency circuit section for tuning the signal amplified by the RF amplification circuit section to an intermediate frequency signal and outputting the same; A SAW filter unit for filtering only a band of a specific broadcast frequency signal from the intermediate frequency signal output from the intermediate frequency circuit unit and outputting the filtered signal; A demodulator for demodulating and outputting the filtered broadcast frequency signal; And an IF matching unit disposed between the intermediate frequency circuit unit and the SAW filter unit and controlling IF matching.

Description

Tuner module < RTI ID =

The present invention relates to a tuner module.

Generally, a tuner includes a digital tuner for receiving a digital broadcast, an analog tuner for receiving an analog broadcast, and an analog / digital tuner for receiving both analog broadcast and digital broadcast. The analog / digital tuner that receives both the analog broadcast and the digital broadcast is provided with a digital saw (SAW) filter that passes only a signal of the input digital broadcast frequency band and an analog saw (SAW) filter that passes only the analog broadcast frequency band .

Conventional tuner uses AGC detection (Detector) inside MOPLL IC for digital and analog operation to realize performance by operating RF amplification degree differently according to input signal size. Assuming that the bandwidth of the IF tuning circuit is North American and Korean tuner, it should have a minimum of 6 MHz and actually be designed to be about 10 MHz.

The North American and Korean tuners must have a bandwidth of at least 6 MHz because they have to cover the digital signal data and analog picture from picture to sound. Accordingly, the AGC detector inside the MOPLL IC detects the AGC through the tuning circuit having a bandwidth of about 10 MHz, and the RF amplification is determined by the feedback of the RF amplification circuit. The signal due to the adjacent signal interference and interference When there is interference, the AGC of the signal alone is not Detect, and the noise component due to the signal interference hinders the accurate detection of the AGC, so that the performance of the adjacent and interference characteristics deteriorates.

If the performance of adjacent or interference characteristics deteriorates, noise may be generated on the screen, which may cause a serious impact on performance.

Embodiments can provide a tuner module that can improve adjacent and interfering interference problems.

A tuner module according to an embodiment of the present invention includes: a signal receiver for receiving a signal; An RF amplifier circuit for amplifying and outputting a signal received through the signal receiver; And an intermediate frequency circuit section for tuning the signal amplified by the RF amplification circuit section to an intermediate frequency signal and outputting the same; A SAW filter unit for filtering only a band of a specific broadcast frequency signal from the intermediate frequency signal output from the intermediate frequency circuit unit and outputting the filtered signal; A demodulator for demodulating and outputting the filtered broadcast frequency signal; And an IF matching unit disposed between the intermediate frequency circuit unit and the SAW filter unit and controlling IF matching.

The embodiment can provide a tuner module capable of improving the adjacent and interference interference problems by feeding back the detection signal of the demodulation unit to the RF amplification circuit unit.

1 illustrates a tuner module according to an embodiment of the present invention.
Figure 2 shows an IF matching unit according to an embodiment of the invention;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The details of other embodiments are included in the detailed description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. Like reference numerals refer to like elements throughout the specification.

FIG. 1 is a diagram for explaining a tuner module according to an embodiment of the present invention, and FIG. 2 is a diagram showing an IF matching unit according to an embodiment of the present invention. 1 and 2, the tuner according to the embodiment includes an LNA 200, a filter 201, an ANT tuning circuit 202, an RF amplifying circuit 210, an RF tuning circuit 204, An IF matching circuit 225, an IF matching unit 250, a SAW filter 230, and a demodulation unit 240. The circuit unit 220 includes an input /

The LNA (Low Noise Amplifier) 200 has characteristics of a low noise ratio and a high amplification degree and selectively operates, and low-noise amplifies a high frequency signal received from the antenna.

The LNA 200 selectively operates by the supplied DC voltage. When the received high frequency signal is a weak electric field, the low noise amplification is performed. When the received high frequency signal is a strong electric field, the LNA 200 is turned off and bypassed . A bypass path may be formed in the LNA 200.

The IF filter 201 passes a signal of a required frequency band through a circuit having a good frequency selectivity. The IF filter 201 may include a serial resonant circuit or a parallel resonant circuit.

The ANT tuning circuit 202 includes a circuit for impedance matching between the IF filter 201 and the RF amplifier circuit 210 and is designed to minimize insertion loss.

The RF amplification circuit 210 includes a circuit for amplifying an RF signal, and changes the amplification degree of the RF signal according to an input automatic gain control (AGC) signal.

The RF tuner circuit 204 includes a double tuning circuit to select a desired RF signal and make the frequency characteristic flat.

On the other hand, the receiving apparatus including the tuning circuit and the amplifying circuit can receive a broadcast signal transmitted at a frequency of a plurality of bands, for example, receive a UHF signal, a VHF-High signal and a VHF- have.

The intermediate frequency circuit unit 220 may receive the amplified signal through the RF amplification circuit 210 and may output the tuned signal as an intermediate frequency signal. The intermediate frequency circuit unit 220 may convert a signal received from the RF amplification circuit 210 into an intermediate frequency signal corresponding to a desired broadcast channel and output the intermediate frequency signal. The intermediate frequency circuit unit 220 may be configured as an MOPLL integrated circuit.

The intermediate frequency circuit unit 220 may include an AGC detection unit 221, an ADC unit 222, and a port unit 223.

The AGC detector 221 detects a signal provided from the RF amplifier circuit 210 and converts the AGC signal into an AGC signal according to the level of the detected signal to output the AGC signal to the RF amplifier circuit 210 .

The AGC detector 221 converts an AGC signal into an AGC signal according to the level of the signal and provides the AGC signal to the RF amplifier circuit 210 to adjust the amplification degree. That is, in the strong signal condition, the AGC signal is outputted to the vicinity of 0 V to suppress the amplification of the RF amplification circuit 210 to the maximum, while when the AGC signal is in the weak electric field signal condition, the AGC signal is outputted to the vicinity of 4 V The amplification of the RF amplification circuit 210 can be maximized.

The ADC (Analog to Digital Converter) 222 converts the AGC signal provided from the AGC detector 221 into an ADC signal and outputs the ADC signal. That is, the ADC unit 222 may output an ADC signal of five levels from 0 to 4 by connecting to an AGC signal provided by the AGC detector 221. [ Accordingly, the level of the signal is detected and converted to the AGC signal, and the AGC signal is output again to the ADC signal, so that the condition of the signal can be grasped through the ADC signal.

The port unit 223 senses whether the signal is a strong signal or weak electric signal through the ADC signal provided by the ADC unit 222 and outputs the signal to the switching unit 260 according to the strong signal or weak electric field signal. Can be controlled. That is, after the port unit 223 senses whether the signal is a strong signal or weak signal through the ADC signal, the port unit 223 turns off the switching unit 260 and outputs a weak signal The switching unit 260 may be turned on.

Accordingly, in the case of a weak electric field signal, a signal can pass through the LNA unit 200 as the switching unit 260 is turned on, so that the digital weak electric field sensitivity standard and the analog weak electric field The reception performance can be improved. In the case of the strong signal, the signal is not passed through the LNA unit 200 as the switching unit 260 is turned off, It is possible to prevent a side effect that deteriorates the analog characteristics of the input signal.

The IF signal output from the intermediate frequency circuit unit 220 may be tuned and amplified and outputted by the IF tuning circuit 225.

The SAW filter 230 may output only the band of the digital broadcast frequency signal from the intermediate frequency signal output from the intermediate frequency circuit unit 220 or may pass the band of the analog broadcast frequency signal through the intermediate frequency signal.

When the switching unit 260 is turned off, the signal does not pass through the LNA unit 200, so that the value of the gain input to the RF automatic gain control and demodulation unit 240 varies due to the adjacent channel. Accordingly, the signal to noise ratio (SNR) of the demodulator 240 changes according to the application of the interfering waves, resulting in the generation of attenuation noise on the screen.

In the embodiment of the present invention, when the adjacent signal is received while the switching unit 260 is turned off and the signal does not pass through the LNA unit 200, the signal-to-noise ratio changes due to a change in gain value, The RF gain value of the demodulation unit 240 is monitored.

For this purpose, an IF matching unit 250 may be formed between the IF tuning circuit 225 and the SAW filter 230 for IF matching.

When the adjacent signal is applied, the RF automatic gain control value is changed in the demodulation unit 240. When the RF automatic gain control value is compared with the RF automatic gain control value before the adjacent signal is applied, the IF matching unit 250 outputs the IF gain value And the signal-to-noise ratio can be reduced by controlling the RF automatic gain control value of the demodulation unit 240 by changing the RF automatic gain control value.

The IF matching unit 250 is disposed between the IF tuning circuit 225 and the SAW filter 230 and adjusts the IF matching by adjusting the resistor R1 and the capacitor C1 and the inductor L1. have.

That is, the capacitance of the capacitor C1 and the inductance of the inductor L1 are adjusted to pass the band of the frequency signal outputted from the IF tuning circuit 225. The signal passing through the capacitor C1 and the inductor L1 may be connected to the base end of the transistor TR1. The signal passed through the demodulator 240 may be connected to the emitter terminal of the transistor TR1.

When the signal input to the base end of the transistor TR1 is equal to or lower than the operating voltage of the transistor TR1, the transistor TR1 is not operated but inputted to the SAW filter 230. However, The transistor TR1 operates so that the IF gain value is changed.

The demodulator 240 may demodulate and output an analog broadcast frequency signal or a digital broadcast frequency signal filtered by a filter. At this time, the demodulation unit 240 may demodulate the analog / digital broadcast frequency signal into analog / digital audio and analog / digital video signals desired by the program and output the analog / digital broadcast frequency signal.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (7)

An RF amplifier circuit for amplifying and outputting a signal received through the signal receiver;
An intermediate frequency circuit unit for converting a signal input from the RF amplification circuit unit into an intermediate frequency signal and outputting the intermediate frequency signal;
A SAW filter unit for passing only a specific broadcast frequency signal band from an intermediate frequency signal output from the intermediate frequency circuit unit;
A demodulator for demodulating and outputting the filtered broadcast frequency signal;
And an IF matching unit disposed between the intermediate frequency circuit unit and the SAW filter unit for adjusting a resistance, a capacitor, and an inductor to pass a band of a frequency signal output from the RF amplifying circuit,
The intermediate frequency circuit section
An automatic gain control value detector for calculating an automatic gain control value for a signal output from the RF amplifier circuit;
And a port unit for detecting the electric field intensity according to the automatic gain control value and controlling the switching unit according to the detection result,
The switching unit
And a control unit which is disposed between the signal receiving unit and the RF amplification circuit unit and is turned on when the weak electric field is controlled based on the control of the port unit and is turned off in a strong electric field to output the received signal to the RF amplification circuit unit,
Wherein the demodulation unit checks an adjacent signal reception and automatic control gain value and compares an automatic gain control value before the adjacent signal is applied and an automatic gain control value after the adjacent signal is applied when the switching is turned off,
Wherein the IF matching unit changes an IF gain value when a signal adjusted by the capacitor and the inductor is input to the transistor based on the comparison result and the input signal is equal to or greater than the operating voltage of the transistor, A tuner module for controlling the tuner module. The method according to claim 1,
And an IF match circuit formed between the intermediate frequency circuit section and the IF matching section. The method according to claim 1,
And the automatic gain control value detected by the automatic gain control value detector is output to the RF amplifier. delete delete delete delete

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