KR20020078482A - Combination tuner for earth and satellite broadcasting - Google Patents

Abstract

PURPOSE: A combi-tuner for ground and satellite broadcasting is provided to receive both of ground wave and satellite wave. CONSTITUTION: A combi-tuner for ground and satellite broadcasting includes a satellite frequency output unit for receiving satellite wave to output a predetermined frequency, the first switch(115) for selectively outputting a radio-frequency signal inputted from an antenna(ANT1) or the radio-frequency signal output from the satellite frequency output unit to an AGC(101), and the second switch(116) for selectively providing the second IF frequencies output from a mixer. The tuner further includes the first low pass filter(117) for passing only the frequency of 10MHz among the second IF frequencies output from the second switch, and the second low pass filter for passing only the frequencies of 10-45MHz among the second IF frequencies output from the second switch.

Description

Combination tuner for terrestrial and satellite broadcasting {COMBINATION TUNER FOR EARTH AND SATELLITE BROADCASTING}

The present invention relates to a tuner, and more particularly, to a combination tuner for terrestrial and satellite broadcasts to selectively receive terrestrial and satellite broadcasts.

In general, a tuner includes a single conversion type for outputting an IF frequency and a double conversion method for amplifying and mixing a primary IF frequency signal and then converting the signal into a secondary IF frequency for detection. The double conversion tuner is further divided into a terrestrial tuner and a satellite tuner.

As shown in FIG. 1, the double-conversion terrestrial tuner 10 includes an AGC 2, a tracking filter 3, an RF amplifier 4, an RF filter 5, and a primary mixer 6. ), Primary local oscillator (7), primary PLL (8), primary IF filter (9), primary IF amplifier (10), secondary mixer (11), secondary local oscillator And a second order PLL 13 and a second order IF filter 14.

First, the AGC 2 automatically adjusts the output of the video signal at all times even when the magnitude of the high frequency signal of 44 to 860 MHz that is induced by the antenna ANT changes.

The tracking filter 3 removes noise included in the signal of the high frequency band received by the antenna ANT and passes only the desired high frequency (RF) signal.

The RF amplifier 4 amplifies the high frequency signal passed through the tracking filter 3.

The RF filter 5 selects a desired high frequency signal (860 MHz) from the high frequency signals amplified by the RF amplifier 4.

The primary mixer 6 outputs the primary IF frequency by mixing the high frequency signal selected by the RF filter 5 and the oscillation frequency generated by the primary local oscillator 7.

The primary local oscillator 7 generates a predetermined oscillation frequency according to the control voltage of the primary PLL 8 at the time of channel selection and outputs it to the primary mixer 6.

The primary phase locked loop (PLL) 8 stores channel data therein and outputs a control voltage to the primary local oscillator 7 according to external control.

The primary IF filter 9 passes only the desired IF frequency signal of the primary IF frequency signals output from the primary mixer 6.

The primary IF amplifier 10 amplifies the primary IF frequency signal output from the primary IF filter 9.

In addition, the secondary mixer 11 mixes the primary IF frequency signal amplified by the primary IF amplifier 10 and the oscillation frequency generated by the secondary local oscillator 12 to output the secondary IF frequency.

The secondary local oscillator 12 generates a predetermined oscillation frequency according to the control voltage of the secondary PLL 13 at the time of channel tuning and outputs it to the secondary mixer 11.

The secondary phase locked loop (PLL) 13 stores channel data therein and outputs a control voltage to the secondary local oscillator 12 according to external control.

The secondary IF filter 14 passes only signals of a desired band among the secondary IF frequency signals output from the secondary mixer 11.

When the tuner 10 of the double conversion method makes a desired tuning waveform in the AGC 2, the RF amplifier 3, and the RF filter 4 when tuning a desired channel among the TV signals input from the antenna ANT, This passes through the primary mixer 6 and then up-converts to the primary IF frequency (1038 MHz) in the primary IF amplifier 10, which in turn passes through the secondary mixer 11 and then the secondary IF filter 14. Downconvert to the final IF frequency (44MHz) at.

Meanwhile, the double-conversion satellite tuner has the same configuration as a conventional terrestrial tuner but has different frequencies for frequency conversion and down-conversion.

However, when the conventional double-conversion terrestrial tuner and satellite tuner are applied to one device, each tuner is used, thereby increasing the manufacturing cost and increasing its volume.

Accordingly, an object of the present invention is to provide a combination tuner for terrestrial and satellite broadcasting that can receive both terrestrial and satellite waves.

1 is a block diagram showing the configuration of a conventional double-conversion terrestrial tuner.

Figure 2 is a block diagram showing the configuration of the terrestrial and satellite broadcasting combination tuner according to an embodiment of the present invention

3 is a block diagram showing the configuration of a terrestrial and satellite broadcasting combination tuner according to another embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: Combination tuner for terrestrial and satellite broadcasting

101: AGC 102 first amplifier

103: first low pass filter 104: first mixer

105: first local oscillator 106: first PLL

107: band pass filter 108: second amplifier

109: second mixer 110: the second local oscillator

111: second PLL112: third mixer

113: third local oscillator 114: third PLL

115: first switch 116: second switch

117: second band pass filter 118: third band pass filter

Features of the present invention for achieving the above object,

The first antenna, the AGC, the first amplifier, the first low pass filter, the first mixer, the first local oscillator, the first PLL, the band pass filter, the second amplifier, and the second mixer A double conversion tuner comprising a second local oscillator and a second PLL,

A satellite frequency output unit for receiving a satellite wave and outputting a predetermined frequency;

First switching means for selectively outputting a high frequency signal input from the first antenna or a high frequency signal output from the satellite frequency output unit to the AGC by being switched by a control signal input from the outside;

Second switching means for selectively supplying a second IF frequency which is switched according to an external control signal and output from the second mixer;

A second low pass filter for passing only a frequency in a 10 MHz band of the second IF frequencies output from the second switching means;

And a third low pass filter configured to pass only a frequency in a 10 to 45 MHz band among the second IF frequencies output from the second switching means.

Here, the satellite frequency output unit,

A second antenna for receiving satellite waves,

A third mixer for mixing a high frequency signal input through the second antenna and an oscillation frequency input from the outside to output a predetermined frequency;

A third local oscillator for generating a predetermined oscillation frequency according to a control voltage input from the outside and outputting the oscillation frequency to the third mixer;

And a third PLL for outputting a control voltage to the third local oscillator.

Here, the third local oscillator generates an oscillation frequency by adding a signal of 479.5 MHz to the high frequency signal flowing through the second antenna.

Here, the first low pass filter passes only a high frequency signal of 860MHz or less.

Here, the first switching means is any one fixed contact is connected to the output terminal of the first antenna, the other fixed contact is connected to the output terminal of the third mixer of the satellite frequency output unit is input from the outside The control contact switches the movable contact connected to the AGC.

Here, the second switching means has a movable contact connected to an output terminal of the second mixer, any one fixed contact connected to the second low pass filter, and the other fixed contact connected to the third low pass filter. This connection is switched according to an external control signal to selectively supply the second IF frequency output from the second mixer to the second low pass filter or the third low pass filter.

Here, the first switching means and the second switching means are switched under the control of the QAM or QPSK of the system.

Another feature of the invention,

The first antenna, the AGC, the first amplifier, the first low pass filter, the first mixer, the first local oscillator, the first PLL, the band pass filter, the second amplifier, and the second mixer A double conversion tuner comprising a second local oscillator and a second PLL,

A satellite frequency output unit for receiving a satellite wave and outputting a predetermined frequency;

First switching means for selectively outputting a second IF frequency input from the second mixer or a high frequency signal output from the satellite frequency output unit by a control signal input from the outside;

Second switching means for selectively supplying a second IF frequency which is switched according to an external control signal and output from the first switching means,

A second low pass filter for passing only a frequency in a 10 MHz band of the second IF frequencies output from the second switching means;

And a third low pass filter configured to pass only a frequency in a 10 to 45 MHz band among the second IF frequencies output from the second switching means.

Here, the satellite frequency output unit,

A second antenna for receiving satellite waves,

A third mixer for mixing a high frequency signal input through the second antenna and an oscillation frequency input from the outside to output a predetermined frequency;

A third local oscillator for generating a predetermined oscillation frequency according to a control voltage input from the outside and outputting the oscillation frequency to the third mixer;

And a third PLL for outputting a control voltage to the third local oscillator.

Here, the third local oscillator generates an oscillation frequency by adding a signal of 479.5 MHz to the high frequency signal flowing through the second antenna.

Here, the first low pass filter passes only a high frequency signal of 860MHz or less.

Here, the first switching means is connected to the output terminal of the second mixer, the movable contact, any one of the fixed contact is connected to the output terminal of the third mixer of the satellite frequency output unit, the input terminal of the second switching means Another fixed contact is connected.

Here, the second switching means is connected to any one of the fixed contact of the first switching means, the movable contact is connected to any one of the fixed contact, the second low pass filter, the third low pass filter The other fixed contact is connected and switched according to an external control signal to selectively supply a second IF frequency output from the second mixer to the second low pass filter or the third low pass filter.

Here, the first switching means and the second switching means are switched under the control of the QAM or QPSK of the system.

<First Embodiment>

Hereinafter, the configuration of a terrestrial and satellite broadcasting combination tuner according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram showing the configuration of a terrestrial and satellite broadcasting combination tuner according to an embodiment of the present invention.

Referring to FIG. 2, the terrestrial and satellite broadcasting combination tuner 100 according to the present invention includes a first antenna ANT 1, a second antenna ANT 2, an AGC 101, and a first amplifier 102. ), A first low pass filter 103, a first mixer 104, a first local oscillator 105, a first PLL 106, a band pass filter 107, and a second amplifier ( 108, the second mixer 109, the second local oscillator 110, the second PLL 111, the third mixer 112, the third local oscillator 113, and the third PLL ( 114, a first switch 115, a second switch 116, a second low pass filter 117, and a third low pass filter 118.

The first antenna ANT 1 receives terrestrial waves of 44 to 860 MHz, and the second antenna ANT 2 receives satellite waves of 950 to 2150 MHz.

The third mixer 112 mixes the high frequency signal input through the second antenna ANT 2 and the oscillation frequency input from the third local oscillator 113 and outputs a high frequency signal of 479.5 MHz.

The third local oscillator 113 generates an oscillation frequency obtained by adding a high frequency signal and 479.5 MHz according to the control voltage input from the third PLL 114, and outputs the oscillation frequency to the third mixer 112. The feedback of the voltage of the third local oscillator 113 is fed back to output the control voltage to the third local oscillator 113.

The first switch 115 has a fixed contact is connected to the output terminal of the first antenna (ANT 1), b fixed contact is connected to the output terminal of the third mixer 112, the movable contact by a control signal input from the outside The switch selectively outputs the high frequency signal input from the first antenna ANT 1 or the IF frequency output from the third mixer 112 to the AGC 101. Here, the first switch 115 is switched under the control of the QAM or QPSK of the system, and the movable contact is changed in conjunction with the second switch 116.

The AGC 101 is connected to the movable contact of the first switch 115 so that the output of the video signal is always automatically automatically gain adjusted even if the magnitude of the high frequency signal input through the first switch 115 changes, and the first amplifier 102 amplifies the high frequency signal passed through the AGC 101, and the first low pass filter 103 passes only the high frequency signal of 860 MHz or less among the high frequency signals amplified by the first amplifier 102.

The first mixer 104 mixes the high frequency signal selected by the first low pass filter 103 and the oscillation frequency input from the first local oscillator 105, upconverts to the first IF frequency of 1038 MHz, and outputs the first frequency. The local oscillator 105 generates a predetermined oscillation frequency according to the control voltage supplied from the first PLL 106 at the time of channel tuning and outputs the oscillation frequency to the first mixer 104. The first PLL 106 is the first local oscillator. The output voltage of 105 is fed back and a control voltage is output according to its magnitude.

The band pass filter 107 passes only the frequency of the desired band among the first IF frequencies output from the first mixer 104, and the second amplifier 108 is connected to the output terminal of the band pass filter 107 and therefrom. Amplifying the output signal, the second mixer 109 mixes the first IF frequency signal amplified by the second amplifier 108 and the oscillation frequency input from the second local oscillator 110, the secondary IF frequency of 45MHz The second local oscillator 110 generates a predetermined oscillation frequency according to the control voltage of the second PLL 111 and outputs it to the second mixer 109 when the channel is tuned, and the second PLL 111 The output voltage of the second local oscillator 110 is fed back and a control voltage is output to the second local oscillator 110 according to its magnitude.

The second switch 116 has a movable contact connected to an output terminal of the second mixer 109, a fixed contact connected to an input terminal of the second low pass filter 117, and an input terminal of the third low pass filter 118. B fixed contact is connected to and supplies a second IF frequency output from the second mixer 109 to the second low pass filter 117 or the third low pass filter 118 by switching according to an external control signal. . Here, the second switch 116 is switched under the control of the QAM or QPSK of the system.

The second low pass filter 117 passes only the frequency of the 10 MHz band of the secondary IF frequencies output from the second switch 116, and the third low pass filter 118 outputs 2 output from the second switch 116. Pass only frequencies in the 10-45MHz band of the difference IF frequencies.

Hereinafter, the operation of the terrestrial and satellite broadcasting combination tuner according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

First, when a broadcast signal for terrestrial wave is to be received, each movable contact of the first switch 115 and the second switch 116 is connected to a fixed contact in QAM or QPSK of the system. At this time, the movable contact of the first switch 115 and the second switch 116 may maintain a state connected to the a fixed contact in the initial state.

Then, the high frequency signal introduced through the first antenna ANT 1 passes through the AGC 101, the first amplifier 102, and the first low pass filter 103 through the first switch 115 to be in a tuned waveform. Which is upconverted to the first order IF frequency (1038 MHz) while passing through the first mixer 104 and the desired band of the first order IF frequencies output from the first mixer 104 by the band pass filter 107. Only the frequency of is passed.

The signal is amplified while passing through the second amplifier 108, down-converted to the IF frequency (45 MHz) while passing through the second mixer 109, and then, through the second switch 116, the second low pass filter ( 117) only the frequency in the 10 MHz band is passed.

On the contrary, if the broadcast signal for the satellite wave is to be received, the movable contact of the first switch 115 and the second switch 116 is connected to the b fixed contact in the QAM or QPSK of the system.

Then, the high frequency signal introduced through the second antenna ANT 2 passes through the third mixer 112, and the high frequency signal is canceled. Only the signal of 479.5 MHz provides the movable contact and the b fixed contact of the first switch 115. Through AGC 101.

The signal is amplified while passing through the second amplifier 108, down-converted to the IF frequency (45 MHz) while passing through the second mixer 109, and then, through the second switch 116, a third low pass filter ( Only the frequencies in the 10-45MHz band are passed through 117).

Therefore, by adding a plurality of switches to one tuner, the terrestrial and satellite signals input through the respective antennas are selectively introduced into the circuit through the switching of the switches, and the primary IF signals output from the first mixer are different from each other. Passing a pass filter, the second mixer can downconvert this signal to 45 MHz to receive both terrestrial and satellite waves.

<Second Embodiment>

Hereinafter, the configuration of a terrestrial and satellite broadcasting combination tuner according to another embodiment of the present invention will be described in detail with reference to FIG. 3.

3 is a block diagram showing the configuration of a terrestrial and satellite broadcasting combination tuner according to another embodiment of the present invention.

Referring to FIG. 3, the terrestrial and satellite broadcasting combination tuner 200 according to the present invention includes a tenth antenna ANT 1, an AGC 201, a tenth amplifier 202, and a tenth low pass filter ( 203, 10th mixer 204, 10th local oscillator 205, 10th PLL 206, band pass filter 207, 20th amplifier 208, 20th mixer 209 ), 20th local oscillator 210, 20th PLL 211, 20th antenna ANT 2, 30th mixer 212, 30th local oscillator 213, 30th PLL ( 214, the tenth switch 215, the twentieth switch 216, the twentieth low pass filter 217, and the thirtieth low pass filter 218.

The tenth antenna (ANT 1) receives terrestrial waves in the 44 ~ 860MHz band.

The AGC 201 automatically adjusts the gain of the video signal at all times even when the magnitude of the high frequency signal input through the tenth antenna ANT 1 changes, and the tenth amplifier 202 passes through the AGC 201. The high frequency signal is amplified, and the tenth low pass filter 203 passes only a high frequency signal of 860 MHz or less among the high frequency signals amplified by the tenth amplifier 202.

The tenth mixer 204 mixes the high frequency signal selected by the tenth low pass filter 203 and the oscillation frequency input from the tenth local oscillator 205, upconverts to the first IF frequency of 1038 MHz, and outputs the tenth mixer. The local oscillator 205 generates a predetermined oscillation frequency according to the control voltage supplied from the tenth PLL 206 and outputs it to the tenth mixer 204 when the channel is tuned, and the tenth PLL 206 is the tenth local oscillator. The output voltage of 205 is fed back and a control voltage is output according to its magnitude.

The band pass filter 207 passes only a frequency of a desired band among the first IF frequencies output from the tenth mixer 204, and the twentieth amplifier 208 is connected to an output terminal of the band pass filter 207 and therefrom. Amplifying the output signal, the twentieth mixer 209 mixes the first IF frequency signal amplified by the twentieth amplifier 208 and the oscillation frequency input from the twentieth local oscillator 210 to the second IF frequency of 45 MHz. The 20th local oscillator 210 generates a predetermined oscillation frequency according to the control voltage of the 20th PLL 211 and outputs it to the 20th mixer 209 when the channel is tuned, and the 20th PLL 211 The output voltage of the second local oscillator 210 is fed back and a control voltage is output to the twentieth local oscillator 210 according to its magnitude.

The second antenna ANT 2 receives satellite waves of 950-2150 MHz.

The thirtieth mixer 212 mixes the high frequency signal input through the twentieth antenna ANT 2 and the oscillation frequency input from the thirtieth local oscillator 213 and outputs a high frequency signal of 479.5 MHz.

The thirtieth local oscillator 213 generates an oscillation frequency obtained by adding a high frequency signal and 479.5 MHz according to the control voltage input from the thirtieth PLL 214, and outputs the oscillation frequency to the thirtieth mixer 212. In response to the voltage of the thirtieth local oscillator 213, the control voltage is output to the thirtieth local oscillator 213.

In the tenth switch 215, a fixed contact is connected to the output terminal of the twentieth mixer 209, b fixed contact is connected to the output terminal of the thirtieth mixer 212, and the movable contact is controlled by a control signal input from the outside. A second IF frequency output from the 20th mixer 209 or an IF frequency output from the 30th mixer 212 is selectively output to the 20th switch 216. Here, the tenth switch 215 is switched under the control of the QAM or QPSK of the system, and the movable contact is changed in conjunction with the twentieth switch 216.

In the twentieth switch 216, a fixed contact is connected to the movable contact of the tenth switch 215, a fixed contact is connected to an input terminal of the twentieth low pass filter 217, and the thirtieth low pass filter 218 The b fixed contact is connected to an input terminal of and a second IF frequency output from the twentieth mixer 209 or the second IF frequency output from the thirtieth mixer 212 is switched according to an external control signal. 217 or the thirtieth low pass filter 218. Here, the twentieth switch 216 is switched under the control of the QAM or QPSK of the system.

The second low pass filter 117 passes only the frequency of the 10 MHz band of the secondary IF frequencies output from the second switch 116, and the third low pass filter 118 outputs 2 output from the second switch 116. Pass only frequencies in the 10-45MHz band of the difference IF frequencies.

Hereinafter, the operation of the terrestrial and satellite broadcasting combination tuner according to another embodiment of the present invention will be described in detail with reference to FIG. 3.

First, when a broadcast signal for terrestrial wave is to be received, each movable contact of the tenth switch 215 and the twentieth switch 216 is connected to a fixed contact in QAM or QPSK of the system. In this case, the movable contact of the tenth switch 215 and the twentieth switch 216 may maintain a state in which it is connected to the a fixed contact as an initial state.

Then, the high frequency signal introduced through the first antenna ANT 1 is made into a tuning waveform while passing through the AGC 201, the tenth amplifier 202, and the tenth low pass filter 203, which is a tenth mixer ( Up-converting to the primary IF frequency (1038 MHz) while passing through 204, only the frequency of the desired band of the primary IF frequencies output from the tenth mixer 204 by the band pass filter 207 is passed.

The signal is amplified while passing through the twentieth amplifier 208, down-converted to the IF frequency (45 MHz) while passing through the twentieth mixer 209, and then the tenth switch 215 and the twentieth switch 216 are turned off. Only the frequency of the 10MHz band is passed through the twentieth low pass filter 217.

On the contrary, if the broadcast signal for the satellite wave is to be received, the movable contact of the tenth switch 215 and the twentieth switch 216 is connected to the b fixed contact in the QAM or QPSK of the system.

Then, the high frequency signal introduced through the twentieth antenna ANT 2 cancels the high frequency signal while passing through the thirtieth mixer 212, and only a signal of 479.5 MHz provides the movable contact and the b fixed contact of the tenth switch 215. Through the 20 th switch 216 is output.

As a result, the IF signal passing through the twentieth 216 is passed by only the frequency of the 10 ~ 45MHz band by the thirtieth low pass filter 217.

Therefore, by adding a plurality of switches to one tuner, the terrestrial and satellite signals input through the respective antennas are selectively introduced into the circuit through the switching of the switches, and the second IF frequency or the thirtieth mixer output from the 20th mixer is output. By passing the IF frequencies output from different low pass filters, both terrestrial and satellite waves can be received.

As described above, according to the combination tuner for terrestrial and satellite broadcasting according to the present invention, it is possible to receive terrestrial and satellite waves with one tuner, thereby reducing the manufacturing cost and volume of the product.

Claims (14)

The first antenna, the AGC, the first amplifier, the first low pass filter, the first mixer, the first local oscillator, the first PLL, the band pass filter, the second amplifier, and the second mixer A double conversion tuner comprising a second local oscillator and a second PLL, A satellite frequency output unit for receiving a satellite wave and outputting a predetermined frequency; First switching means for selectively outputting a high frequency signal input from the first antenna or a high frequency signal output from the satellite frequency output unit to the AGC by being switched by a control signal input from the outside; Second switching means for selectively supplying a second IF frequency which is switched according to an external control signal and output from the second mixer; A second low pass filter for passing only a frequency in a 10 MHz band of the second IF frequencies output from the second switching means; And a third low pass filter configured to pass only a frequency in a 10 to 45 MHz band among the secondary IF frequencies output from the second switching means. The method of claim 1, The satellite frequency output unit, A second antenna for receiving satellite waves, A third mixer for mixing a high frequency signal input through the second antenna and an oscillation frequency input from the outside to output a predetermined frequency; A third local oscillator for generating a predetermined oscillation frequency according to a control voltage input from the outside and outputting the oscillation frequency to the third mixer; And a third PLL configured to output a control voltage to the third local oscillator. The method of claim 2, The third local oscillator, And a combination tuner for terrestrial and satellite broadcasting, comprising generating an oscillation frequency by adding a signal of 479.5 MHz to a high frequency signal flowing through the second antenna. The method of claim 1, The first low pass filter, A combination tuner for terrestrial and satellite broadcasting, which passes only high frequency signals of 860 MHz or less. The method according to claim 1 or 2, The first switching means, One fixed contact is connected to the output terminal of the first antenna, the other fixed contact is connected to the output terminal of the third mixer of the satellite frequency output unit, and is connected to the AGC by a control signal input from the outside. Combination tuner for terrestrial and satellite broadcasting, characterized in that the contacts are switched. The method of claim 1, The second switching means, A movable contact is connected to an output terminal of the second mixer, one fixed contact is connected to the second low pass filter, and another fixed contact is connected to the third low pass filter, thereby providing an external control signal. And a second IF frequency switched from the second mixer and selectively supplied to the second low pass filter or the third low pass filter. The method of claim 1, The first switching means and the second switching means, Combination tuner for terrestrial and satellite broadcasting, which is switched under the control of the system's QAM or QPSK. The first antenna, the AGC, the first amplifier, the first low pass filter, the first mixer, the first local oscillator, the first PLL, the band pass filter, the second amplifier, and the second mixer A double conversion tuner comprising a second local oscillator and a second PLL, A satellite frequency output unit for receiving a satellite wave and outputting a predetermined frequency; First switching means for selectively outputting a second IF frequency input from the second mixer or a high frequency signal output from the satellite frequency output unit by a control signal input from the outside; Second switching means for selectively supplying a second IF frequency which is switched according to an external control signal and output from the first switching means, A second low pass filter for passing only a frequency in a 10 MHz band of the second IF frequencies output from the second switching means; And a third low pass filter configured to pass only a frequency in a 10 to 45 MHz band among the secondary IF frequencies output from the second switching means. The method of claim 8, The satellite frequency output unit, A second antenna for receiving satellite waves, A third mixer for mixing a high frequency signal input through the second antenna and an oscillation frequency input from the outside to output a predetermined frequency; A third local oscillator for generating a predetermined oscillation frequency according to a control voltage input from the outside and outputting the oscillation frequency to the third mixer; And a third PLL configured to output a control voltage to the third local oscillator. The method of claim 9, The third local oscillator, And a combination tuner for terrestrial and satellite broadcasting, comprising generating an oscillation frequency by adding a signal of 479.5 MHz to a high frequency signal flowing through the second antenna. The method of claim 8, The first low pass filter, A combination tuner for terrestrial and satellite broadcasting, which passes only high frequency signals of 860 MHz or less. The method according to claim 8 or 9, The first switching means, A movable contact is connected to an output terminal of the second mixer, one fixed contact is connected to an output terminal of the third mixer of the satellite frequency output unit, and another fixed contact is connected to an input terminal of the second switching means. Combination tuner for terrestrial and satellite broadcasting, characterized in that. The method of claim 8, The second switching means, A movable contact is connected to one fixed contact of the first switching means, any one fixed contact is connected to the second low pass filter, and another fixed contact is connected to the third low pass filter, And a tertiary IF frequency, which is switched according to an external control signal and selectively supplied to the second low pass filter or the third low pass filter, to output a second IF frequency output from the second mixer. The method of claim 8, The first switching means and the second switching means, Combination tuner for terrestrial and satellite broadcasting, which is switched under the control of the system's QAM or QPSK.