Low Noise Amplifier Control with Two Tuners

专利摘要:
A low noise amplifier controller is disclosed when using two tuners in accordance with the present invention. The configuration of the apparatus includes a low noise amplifier for selectively amplifying a broadcast signal introduced from an antenna in response to a control signal applied thereto, a first tuner for tuning a predetermined channel from a broadcast signal output from the low noise amplifier, and in the low noise amplifier A second tuner that tunes another channel from the output broadcast signal; and a first intermediate outputting the first AGC on signal when the level of the broadcast signal of the predetermined channel output from the first tuner is less than the reference level. A second intermediate frequency amplifier circuit for outputting a second AGC on signal when the level of the broadcast signal of another channel output from the second tuner is less than the reference level, when the frequency amplifier circuit is smaller than the reference level; And a comparison unit configured to provide a control signal for determining whether to operate the low noise amplifier 102 based on the second AGC on signal. Therefore, as described above, according to the present invention, when the signal gain between the two channels is large, amplifying a channel having a large signal gain has an effect of preventing the low noise amplifier from operating when it is saturated.
公开号:KR19980057718A
申请号:KR1019960077017
申请日:1996-12-30
公开日:1998-09-25
发明作者:오지병
申请人:김광호；삼성전자 주식회사；
IPC主号:

专利说明:

Low Noise Amplifier Control with Two Tuners
The present invention relates to a low noise amplifier control device. More specifically, the comparison unit controls the operation of a low noise amplifier by using a comparison signal obtained by subtracting two channel signals from a reference signal so as not to saturate a channel having a large signal gain. A low noise amplifier control when using two tuners.
Nowadays, many TVs using two tuners, such as widescreen TVs or Picture in Picture TVs, are commercially available. For TVs using these two tuners, when the signal gain passed through the low noise amplifier and through the tuner and the intermediate amplifier circuit is less than the reference signal gain, it will be a matter of which signal to operate the low noise amplifier based on. Can be.
1 is a block diagram of a low noise amplifier control device using two conventional tuners.
In Fig. 1, reference numeral 102 denotes a low noise amplifier, 104 denotes a first tuner, 106 denotes a second tuner, 108 denotes a first intermediate frequency amplifier circuit, 110 denotes a second intermediate frequency amplifier circuit, and 112 denotes a microcomputer. Respectively.
Next, the operation of the apparatus shown in FIG. 1 will be described.
The low noise amplifier 102 selectively amplifies the broadcast signal introduced from the antenna in response to a control signal applied thereto. The low noise amplifier 102 is an amplifier designed to amplify a signal but reduce noise generated. To reduce noise, the low noise amplifier 102 pays attention to component selection and uses a low noise transistor. The first tuner 104 tunes one channel (eg, MBC) among the signals amplified by the low noise amplifier 102. The second tuner 106 tunes one other channel (eg, SBS) among the signals amplified by the low noise amplifier 102. The first intermediate frequency amplifier circuit 108 and the second intermediate frequency amplifier circuit 110 amplify signals output from the first tuner 104 and the second tuner 106 to output AGC (Automatic Gain Control) voltages. . The microcomputer 112 feeds back to the low noise amplifier 102 to amplify the AGC voltage again when the AGC voltage output from the first intermediate frequency amplifier circuit is equal to or lower than a predetermined voltage (a constant sensitivity gain of the input signal). In FIG. 1, while the microcomputer 112 feeds back the AGC voltage output from the first intermediate frequency amplifier circuit 108 to the low noise amplifier 102, the microcomputer 112 outputs the AGC voltage output from the second intermediate frequency amplifier circuit 110 to the low noise amplifier ( 102 may also be fed back. That is, when using two conventional tuners, the low noise amplifier control device detects the AGC voltage output from any one of the intermediate frequency amplifier circuits and feeds it back to the low noise amplifier 102.
When using the conventional two tuners, the low noise amplifier controller operates the low noise amplifier based on any one channel signal. Therefore, when the signal sensitivity difference between the two channels is large, the low noise amplifier is operated based on the poor signal sensitivity channel. In this case, a channel with good signal sensitivity becomes saturation, and thus the screen state becomes worse.
The present invention has been made to solve the above-mentioned problems, and the comparison unit controls the operation of the low noise amplifier using a comparison signal obtained by subtracting two channel signals from the reference signal so that the channel with a large signal gain is not saturated. It is an object to provide a low noise amplifier control when using two tuners.
1 is a block diagram of a low noise amplifier control device using two conventional tuners.
2 is a block diagram of a low noise amplifier controller when using two tuners according to the present invention.
A low noise amplifier control apparatus using two tuners according to the present invention for achieving the above object comprises: a low noise amplifier for selectively amplifying a broadcast signal introduced from an antenna in response to a control signal applied thereto; A first tuner that tunes a predetermined channel from the broadcast signal output from the low noise amplifier; A second tuner that tunes to another channel from the broadcast signal output from the low noise amplifier; A first intermediate frequency amplifier circuit for comparing the level of the broadcast signal of the predetermined channel output from the first tuner with a reference level and outputting a first AGC on signal when the level is less than the reference level; A second intermediate frequency amplifier circuit for outputting a second AGC on signal when the level of the broadcast signal of another channel output from the second tuner is compared with a reference level and less than the reference level; It is preferable to include a comparison unit for providing a control signal for determining whether to operate the low noise amplifier 102 based on the first AGC on and the second AGC on signal.
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
2 is a block diagram of a low noise amplifier controller when using two tuners according to the present invention.
The configuration of the apparatus shown in FIG. 2 selects a predetermined channel from the broadcast signal output from the low noise amplifier 102 and the low noise amplifier 102 to selectively amplify the broadcast signal introduced from the antenna in response to a control signal applied thereto. The level of the broadcast signal of the predetermined channel output from the first tuner 104, the second tuner 106 to tune to another channel from the broadcast signal output from the low noise amplifier 102, and the first tuner 104 Compared with the reference level, the level of the broadcast signal of another channel output from the first intermediate frequency amplifier circuit 108 and the second tuner 106 that outputs the first AGC on signal when the reference level is less than the reference level is compared with the reference level. The first AGC on and the second AGC on output from the second intermediate frequency amplifier circuit 108, the first intermediate frequency amplifier circuit 108, and the second intermediate frequency amplifier circuit 108 outputting a second AGC on signal when the level is less than the level. Low noise based on signal It comprises a comparison unit 22 for providing a control signal for determining whether to operate the amplifier 102.
Next, the operation of the apparatus shown in FIG. 2 will be described.
The low noise amplifier 102 selectively amplifies the broadcast signal introduced from the antenna in response to a control signal applied thereto. The first tuner 104 selects a predetermined channel from the broadcast signal output from the low noise amplifier 102. The second tuner 106 selects another channel from the broadcast signal output from the low noise amplifier 102. The first intermediate frequency amplifier circuit 108 compares a level of a broadcast signal of a predetermined channel output from the first tuner 104 with a reference level, and outputs a first AGC on signal when it is less than the reference level. The second intermediate frequency amplifier circuit 108 compares the level of the broadcast signal of the other channel output from the second tuner 106 with the reference level, and outputs the second AGC on signal when it is less than the reference level. The comparison unit 22 determines whether to operate the low noise amplifier 102 based on the first AGC on and second AGC on signals output from the first intermediate frequency amplifier circuit 108 and the second intermediate frequency amplifier circuit 108. Provide control signals.
For example, it is assumed that the signal amplifier amplification ratio is 20 dB and the signal amplification control reference gain is 60 dB. At this time, if the first tuner 104 signal gain is 50dB and the second tuner signal gain is 90dB, the first tuner 104 signal gain (50dB) is smaller than the signal amplification control reference gain (60dB), but at this time, the first intermediate The amplifying circuit outputs the first AGC on signal.) When the second tuner gain (90 dB) is amplified, the amplifier is saturated (110 dB; the second intermediate amplifier circuit does not output the second AGC on signal). ) Does not operate the low noise amplifier 102.
On the other hand, if the first tuner 104 signal gain is 50 dB and the second tuner 106 signal gain is 70 dB, the first tuner 104 signal gain (50 dB; first AGC on) and the second tuner 106 signal gain ( 70dB; the second AGC on) does not saturate even when the amplification is performed, so that the comparator 22 operates the low noise amplifier 102.
Also, if both the first tuner 104 signal gain and the second tuner 106 signal gain are equal to or less than the signal amplification control reference gain (first AGC on and second AGC on), the comparing unit 22 causes the low noise amplifier 102 to operate. do.
In the case where the low noise amplifier 102 is operated as a result, both the first tuner 104 signal gain and the second tuner 106 signal gain are equal to or less than the signal amplification control reference gain (first AGC on and second AGC on), or This is when either one of the tuner 104 signal gain and the second tuner 106 signal gain is equal to or less than the signal amplification control reference gain and at the same time does not saturate the other gain.
In FIG. 2, when using both tuners (when watching two channel signals on the screen, watching one channel and using another channel for recording in TVCR, etc.), the comparing unit 22 Both tuner signal gains are compared to control the low noise amplifier 102. In case of using only one tuner (when recording using only one tuner, watching only one channel, etc.), the comparing unit 22 controls the low noise amplifier 102 based only on the tuner signal gain. .
As described above, according to the present invention, when the signal gain between the two channels is large, amplifying a channel having a large signal gain has an effect of preventing the low noise amplifier from operating when it is saturated.

权利要求:
Claims (4)
[1" claim-type="Currently amended] A low noise amplifier for selectively amplifying the broadcast signal introduced from the antenna in response to a control signal applied thereto;
A first tuner that tunes a predetermined channel from the broadcast signal output from the low noise amplifier;
A second tuner that tunes to another channel from the broadcast signal output from the low noise amplifier;
A first intermediate frequency amplifier circuit for comparing the level of the broadcast signal of the predetermined channel output from the first tuner with a reference level and outputting a first AGC on signal when the level is less than the reference level;
A second intermediate frequency amplifier circuit for outputting a second AGC on signal when the level of the broadcast signal of another channel output from the second tuner is compared with a reference level and less than the reference level;
And a comparator for providing a control signal for determining whether to operate the low noise amplifier (102) based on the first AGC on signal and the second AGC on signal.
[2" claim-type="Currently amended] The method of claim 1, wherein the comparison unit
And outputting a control signal for operating the low noise amplifier when both the first AGC on signal and the second AGC on signal are output from the first and second intermediate frequency amplifier circuits. Device.
[3" claim-type="Currently amended] The method of claim 1, wherein the comparison unit
Control for operating the low noise amplifier when one of the first AGC on signal and the second AGC on signal is output from the first and second intermediate frequency amplifier circuits and the signal is not saturated even when the other signal gain is amplified. Low noise amplifier control device using two tuners, characterized in that to output a signal.
[4" claim-type="Currently amended] The method of claim 1, wherein the comparison unit
When both the first tuner and the second tuner are used, the operation of the low noise amplifier is determined by comparing both the first tuner signal gain and the second tuner signal gain, and only one of the first tuner and the second tuner is determined. In the case of using the low-noise amplifier control device, characterized in that for determining the low noise amplifier operation based on the tuner signal gain used only.

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同族专利:

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公开号 | 公开日

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KR100207711B1|1999-07-15|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
1996-12-30|Application filed by 김광호, 삼성전자 주식회사

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1996-12-30|Priority to KR1019960077017A

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1998-09-25|Publication of KR19980057718A

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1999-07-15|Application granted

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1999-07-15|Publication of KR100207711B1

优先权:

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申请号 | 申请日 | 专利标题

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KR1019960077017A|KR100207711B1|1996-12-30|1996-12-30|Apparatus for controlling low noise amplifier in using 2 tuners|