KR0163857B1 - Tuner for satellite broadcasting receiver - Google Patents

Tuner for satellite broadcasting receiver Download PDF

Info

Publication number
KR0163857B1
KR0163857B1 KR1019960030324A KR19960030324A KR0163857B1 KR 0163857 B1 KR0163857 B1 KR 0163857B1 KR 1019960030324 A KR1019960030324 A KR 1019960030324A KR 19960030324 A KR19960030324 A KR 19960030324A KR 0163857 B1 KR0163857 B1 KR 0163857B1
Authority
KR
South Korea
Prior art keywords
gain control
control amplifier
amplification degree
output
signal
Prior art date
Application number
KR1019960030324A
Other languages
Korean (ko)
Other versions
KR980012871A (en
Inventor
우제동
Original Assignee
조희재
엘지전자부품주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 조희재, 엘지전자부품주식회사 filed Critical 조희재
Priority to KR1019960030324A priority Critical patent/KR0163857B1/en
Publication of KR980012871A publication Critical patent/KR980012871A/en
Application granted granted Critical
Publication of KR0163857B1 publication Critical patent/KR0163857B1/en

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/06—Arrangements for obtaining constant bandwidth or gain throughout tuning range or ranges
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/4446—IF amplifier circuits specially adapted for B&W TV
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/50—Tuning indicators; Automatic tuning control

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Circuits Of Receivers In General (AREA)

Abstract

본 발명은 고주파이득제어증폭기의 증폭도를 제어하여 일정한 세기의 IF신호가 복조회로에 출력되는 위성방송수신용 튜너에 관한 것으로서, 수신된 위성방송신호중 불필요한 신호를 제거하는 입력필터와, 상기 입력필터에서 출력된 위성방송신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 고주파이득제어증폭기와, 상기 고주파이득제어증폭기에서 출력된 위성방송신호와 국부발진기에서 출력된 국부발진신호를 혼합하는 혼합기와, 상기 혼합기에서 출력된 신호중 IF대역만 통과시키는 IF대역통과필터와, 상기 IF대역통과필터에서 출력된 IF신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 IF이득제어증폭기와, 상기 IF이득제어증폭기에서 출력된 IF신호를 받아 상기 고주파이득제어증폭기와 중간주파수 이득제어증폭기의 증폭도를 제어하는 증폭도제어회로로 구성된 것을 본 발명의 요지로 한다.The present invention relates to a satellite broadcast tuner in which an IF signal having a constant intensity is output to a demodulation circuit by controlling an amplification degree of a high frequency gain control amplifier. An input filter for removing unnecessary signals from the received satellite broadcast signals, and the input filter. A high frequency gain control amplifier for amplifying the satellite broadcast signal outputted from the receiver according to an appropriate amplification degree, a mixer for mixing the satellite broadcast signal output from the high frequency gain control amplifier and the local oscillation signal output from the local oscillator, and the mixer An IF bandpass filter for passing only IF band among the signals output from the IF bandpass filter, an IF gain control amplifier for amplifying the IF signal output from the IF bandpass filter to a predetermined amplitude according to an appropriate amplification degree, and an IF output amplifier from the IF gain control amplifier. Receives a signal to control the amplification degree of the high frequency gain control amplifier and the intermediate frequency gain control amplifier. And the amplification degree control circuit consisting of a substance of the present invention.

Description

위성방송 수신용 튜너Satellite tuner

제1도는 종래의 위성방송 수신용 튜너의 블럭도.1 is a block diagram of a conventional satellite broadcast tuner.

제2도는 본 발명에 의한 위성방송 수신용 튜너의 블럭도.2 is a block diagram of a tuner for satellite broadcast reception according to the present invention.

제3도는 제2도의 증폭도제어회로를 나타낸 상세회로도.3 is a detailed circuit diagram showing the amplification degree control circuit of FIG.

* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings

1 : 입력필터 2 : 고주파이득제어증폭기1: input filter 2: high frequency gain control amplifier

3 : 혼합기 4 : 국부발진기3: mixer 4: local oscillator

5 : IF대역통과필터 10 : IF직류변환회로5: IF band pass filter 10: IF DC conversion circuit

20 : 비교기 22 : 연산증폭기20: comparator 22: operational amplifier

30 : 저역통과필터 40 : IF이득제어증폭기30: low pass filter 40: IF gain control amplifier

100 : 증폭도제어회로 D1, D2 : 쇼트키베리어다이오드100: amplification degree control circuit D1, D2: Schottky barrier diode

R1, R2 : 저항 C1, C2 : 커패시터R1, R2: resistors C1, C2: capacitors

본 발명은 위성방송 수신용 튜너에 관한 것으로서, 특히 고주파이득제어증폭기의 증폭도를 제어하여 일정한 세기의 중간주파수(이하는 IF 라 칭함)신호가 복조회로에 출력되는 위성방송수신용 튜너에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuner for satellite broadcast reception, and more particularly to a tuner for satellite broadcast reception in which an intermediate frequency (hereinafter referred to as IF) signal of constant intensity is output to a demodulation circuit by controlling the amplification degree of a high frequency gain control amplifier. .

일반적으로 튜너에 수신된 위성방송신호는 IF단을 거쳐 IF신호로 변환되고 복조회로에서 복조된 후 베이스밴드출력단으로 출력되는바 수신된 위성방송신호는 주위환경에 따라 주파수가 일정하지 않기 때문에 복조된 IF신호에서 제어신호를 검출하여 IF단의 증폭기의 증폭도를 제어함으로서 일정한 크기의 IF신호가 베이스밴드출력단에 출력되어져 왔다.In general, the satellite broadcast signal received by the tuner is converted to the IF signal through the IF stage, demodulated by the demodulation circuit, and then output to the baseband output stage. The received satellite broadcast signal is demodulated because the frequency is not constant according to the surrounding environment. By detecting the control signal from the IF signal and controlling the amplification degree of the amplifier of the IF stage, the IF signal of a certain magnitude has been output to the baseband output stage.

이하 첨부도면을 참조하여 IF신호의 크기를 일정하게 유지하기 위한 증폭기의 증폭도가 제어되는 종래의 위성방송 수신용 튜너에 대해서 설명한다.Hereinafter, with reference to the accompanying drawings, a conventional satellite broadcasting tuner for controlling the amplification degree of an amplifier for maintaining a constant magnitude of an IF signal will be described.

종래의 위성방송 수신용 튜너의 블럭도가 도시된 제1도에서 보는 바와같이, 수신된 위성방송신호의 일정주파수대역만 통과시키는 입력필터(1)의 출력측에 연결되어 후술하는 복조회로(6)의 검출신호에 의해 일정레벨로 위성방송신호를 증폭하는 고주파이득제어증폭기(2)와 상기 고주파이득제어증폭기(2)의 출력신호와 국부발진기(4)에서 출력된 신호를 혼합하여 IF대역통과필터(5)를 통해 IF신호를 출력하는 혼합기(3)와 상기 IF대역통과필터(5)에서 출력된 IF신호를 복조하여 베이스밴드출력단(7)으로 출력함과 아울러 복조된 IF신호중 베이스밴드의 진폭에서 고주파이득제어증폭기(2)의 제어전압을 검출하고 이 검출신호를 상기 고주파이득제어증폭기(2)로 인가하는 복조회로(6)로 구성되어 있다.As shown in FIG. 1, which is a block diagram of a conventional satellite broadcasting tuner, a demodulation circuit 6 which is connected to an output side of an input filter 1 for passing only a predetermined frequency band of a received satellite broadcasting signal is described later. IF band pass by mixing the output signal of the high frequency gain control amplifier 2 and the output signal of the local oscillator 4 and the high frequency gain control amplifier 2 amplifying the satellite broadcast signal at a predetermined level by the detection signal of The demodulator 3 outputs the IF signal through the filter 5 and the IF signal output from the IF bandpass filter 5, and outputs the demodulated signal to the baseband output terminal 7. And a demodulation circuit 6 for detecting the control voltage of the high frequency gain control amplifier 2 in amplitude and applying the detected signal to the high frequency gain control amplifier 2.

따라서, 수신된 위성방송신호는 입력필터(1)를 통해 여과되고 고주파이득제어증폭기(2)에서 일정레벨로 증폭된 후 혼합기(3)로 출력된다.Therefore, the received satellite broadcast signal is filtered through the input filter 1, amplified to a predetermined level in the high frequency gain control amplifier 2, and then output to the mixer 3.

상기 혼합기(3)에 입력된 위성방송신호는 국부발진기(4)에서 출력된 국부발진신호와 혼합된 혼합신호로 바뀌어 IF대역통과필터(5)를 통해 선택적으로 여과되어 IF신호로 출력되고, 이 IF신호는 복조회로(6)에서 복조되어 베이스밴드출력단(7)으로 출력된다.The satellite broadcast signal input to the mixer 3 is converted into a mixed signal mixed with the local oscillation signal output from the local oscillator 4 and selectively filtered through an IF band pass filter 5 to be output as an IF signal. The IF signal is demodulated by the demodulation circuit 6 and output to the baseband output terminal 7.

이때 상기 복조기(6)에서는 복조된 IF신호중 베이스밴드의 진폭에 포함된 고주파이득제어증폭기(2)의 증폭도제어전압이 검출되고 이 검출신호가 상기 고주파이득제어증폭기(2)에 인가되어 증폭도가 제어된다.At this time, the demodulator 6 detects the amplification degree control voltage of the high frequency gain control amplifier 2 included in the amplitude of the baseband among the demodulated IF signals, and the detection signal is applied to the high frequency gain control amplifier 2 to control the amplification degree. do.

따라서 상기 고주파이득제어증폭기(2)에 입력된 위성방송신호는 적절한 증폭도에 의해 이득이 조절되고, 이로 인하여 일정한 크기로 제어된 IF신호가 복조회로(6)에 입력되게 되는 것이다.Therefore, the gain of the satellite broadcasting signal input to the high frequency gain control amplifier 2 is adjusted by the appropriate amplification degree, so that the IF signal controlled to a certain magnitude is input to the demodulation circuit 6.

그러나, 고주파이득제어증폭기(2)의 증폭도제어신호가 베이스밴드의 진폭에서 검출되어 정확한 IF신호의 세기를 검출하기가 불가능함으로 인하여 불안정한 크기의 IF신호가 복조회로(6)에 입력되는 문제점이 있었다.However, since the amplification degree control signal of the high frequency gain control amplifier 2 is detected at the amplitude of the baseband and thus it is impossible to detect the exact strength of the IF signal, an unstable size IF signal is input to the demodulation circuit 6. there was.

따라서, 본 고안은 상기 문제점을 해결하기 위하여 창출된 것으로서, 그 목적으로 하는 바는 복조회로에 입력되는 IF신호의 크기를 일정하게 유지할 수 있도록 고주파이득제어증폭기의 증폭도를 제어할 수 있는 위성방송 수신용 튜너를 제공하는데 있다.Therefore, the present invention was created to solve the above problems, and its purpose is to provide a satellite broadcasting capable of controlling the amplification degree of the high frequency gain control amplifier so that the magnitude of the IF signal input to the demodulation circuit can be kept constant. To provide a receive tuner.

이와같은 목적을 실현하기 위한 본 발명은 수신된 위성방송신호중 불필요한 신호를 제거하는 입력필터와, 상기 입력필터에서 출력된 위성방송신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 고주파이득제어증폭기와, 상기 고주파이득제어증폭기에서 출력된 위성방송신호와 국부발진기에서 출력된 국부발진신호를 혼합하는 혼합기와, 상기 혼합기에서 출력된 신호중 IF대역만 통과시키는 IF대역통과필터와, 상기 IF대역통과필터에서 출력된 IF신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 IF이득제어증폭기와, 상기 IF이득제어증폭기에서 출력된 IF신호를 받아 상기 고주파이득제어증폭기와 중간주파수이득제어증폭기의 증폭도를 제어하는 증폭도제어회로로 구성된 것을 특징으로 한다.The present invention for achieving the above object is an input filter for removing unnecessary signals of the received satellite broadcast signal, a high frequency gain control amplifier for amplifying the satellite broadcast signal output from the input filter to a predetermined size according to an appropriate amplification degree, A mixer for mixing the satellite broadcasting signal output from the high frequency gain control amplifier and the local oscillation signal output from the local oscillator, an IF bandpass filter for passing only the IF band among the signals output from the mixer, and an output of the IF bandpass filter. An IF gain control amplifier for amplifying an IF signal to a predetermined magnitude according to an appropriate amplification degree, and an amplification degree control circuit for controlling the amplification degree of the high frequency gain control amplifier and the intermediate frequency gain control amplifier by receiving an IF signal output from the IF gain control amplifier. Characterized in that configured.

이하 첨부도면을 참조하여 본 발명에 의한 위성방송 수신용 튜너를 자세하게 설명한다.Hereinafter, a tuner for satellite broadcast reception according to the present invention will be described in detail with reference to the accompanying drawings.

제2도는 본 발명에 의한 위성방송 수신용 튜너의 블록도이다.2 is a block diagram of a tuner for satellite broadcast reception according to the present invention.

도면중 부호 10은 IF직류변환회로, 20은 비교기, 30은 저역통과필터, 100은 증폭도제어회로를 나타낸다.In the figure, reference numeral 10 denotes an IF DC conversion circuit, 20 a comparator, 30 a low pass filter, and 100 an amplification degree control circuit.

제2도를 참조하면, 본 발명에 의한 위성방송 수신용 튜너는 수신된 위성방송신호를 여과하는 입력필터(1)의 출력단에 연결되어 여과된 위성방송신호를 후술하는 증폭도제어회로(100)의 제어신호에 의해 결정된 증폭도에 따라 증폭하는 고주파이득제어증폭기(2)와, 상기 고주파이득제어증폭기(2)에서 출력된 위성방송신호와 국부발진기(4)에서 출력된 국부발진신호를 혼합하는 혼합기(3)와, 상기 혼합기(3)에서 출력된 신호를 받아 IF대역만 통과시키는 IF대역통과필터(5)와, 상기 IF대역통과필터(5)를 통해 인가된 증폭도제어회로(100)의 제어신호에 의해 결정된 증폭도에 따라 상기 IF대역통과필터(5)에서 입력된 IF신호를 일정한 크기로 증폭하여 후단의 복조회로(도면에 도시되지 않음)에 출력하는 IF이득제어증폭기(40)와, 상기 IF이득제어증폭기(40)의 출력단에 연결되어 증폭도를 제어하는 제어신호를 상기 고주파이득제어증폭기(2) 및 IF대역통과필터(5)에 출력하는 IF직류변환회로(10), 비교기(20) 및 저역통과필터(30)로 이루어진 증폭도제어회로(100)로 구성된다.Referring to FIG. 2, the tuner for receiving a satellite broadcast according to the present invention is connected to an output terminal of the input filter 1 for filtering the received satellite broadcast signal, so as to describe the filtered satellite broadcast signal. A mixer for mixing a high frequency gain control amplifier 2 for amplifying according to an amplification degree determined by a control signal, and a satellite broadcasting signal output from the high frequency gain control amplifier 2 and a local oscillation signal output from the local oscillator 4 ( 3), an IF band pass filter 5 for receiving the signal output from the mixer 3 and passing only the IF band, and a control signal of the amplification degree control circuit 100 applied through the IF band pass filter 5. An IF gain control amplifier 40 for amplifying the IF signal inputted from the IF bandpass filter 5 to a predetermined magnitude according to the amplification degree determined by and outputting the amplified circuit to a subsequent demodulation circuit (not shown); Output stage of IF gain control amplifier 40 An amplification degree composed of an IF direct current conversion circuit 10, a comparator 20 and a low pass filter 30 which are connected and output a control signal for controlling the amplification degree to the high frequency gain control amplifier 2 and the IF band pass filter 5. It consists of a control circuit 100.

상기 증폭도제어회로(100)는 제3도에서 보는 바와같이 IF이득제어증폭기(40)에서 출력된 교류인 IF신호를 받는 애노드가 접지된 쇼트키베리어다이오드(D1)와 이 쇼트키베리어다이오드(D1)의 캐소드에 애노드가 연결된 쇼트키베리어다이오드(D2)와 상기 쇼트키베리어다이오드(D2)의 캐소드에서 접지된 커패시터(C1) 및 직렬연결된 저항(R1)으로 구성되어 정류작용을 하는 IF직류변환회로(10)와, 한 입력단에 인가된 상기 IF직류변환회로(10)에서 출력된 직류신호를 다른 입력단에 인가된 기준값과 비교하여 그 차신호를 출력하는 연산증폭기(22)로 구성된 비교기(20)와, 상기 비교기(20)에서 출력된 신호를 받아 고역의 신호를 제거하는 병렬 연결된 저항(R2), 콘덴서(C2)로 구성된 저역통과필터(30)로 이루어져 있다.As shown in FIG. 3, the amplification control circuit 100 includes a schottky barrier diode D1 and an schottky barrier diode D1 grounded with an anode receiving an IF signal, which is an AC output from the IF gain control amplifier 40. IF DC conversion circuit consisting of a Schottky barrier diode (D2) connected to the anode of the cathode) and a capacitor (C1) and a series connected resistor (R1) grounded at the cathode of the Schottky barrier diode (D2). A comparator 20 composed of an operational amplifier 22 for comparing the DC signal output from the IF DC conversion circuit 10 applied to one input terminal with a reference value applied to the other input terminal and outputting the difference signal; And a low pass filter 30 composed of a resistor R2 and a capacitor C2 connected in parallel to receive a signal output from the comparator 20 and to remove a high frequency signal.

이하 본 고안에 의한 위성방송 수신용 튜너의 작용 및 효과를 설명한다.Hereinafter, the operation and effects of the tuner for satellite broadcast reception according to the present invention will be described.

수신된 위성방송신호는 입력필터(1)를 통과하면서 불필요한 신호가 제거된 채 고주파이득제어증폭기(2)에 들어가게 되는데 이때 증폭도제어회로(100)에서 출력된 제어신호에 의해 제어된 증폭도에 의해 일정한 크기로 증폭되게 된다.The received satellite broadcast signal enters the high frequency gain control amplifier 2 while removing unnecessary signals while passing through the input filter 1, whereby the amplification degree controlled by the control signal output from the amplification control circuit 100 is constant. Will be amplified to size.

이후 증폭된 위성방송신호는 혼합기(3)에서 국부발진기(4)에서 출력된 국부발진신호와 혼합되고 IF대역통과필터(5)를 통과하면서 일정한 대역의 IF신호로 변환된다.The amplified satellite broadcast signal is then mixed with the local oscillation signal output from the local oscillator 4 in the mixer 3 and passed through the IF bandpass filter 5 to be converted into an IF signal of a constant band.

이때 증폭도제어회로(100)에서 출력된 제어신호가 상기 IF대역통과필터(5)에 인가되어 IF이득제어증폭기(40)로 출력된다.At this time, the control signal output from the amplification degree control circuit 100 is applied to the IF band pass filter 5 and output to the IF gain control amplifier 40.

따라서 IF이득제어증폭기(40)는 일정한 증폭도를 갖게되고 이 증폭도에 의해서 상기 IF대역통과필터(5)에서 출력된 IF신호는 일정한 크기로 증폭되어 복조기(도면에 도시되지 않음)로 출력된다.Therefore, the IF gain control amplifier 40 has a constant amplification degree, and by this amplification degree, the IF signal output from the IF bandpass filter 5 is amplified to a certain magnitude and output to a demodulator (not shown).

이때 증폭도제어회로(100)에서 제어신호의 생성과정은 다음과 같다.At this time, the process of generating the control signal in the amplification degree control circuit 100 is as follows.

IF이득제어증폭기(40)에서 출력된 IF신호는 교류로서 IF직류변환회로(100)에서 상호병렬로 연결된 쇼트키베리어 다이오드(D1),(D2)에 의해 직류성분으로 정류되고 콘덴서(C1) 및 저항(R1)을 통과하면서 평활하게 여파되어 비교기(20)의 연산증폭기(22)의 한 입력단에 인가된다.The IF signal output from the IF gain control amplifier 40 is an alternating current, rectified as a DC component by Schottky barrier diodes D1 and D2 connected in parallel with each other in the IF DC conversion circuit 100, and the capacitor C1 and The filter is smoothly filtered through the resistor R1 and applied to one input terminal of the operational amplifier 22 of the comparator 20.

상기 연산증폭기(22)의 한 입력단에 입력된 직류신호는 다른 입력단에서 입력된 기준값과 비교되고 두 신호의 차값이 저항(R2) 및 콘덴서(C2)로 구성된 저역통과필터(30)를 통과하면서 고역이 제거되어 고주파이득제어증폭기(2)와 IF이득제어증폭기(40)의 증폭도를 제어할 수 있는 제어신호로 변화된다.The DC signal input to one input terminal of the operational amplifier 22 is compared with the reference value input from the other input terminal, and the difference value of the two signals passes through the low pass filter 30 composed of the resistor R2 and the condenser C2. This is removed and changed into a control signal capable of controlling the amplification degree of the high frequency gain control amplifier 2 and the IF gain control amplifier 40.

상술한 구성 및 작용을 하는 본 발명에 의한 위성방송 수신용 튜너는 복조회로에 입력되는 교류인 IF신호를 직류로 변환하여 기준값과 비교한 후 저역통과필터를 통해 제어신호를 생성하는 증폭도제어회로에 의하여 고주파제어증폭기와 IF이득제어증폭기의 증폭도를 제어함으로서 일정한 크기의 IF가 복조회로에 입력되는 효과가 있다.The tuner for satellite broadcast reception according to the present invention having the above-described configuration and function has an amplification control circuit for generating a control signal through a low pass filter after converting an IF signal, which is an alternating current, inputted into a demodulation circuit into a direct current, and comparing it with a reference value. By controlling the amplification degree of the high frequency control amplifier and the IF gain control amplifier, the IF of a certain size is input to the demodulation circuit.

Claims (4)

수신된 위성방송신호중 불필요한 신호를 제거하는 입력필터와, 상기 입력필터에서 출력된 위성방송신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 고주파이득제어증폭기와, 상기 고주파이득제어증폭기에서 출력된 위성방송신호와 국부발진기에서 출력된 국부발진신호를 혼합하는 혼합기와, 상기 혼합기에서 출력된 신호중 IF대역만 통과시키는 IF대역통과필터와, 상기 IF대역통과필터에서 출력된 IF신호를 적절한 증폭도에 따라 일정한 크기로 증폭하는 IF이득제어증폭기와, 상기 IF이득제어증폭기에서 출력된 IF신호를 받아 상기 고주파이득제어증폭기와 중간주파수 이득제어증폭기의 증폭도를 제어하는 증폭도제어회로로 구성된 것을 특징으로 하는 위성방송 수신용 튜너.An input filter for removing unnecessary signals from the received satellite broadcast signals, a high frequency gain control amplifier for amplifying the satellite broadcast signal output from the input filter to a predetermined amplitude according to an appropriate amplification degree, and a satellite broadcast signal output from the high frequency gain control amplifier And a mixer for mixing the local oscillation signal output from the local oscillator, an IF bandpass filter for passing only the IF band among the signals output from the mixer, and an IF signal output from the IF bandpass filter with a predetermined amplitude according to an appropriate amplification degree. A tuner for satellite broadcasting reception comprising an IF gain control amplifier for amplifying and an amplification degree control circuit for controlling the amplification degree of the high frequency gain control amplifier and the intermediate frequency gain control amplifier in response to the IF signal output from the IF gain control amplifier. . 제1항에 있어서, 상기 증폭도제어회로는 IF이득제어증폭기에서 출력된 교류의 IF신호를 직류로 정류하는 IF직류변환회로와, 상기 IF직류변환회로에서 출력된 직류신호와 기준값을 비교하여 두 신호의 차를 출력하는 비교기와, 상기 비교기에서 출력된 신호중 저역만 통과시키는 저역통과필터로 구성된 것을 특징으로 하는 위성방송 수신용 튜너.2. The amplification degree control circuit of claim 1, wherein the amplification degree control circuit includes an IF direct current converting circuit for rectifying an AC signal of an alternating current output from an IF gain control amplifier into a direct current, and compares the direct current signal output from the IF direct current converting circuit with a reference value. And a low pass filter for passing only the low end of the signal output from the comparator. 제2항에 있어서, 상기 IF직류변환회로는 상기 IF이득제어증폭기에서 출력된 IF신호를 받아들이는 캐소드가 접지된 쇼트키베리어다이오드와, 상기 쇼트키베리어다이오드의 애노드에 캐소드가 연결된 쇼트키베리어다이오드와, 상기 쇼트키베리어다이오드의 애노드에 접지된 커패시터와, 상기 커패시터에 연결된 저항으로 구성된 것을 특징으로 하는 위성방송 수신용 튜너.The Schottky barrier diode of claim 2, wherein the IF DC conversion circuit comprises a schottky barrier diode having a grounded cathode for accepting an IF signal output from the IF gain control amplifier, and a schottky barrier diode having a cathode connected to an anode of the schottky barrier diode. And a capacitor grounded at the anode of the schottky barrier diode, and a resistor connected to the capacitor. 제2항에 있어서, 상기 비교기는 상기 IF직류변환회로부터 한 입력단에 입력된 직류신호를 다른 입력단에 인가된 기준값과 비교하여 입력된 두 신호의 차를 출력하는 연산증폭기로 구성된 것을 특징으로 하는 위성방송 수신용 튜너.The satellite of claim 2, wherein the comparator comprises an operational amplifier configured to output a difference between two input signals by comparing a DC signal input to one input terminal from the IF DC conversion circuit with a reference value applied to the other input terminal. Tuner for receiving broadcasts.
KR1019960030324A 1996-07-25 1996-07-25 Tuner for satellite broadcasting receiver KR0163857B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1019960030324A KR0163857B1 (en) 1996-07-25 1996-07-25 Tuner for satellite broadcasting receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1019960030324A KR0163857B1 (en) 1996-07-25 1996-07-25 Tuner for satellite broadcasting receiver

Publications (2)

Publication Number Publication Date
KR980012871A KR980012871A (en) 1998-04-30
KR0163857B1 true KR0163857B1 (en) 1999-03-20

Family

ID=19467457

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1019960030324A KR0163857B1 (en) 1996-07-25 1996-07-25 Tuner for satellite broadcasting receiver

Country Status (1)

Country Link
KR (1) KR0163857B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100434869B1 (en) * 2002-03-14 2004-06-22 (주)하이게인안테나 Frequency Band Convertable Low Noise Blockdown Converter

Also Published As

Publication number Publication date
KR980012871A (en) 1998-04-30

Similar Documents

Publication Publication Date Title
US5697091A (en) Distortion-free chopper-based signal mixer
US5073976A (en) Signal-to-noise ratio indicating circuit for fm receivers
US4864642A (en) Space diversity receiving system
US4249261A (en) Superheterodyne radio receiver with nearby-station interference detection
US4450586A (en) Automatic tuning device for FM receiver
EP0526662B1 (en) Circuit for sensing pulse-like noise in am receiver
US6211925B1 (en) Video intermediate-frequency signal processing device capable of receiving FM broadcasts
KR0163857B1 (en) Tuner for satellite broadcasting receiver
US4637066A (en) Noise blanking signal generator for AM radio
JP2845253B2 (en) Keyed pulse detection circuit
FI63144C (en) TELEVISION MACHINERY WITH A SYNCHRONOUS DETECTOR SCRAP OCH EN FREQUENCY DEVICE DETECTOR SCRAP
US3196354A (en) Signal to noise ratio controlled squelch circuit
EP0398351B1 (en) Apparatus for detecting broadcast FM satellite waves
CN114679230A (en) Radio frequency signal processing method and device and receiver
EP0344991B1 (en) AFC apparatus
US4633518A (en) AGC voltage generator with automatic rate switching
JP2827581B2 (en) Digital receiver
KR0178316B1 (en) Output of tunner controlling methd & device
US4530005A (en) AFC circuit for television tuner
KR100522462B1 (en) Carrier signal selective receiving device
US4163989A (en) Detector circuit for color television receivers
KR940005993Y1 (en) Sound intermediate frequency discriminator for tv receiver
JPH0746988Y2 (en) AGC control circuit of FM receiver
KR950000104Y1 (en) Carrier detection system
KR950001647Y1 (en) Voice signal autosearching circuit for satelltte broadcasting

Legal Events

Date Code Title Description
A201 Request for examination
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20020827

Year of fee payment: 5

LAPS Lapse due to unpaid annual fee