KR920006068B1 - Tv high-frequency signal control system in single up conversion type - Google Patents

Tv high-frequency signal control system in single up conversion type Download PDF

Info

Publication number
KR920006068B1
KR920006068B1 KR1019890016734A KR890016734A KR920006068B1 KR 920006068 B1 KR920006068 B1 KR 920006068B1 KR 1019890016734 A KR1019890016734 A KR 1019890016734A KR 890016734 A KR890016734 A KR 890016734A KR 920006068 B1 KR920006068 B1 KR 920006068B1
Authority
KR
South Korea
Prior art keywords
signal
stage
mixer
frequency
agc
Prior art date
Application number
KR1019890016734A
Other languages
Korean (ko)
Other versions
KR910011032A (en
Inventor
프레드릭형문
Original Assignee
삼성전기 주식회사
서주인
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 삼성전기 주식회사, 서주인 filed Critical 삼성전기 주식회사
Priority to KR1019890016734A priority Critical patent/KR920006068B1/en
Publication of KR910011032A publication Critical patent/KR910011032A/en
Application granted granted Critical
Publication of KR920006068B1 publication Critical patent/KR920006068B1/en

Links

Images

Classifications

    • 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
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Superheterodyne Receivers (AREA)

Abstract

Intermediate frequency signal is obtained by single conversion method and the IF signal is processed by a synchronisn detector to extract base band signal. The system includes a mixer (130) for generating intermediate frequency up to 2 GHz using RF input signal and a variable frequency signal generated by a voltage controlled osciallator (140), and a synchronism detector (200) for detecting synchronism to generate audio and video base band signal.

Description

싱글 컨버젼 방식을 이용한 TV 고주파 신호처리시스템TV high frequency signal processing system using single conversion method

제1도는 종래의 더블컨버젼 방식이 따른 TV 고주파 신호처리시스팀의 블록 다이아그램.1 is a block diagram of a TV high frequency signal processing system according to a conventional double conversion method.

제2도는 본 발명의 TV 고주파 신호 처리시스팀의 블록다이어그램.2 is a block diagram of a TV high frequency signal processing system of the present invention.

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

110 : 튜너블 밴드패스 필터단 120 : RF 증폭단110: tunable band pass filter stage 120: RF amplifier stage

130 : 믹서단 140 : VCO(Voltage-Controlled Oscillator)130: mixer stage 140: VCO (Voltage-Controlled Oscillator)

160 : IF 증폭단 200 : 동기 디텍더160: IF amplifier stage 200: synchronous detector

210,240 : 믹서단 230 : LO(Local Oscillator)210,240 Mixer stage 230: LO (Local Oscillator)

본 발명은 싱글 업 컨버젼(Single up Conversion)형식을 통하여 더블 컨버젼 형식에 따른 튜너 특성을 얻을 수 있는 싱글 컨버젼 방식을 이용한 TV 고주파 신호 처리시스팀에 관한 것이다.The present invention relates to a TV high frequency signal processing system using a single conversion method that can obtain a tuner characteristic according to a double conversion format through a single up conversion format.

TV나 VCR에 사용되는 VVC튜너는 통상 더블 컨버젼 방식으로 설계되고 있으며 그 일예의 구성을 제1도에서 도시하고 있다. 여기에서 참조되는 뱌와같이, 50-800MHz의 RF 신호가 업 컨버터단(10)에 입력되면, 이 RF 입력신호는 VCO(Voltage Controlled Oscillator)(20)의 가변발진주파수에 의해 1GHz대의 높은 주파수 신호 (1차 IF신호)로 업 컨터팅 된다. 상기 업 컨버터단(10)에서 높은 주파수로 변환된 RF 신호는 밴드 패스 필터(30)를 통하여 더운 컨버터단(40)에 입력되며, 여기에서 LO(Local Oscillator)(50)의 고정발진 주파수로 다운 컨버팅되어 45MHz대의 2차 IF신호로 변환된다. 이와같이 다운 컨버터단(40)에서 출력되는 2차 IF신호는 IF 증폭단(60)에서 증폭된후, 동기 디텍터(70)에서 VCO(80)의 가변발진주파수에 따라 오디오 및 비디오의 베이스 밴드 신호가 동기 검출되어 출력된다.A VVC tuner used for a TV or a VCR is usually designed in a double conversion method, and an example of the configuration thereof is shown in FIG. As shown here, when a 50-800 MHz RF signal is input to the up-converter stage 10, this RF input signal is a high frequency signal of 1 GHz band by the variable oscillation frequency of the voltage controlled oscillator (VCO) 20. Up-conversion to (primary IF signal). The RF signal converted to the high frequency in the up converter stage 10 is input to the hot converter stage 40 through a band pass filter 30, where it is down to the fixed oscillation frequency of the local oscillator (LO) 50. It is converted and converted into a second IF signal in the 45MHz band. As such, the second IF signal output from the down converter stage 40 is amplified by the IF amplifier stage 60, and then the baseband signals of the audio and video are synchronized by the synchronous detector 70 according to the variable oscillation frequency of the VCO 80. It is detected and output.

그러나, 상기와 같은 더블 컨버젼 방식의 TV고주파 신호 처리 방식에서는 업 컨버터단과 다운 컨버터단이 각각 독립적으로 설계되지 않으면 VCO와 LO간의 상호 간섭에 따른 비트 발생 및 영상주파수 발생을 억제할 수 없다. 특히 업 컨버터단과 다운 컨버터단을 각각 독립적으로 설계하는 경우, 튜너의 IC화가 매우 곤란하게 되며, 또한 이들의 차폐를 완벽하게 가져가지 않으면 원하는 튜너특성을 얻을수가 없다. 한편, 업다운 컨버터단의 완벽한 차폐를 현실적으로 해결하기에는 상당한 추가 비용과 제작상의 어려움이 따르게 된다.However, in the double conversion TV high frequency signal processing method as described above, unless the up converter stage and the down converter stage are independently designed, bit generation and image frequency generation due to mutual interference between the VCO and the LO cannot be suppressed. In particular, when the up-converter stage and the down-converter stage are designed independently, the IC of the tuner becomes very difficult, and the desired tuner characteristics cannot be obtained unless these shields are completely shielded. On the other hand, the realistic shielding of the complete shielding of the up-down converter stages involves significant additional costs and manufacturing difficulties.

본 발명은 이와같은 종래의 더블 컨버젼 TV 튜너의 문제점을 해결하기 위한것으로, 업컨버터단의 RF신호 변환출력이 다운 컨버터단을 거치지 않고 직접 동기 디텍터로 입력되게 구성하고, 상기 동기 디텍터에서는 변환된 IF 신호에서 직접 베이스 밴드 신호가 출력되게 함으로써, TV 튜너의 컴팩트 설계 및 IC화를 가능하게 하고 또한 비트 발생 및 영상주파수 발생을 제거하여 고화질을 얻을수 있는 싱글컨버젼 방식을 이용한 TV 고주파 신호처리 시스팀을 제공하는데 그 목적이 있다.The present invention is to solve the problem of the conventional double-conversion TV tuner, the RF signal conversion output of the up-converter stage is configured to be input directly to the synchronous detector without going through the down-converter stage, the IF is converted in the synchronous detector By outputting baseband signal directly from signal, it enables compact design and ICization of TV tuner, and provides TV high frequency signal processing system using single conversion method that can obtain high quality by eliminating bit generation and video frequency generation. The purpose is.

이하 첨부한 도면에 따라 본 발명의 실시예를 설명하면 다음과 같다. 제2도에서 도시하고 있는 바와같이, 50-800MHz의 RF 입력신호는 튜너블 밴드 패스 필터단(110)과 RF 증폭단(120)을 거쳐 업컨버팅을 위한 믹서단(130)으로 제공되게 구성한다.Hereinafter, an embodiment of the present invention according to the accompanying drawings. As shown in FIG. 2, the RF input signal of 50-800 MHz is configured to be provided to the mixer stage 130 for upconverting through the tunable band pass filter stage 110 and the RF amplifier stage 120.

상기 튜너블 밴드 패스 필터단(110)은 튜너의 외부 튜닝전압에 따라 패스밴드가 결정되는 가변밴드 패스필터회로로 마련되며, 통상 바랙터 다이오드를 이용하여 간단하게 구현할 수 있다. 상기 RF 증폭단(120)은 널리 알려진 키이드(Keyed) AGC단(170)에 의해 그 증폭이득이 자동조절되는 저잡음 AGC 증폭회로로 마련된다. 상기 RF 증폭단(120)에서 출력되는 RF 신호는 믹서단(130)에서 높은 발진 주파수를 갖는 VCO(140)의 출력으로 2GHz대의 초고주파수로 변환되게 구성하고, 이렇게 업 컨버젼된 1차 IF신호, 즉 믹서단(130)의 출력신호는 앤드패스 필터단(150)와 IF증폭단(160)을 거쳐 동기 디텍터(200)로 직접 제공되게 구성한다. 상기 IF 증폭단(160) 또한 키이드 AGC단(170)에 의해 자동이득 조절되는 증폭회로로 마련된다. 상기 동기 디텍터(200)는 2GHz대의 높는 주파수로 변환된 IF신호가 90°의 위상차를 갖는 LO(230)의 국부발진주파수로 각각의 믹서단(210,240)에서 믹싱되어 로우패스용 IF필터(250)를 거쳐 베이스 밴드의 오디오 및 비디오 신호가 동기 검출되도록 구성한다.The tunable band pass filter stage 110 is provided as a variable band pass filter circuit in which a pass band is determined according to an external tuning voltage of a tuner, and can be simply implemented using a varactor diode. The RF amplification stage 120 is provided with a low noise AGC amplification circuit whose amplification gain is automatically adjusted by a well-known Keyed AGC stage 170. The RF signal output from the RF amplifier stage 120 is configured to be converted to the ultra-high frequency of the 2GHz band to the output of the VCO 140 having a high oscillation frequency in the mixer stage 130, i.e. The output signal of the mixer stage 130 is configured to be directly provided to the synchronous detector 200 via the end pass filter stage 150 and the IF amplifier stage 160. The IF amplifier stage 160 is also provided as an amplification circuit that is automatically controlled by the key AGC stage 170. The synchronous detector 200 is a low pass IF filter 250 is mixed in each mixer stage (210,240) of the IF signal converted to a high frequency of 2GHz band local oscillation frequency of LO 230 having a phase difference of 90 ° The audio and video signals of the base band are synchronously detected through the configuration.

여기에서 믹서단(210)의 출력은 IF필터단(220), 즉 로우패스필터회로를 거쳐 LO(230)에 공급함으로써 상기 LO(230)의 국부발진 출력주파수에서 90°의 위상차가 발생되게 구성한다. 상기 동기 디텍터(200)에서 출력되는 최종 베이스 밴드 신호의 일부는 앞에서 설명한 바와같이 RF 및 IF 증폭단(120,160)에 AGC신호를 제공하는 키이드 AGC단(170)에 AGC제어신호 발생원으로 제공되게 구성한다.Here, the output of the mixer stage 210 is configured to generate a phase difference of 90 ° at the local oscillation output frequency of the LO 230 by supplying it to the LO 230 through the IF filter stage 220, that is, the low pass filter circuit. do. A part of the final baseband signal output from the synchronous detector 200 is configured to be provided as an AGC control signal source to the keyed AGC stage 170 which provides the AGC signal to the RF and IF amplifier stages 120 and 160 as described above. .

이와같은 구성된 본 발명의 동작 및 그에 따른 효과를 설명하면 다음과 같다.Referring to the operation of the present invention configured as described above and the effects thereof are as follows.

제2도에서, 50-80MHz RF입력신호는 튜너를 밴드패스필터단(110)에서 외부 튜닝전압에 따라 결정되는 원하는 주파수 밴드의 RF 신호와 필터링되어 출력된다. 이러한 RF 신호는 보편화된 키이드 AGC단(170)의 RF AGC신호에 따라 이득이 자동조절되는 RF 증폭단(120)을 거쳐 업컨버젼을 위한 믹서단(130)으로 제공된다.In FIG. 2, the 50-80 MHz RF input signal is output after the tuner is filtered with the RF signal of the desired frequency band determined by the band pass filter stage 110 according to the external tuning voltage. The RF signal is provided to the mixer stage 130 for upconversion via the RF amplifier stage 120 whose gain is automatically adjusted according to the RF AGC signal of the generalized keyed AGC stage 170.

상기 믹서단(130)에 입력된 RF 신호는 VCO(140)의 발진주파수에 의해 대단히 높은 2GHz대의 IF신호로 업 컨버팅되어 출력된다. 이러한 IF신호는 밴드패스 필터단(150)과 키이드 AGC단(170)에 의해 AGC되는 IF증폭단(160)을 거쳐 동기 디텍터(200)에 입력된다. 이때 1차 IF신호는 대단히 높은 주파수 대(2GHz대)이기 때문에 영상 및 IF 리젝션 방해주파수의 영향범위 외부로 놓여지게 되므로, 동기 디텍터(200)에서 베이스 밴드 신호를 추출하기 위한 디텍트 처리시, 영상등의 방해파에 의한 영향을 배제 시킬 수 있게 된다.The RF signal input to the mixer stage 130 is up-converted into an IF signal of a very high 2 GHz band by the oscillation frequency of the VCO 140 and output. The IF signal is input to the synchronous detector 200 through the IF amplifier stage 160 which is AGC by the band pass filter stage 150 and the key AGC stage 170. At this time, since the first IF signal is a very high frequency band (2 GHz band), the first IF signal is placed outside the influence range of the image and IF rejection disturbance frequency, so that the detection process for extracting the baseband signal from the sync detector 200, It is possible to eliminate the influence of interference waves such as images.

한편, 동기 디텍터(200)는 2GHz대 높은 고주파수로 업 컨버젼된 TV IF신호를 각 믹서단(210,240)으로 받아, 일정한 위상차(90°)의 국부발진주파수를 발생하는 LO(230의 각 발진주파수로 직접 동기 검출하여 방해파의 영향없이 오디오 및 비디오의 베이드 밴드 신호를 출력하게 된다. 또한, 상기 동기 디텍터(200)의 베이스 밴드 신호출력의 일부는 키이드 AGC단(170)에 입력되므로, 베이스 밴드 신호 세기에 따라 제어 신호 출력을 달리하여 RF 증폭단(120) 및 IF증폭단(160)의 이득을 안정화 시키게 된다.On the other hand, the synchronous detector 200 receives a TV IF signal, which is upconverted at a high frequency of 2 GHz, to each mixer stage 210 and 240, and generates a local oscillation frequency of a constant phase difference (90 °) at each oscillation frequency of the LO 230. Direct synchronization is detected to output a bad band signal of audio and video without the influence of interference waves, and since a part of the baseband signal output of the synchronization detector 200 is input to the keyed AGC stage 170, the baseband The control signal output is changed according to the signal strength to stabilize the gain of the RF amplifier 120 and the IF amplifier 160.

따라서 본 발명은 한번의 RF 입력신호 업 컨버팅, 즉 싱글컨버젼 방식을 통하여 방해파의 영향을 받지않는 매우 높은 주파수대의 IF 신호를 얻고, 이 IF 신호를 직접 동기 디텍터에서 처리하여 베이스 밴드 신호를 추출하게 됨에 따라, 튜너 회로 구성의 간소화 및 IC화가 가능하게 되어 튜너제품 원가 절감 및 생산성 향상 효과를 얻을 수 있다.Therefore, the present invention obtains a very high frequency IF signal which is not affected by the interference wave through the single RF input signal up-conversion, that is, single conversion method, and extracts the baseband signal by processing the IF signal directly in the synchronous detector. Accordingly, the tuner circuit configuration can be simplified and the IC can be realized, thereby reducing the cost of the tuner product and improving the productivity.

Claims (1)

고주파 TV 신호에서 베이스 밴드 신호를 추출하기위한 튜너에 있어서, 튜너블 밴드 패스 필터단(110)과 키이드 AGC 제어되는 RF 증폭단(120)올 거친 RF 입력신호가 믹서단(130)에서 VCO(140)의 가변발진주파수에 의해 2GHz대의 IF신호로 업 컨버젼되게 구성하고, 상기 IF신호는 밴드패스 필터단(150)과 키이드 AGC 제어되는 IF증폭단(160)을 거쳐서 2개의 믹서단(210,240)과 상기 믹서단(210,240)에 90°의 위상차의 국부발진주파수를 공급하는 LO(230)를 포함하는 동기 디텍터(200)에서 직접 동기 검출되어 오디오및 비디오 베이스 밴드 신호로 출력되게 구성하는 것을 특징으로 하는 싱글 컨버젼 방식을 이용한 TV 고주파 신호처리 시스팀.In the tuner for extracting the baseband signal from the high-frequency TV signal, the tunable band pass filter stage 110 and the key AGC-controlled RF amplifier stage 120, the coarse RF input signal from the mixer stage 130 VCO (140) The IF signal is up-converted to a 2 GHz IF signal by the variable oscillation frequency of the band), and the IF signal is passed through two mixer stages 210 and 240 through a band pass filter stage 150 and a key AGC controlled IF amplifier stage 160. It is characterized in that it is configured to be directly detected by the sync detector 200 including a LO 230 for supplying a local oscillation frequency of 90 ° phase difference to the mixer stage (210,240) and output as an audio and video baseband signal TV high frequency signal processing system using single conversion method.
KR1019890016734A 1989-11-18 1989-11-18 Tv high-frequency signal control system in single up conversion type KR920006068B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1019890016734A KR920006068B1 (en) 1989-11-18 1989-11-18 Tv high-frequency signal control system in single up conversion type

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1019890016734A KR920006068B1 (en) 1989-11-18 1989-11-18 Tv high-frequency signal control system in single up conversion type

Publications (2)

Publication Number Publication Date
KR910011032A KR910011032A (en) 1991-06-29
KR920006068B1 true KR920006068B1 (en) 1992-07-27

Family

ID=19291770

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1019890016734A KR920006068B1 (en) 1989-11-18 1989-11-18 Tv high-frequency signal control system in single up conversion type

Country Status (1)

Country Link
KR (1) KR920006068B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100764372B1 (en) * 2005-10-11 2007-10-08 삼성전기주식회사 One-cam type dual tuning system for digital television

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100764372B1 (en) * 2005-10-11 2007-10-08 삼성전기주식회사 One-cam type dual tuning system for digital television

Also Published As

Publication number Publication date
KR910011032A (en) 1991-06-29

Similar Documents

Publication Publication Date Title
KR100216318B1 (en) Homodyne receiver for catv converter
US5200826A (en) TV signal receiving double conversion television tuner system having automatic gain control provisions
US5930696A (en) Broadband low-noise low-intermodulation receiver
CA2104182C (en) Double conversion digital tuning system
US6163684A (en) Broadband frequency synthesizer
CA2010176C (en) Tuner station selecting apparatus
US7949072B2 (en) Local oscillator with injection pulling suppression and spurious products filtering
KR920006068B1 (en) Tv high-frequency signal control system in single up conversion type
CA1149877A (en) Circuit arrangement for a wide-band vhf-uhf television double superheterodyne receiver
JP2001177779A (en) Video intermediate frequency processor
JP2001339652A (en) Television tuner
KR0147054B1 (en) Frequency synthesizer type television signal receiving apparatus comprising aft function and controlling method therefor
JPH01300772A (en) Video intermediate frequency signal processing circuit
US5640688A (en) Tuner and splitter-modulator circuit having a common quartz crystal
US8023922B2 (en) Receiver for simultaneously receiving different standards
KR960000141B1 (en) Radio receiver circuit
KR930002607B1 (en) Tv channel modulation circuit
US4164710A (en) Very high frequency tuner for eliminating image interference and stray capacitance effects
US4099123A (en) Electrical multi-channel signal transmission systems
KR0130840Y1 (en) Frequency sellecting circuit
JP2563022B2 (en) Retransmit single channel signal processor
KR960002666B1 (en) Double converter tuner
US5237419A (en) Television signal repeater with improved aural separation
KR20020030379A (en) Double conversion type tuner for using trap circuit
KR0124732Y1 (en) Frequency selecting apparatus of double conversion tuner

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
G160 Decision to publish patent application
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
LAPS Lapse due to unpaid annual fee