KR870001636B1 - Noise silence circuit of a automatic gain regulator - Google Patents

Noise silence circuit of a automatic gain regulator Download PDF

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KR870001636B1
KR870001636B1 KR1019850001979A KR850001979A KR870001636B1 KR 870001636 B1 KR870001636 B1 KR 870001636B1 KR 1019850001979 A KR1019850001979 A KR 1019850001979A KR 850001979 A KR850001979 A KR 850001979A KR 870001636 B1 KR870001636 B1 KR 870001636B1
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input
diode
capacitor
output terminal
gain regulator
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KR860007790A (en
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고성석
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동양정밀공업 주식회사
권혁조
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference

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  • Computer Networks & Wireless Communication (AREA)
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  • Control Of Amplification And Gain Control (AREA)
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Abstract

This invention relates to a noise suppression circuit of automatic gain regulation due to input signal level to eliminate surrounding noise in the middle of communication. The systems are composed of an audio amp circuit and a band pass filter comparator, a gain regulator. And capacitors are used for band pass filter output terminals which hold high level input signal. The voltage at anode of diode due to rectification applies to a multiplier which compares with reference voltage of op amp. And the output of op amp is connected to serial diode(D1, D2, D3, D4) which switch the connection.

Description

입력신호 레벨에 따른 자동이득 조정기의 잡음 억제회로Noise Suppression Circuit of Automatic Gain Regulator According to Input Signal Level

제1도는 본 발명의 상세 회로도.1 is a detailed circuit diagram of the present invention.

제2도는 제1도의 이득조정기(4)를 트랜지스터로 직렬 연결한 다른 실시예.2 is another embodiment in which the gain regulator 4 of FIG. 1 is connected in series with a transistor.

본 발명은 무선통신기기의 오디오 증폭회로부에 부가한 회로로서, 통화 중간에 발생하는 통화자 주변잡음을 제거하기 위한 입력신호 레벨에 따른 자동 이득조정기의 잡음억제 회로에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio amplifying circuit portion of a wireless communication device, and more particularly, to a noise suppression circuit of an automatic gain adjuster according to an input signal level for removing a peripheral noise generated during a call.

종래에는 송수화자가 통화를 할 경우 상대방의 음성신호외에도 주위의 소음이 들려 의사전달이 명확하지 못해 통화에 상당한 어려움을 주었다.In the related art, when a talker makes a call, the noise of the surroundings is heard in addition to the voice signal of the other party, so communication is not clear, which causes a considerable difficulty in the call.

본 발명은 상기와 같은 종래의 결점을 해결하고져 발명한 것으로서 통화품질을 개선하여 송수화자의 음성을 명확하게 전달할 수 있도록 하였다.The present invention solves the above-mentioned drawbacks as described above and improves the call quality so that the voice of the handset can be clearly transmitted.

본 발명을 첨부된 도면에 의거회로 구성 및 작용 효과를 상세히 설명하면 다음과 같다.Referring to the present invention with reference to the accompanying drawings, the configuration and operation effects in detail as follows.

제1도는 오디오증폭회로(1), 대역통과필터(2), 비교기(3), 이득조정기(4)로 구성된 것으로서 오디오증폭회로(1)의 입력단에 입력된 신호가 대역통과 필터(2)에 입력되면 일정레벨로 대역 통과되어 입력신호 레벨이 높은 경우 콘덴서(C6)를 충전시키며, 충전된 전압이 다시 방전하면 비교기(3)에 입력되어 기준 전압과 비교되므로서, 비교기(3)의 출력단에(-)전위가 나타나 직렬 다이오드(D3, D4)로 구성된 이득조정기(4)에 순방향 바이어스가 걸리므로 이득조정기(4)의 임피던스가 저 임피던스(수십 KΩ)로 된다.1 is composed of an audio amplifier circuit 1, a band pass filter 2, a comparator 3, a gain adjuster 4, and a signal input to the input terminal of the audio amplifier circuit 1 is applied to the band pass filter 2. When input, the band is passed through a predetermined level, and when the input signal level is high, the capacitor C6 is charged, and when the charged voltage is discharged again, it is input to the comparator 3 and compared with the reference voltage, so that the output terminal of the comparator 3 The negative potential appears and a forward bias is applied to the gain regulator 4 composed of the series diodes D3 and D4, so that the impedance of the gain regulator 4 becomes low impedance (tens of KΩ).

따라서, 오디오 증폭회로(1)의 저항(R1)과 이득조정기(4)가 병렬연결상태이므로 병렬합성 저항값은 작아지게 되어 오디오 증폭회로(1)의 출력단 이득은 커지게되고, 만일 오디오증폭회로(1)의 입력단 에입력된 신호의 레벨이 낮을 경우 대역통과필터(2)를 거친신호가 콘덴서(C6)를 충전시키지 못하므로 비교기(3)의 기준전압보다 전위가 낮아지게 되어 비교기(3)의 출력단(+)에 전위가 나타나 이득조정기(4)에 역방향 바이어스가 걸리므로 이득조정기(4)의 임피던스가 고임피던스수(MΩ)로 된다.Therefore, since the resistance R1 of the audio amplifier circuit 1 and the gain regulator 4 are in parallel connection state, the parallel synthesis resistance value becomes small, and the output stage gain of the audio amplifier circuit 1 becomes large. When the level of the signal input to the input terminal of (1) is low, the signal passing through the band pass filter (2) does not charge the capacitor (C6), the potential is lower than the reference voltage of the comparator (3) and the comparator (3) Since the potential appears at the output terminal (+), reverse bias is applied to the gain regulator 4, so that the impedance of the gain regulator 4 becomes a high impedance number MΩ.

따라서, 병렬합성 저항값은 커지게 되어 오디오증폭회로(1)의 출력단 이득은 작아지게된다.Therefore, the parallel synthesis resistance value becomes large, and the output stage gain of the audio amplifier circuit 1 becomes small.

본 발명의 작용효과를 좀더 자세히 설명하면 다음과같다.Referring to the effects of the present invention in more detail as follows.

OP엠프(Q1)의 입력단자에 300-3000KHz의 음성주파수가 입력되면 이음성신호는 커프링(COUPLING)용콘덴서(C1)를 거쳐 저항(R1)을 통해 OP엠프(Q1)의 (+)입력단자로 전달되고, 또한 저항(R5)을 거쳐 OP엠프(Q2)의(+)입력단자에 전달되어, 일정 레벨의 음성신호가 대역통과하여 커풀링콘덴서(C5)를 거쳐 저항(R12)을 통해 OP엠프(Q3)의(-)입력단자로 입력된다.When the voice frequency of 300-3000KHz is input to the input terminal of the OP amplifier Q1, the negative audio signal is input to the positive input of the OP amplifier Q1 through the resistor R1 through the capacitor C1 for the coupling. It is transmitted to the terminal, and is also passed to the (+) input terminal of the OP amplifier Q 2 via the resistor R5, and the voice signal of a predetermined level is passed through the coupling capacitor C5 to pass the resistor R12. Through the (-) input terminal of the OP amplifier (Q3).

이때, OP엠프(Q3)의 출력단에도 음성신호 주파수가 대역통과 하여 일정레벨의 음성신호로 나타나게 된다. 일정레벨의 음성신호는 콘덴서(C6)에 충전되었다가 다시 방전하면 다이오드(D5)를 통해 OP엠프(Q3)의 출력단자로 입력되어 접지되고, 다이오드(D5)의 정류작용에 의해 애노오드에(+)전위가 나타나며, 저항(R19)을 통해 OP엠프(Q4)의(-)입력단자에 입력되면 OP엠프(Q4)의 출력단은(-)전위가 되어

Figure kpo00001
의 전원입력단자에서 공급된 전원이 저항(R21) 및 다이오드(D3, D4)를 거쳐 순방향 바이어스 되어 저항(R22)을 통해 OP엠프(Q4)의 출력단으로 접지된다. 그러므로 이때에는 다이오드의 특성에 의해 동(動)저항값이 작아지므로 이득을 변화시키는 임피던스가 저임피던스로 된다. 저항(R1)과 직렬 다이오드(D3, D4)는 방법 연결상태이므로 병렬합성 저항값은 작아지게 되어 OP엠프(Q1)의 출력단 이득은 커진다.At this time, the voice signal frequency is also passed through the output terminal of the OP amplifier Q3 to appear as a voice signal of a predetermined level. When the voice signal of a predetermined level is charged in the capacitor C6 and then discharged again, it is input to the output terminal of the OP amplifier Q3 through the diode D5 and grounded. +) Potential appears, and when input to the negative input terminal of the OP amplifier Q4 through the resistor (R19), the output terminal of the OP amplifier (Q4) becomes (-) potential
Figure kpo00001
The power supplied from the power input terminal of is forward biased through the resistors R21 and diodes D3 and D4, and is grounded to the output terminal of the OP amplifier Q4 through the resistor R22. Therefore, at this time, the dynamic resistance value becomes small due to the characteristics of the diode, so the impedance which changes the gain becomes low impedance. Since the resistor R1 and the series diodes D3 and D4 are in a method-connected state, the value of the parallel synthesis resistance is reduced, and the output stage gain of the OP amplifier Q1 is increased.

OP엠프(Q1)의 입력단에 음성신호보다 신호레벨이 낮은 소음신호가 입력되면 이 소음신호는 상술한 바와같이 음성신호가 입력되는 과정과 동일한 경로를 거치게 되나, OP엠프(Q3)의 출력단에 나타난 신호가 음성신호보다 작은 레벨이므로 콘덴서(C6)를 충전시키지 못하게 된다. 따라서, OP엠프(Q4)의 출력단에 (+)전위가 나타난다. 이때에는 직렬 다이오드(D1, D2, D3, D4)가 역방향바이어스가되어 고임피던스로 되므로, 저항(R1)과 직렬다이오드(D1, D2, D3, D4)의 병렬합성 저항값은 커지게되어 OP엠프(Q1)의 출력단 이득은 작아지게 된다.When the noise signal having a lower signal level than the voice signal is input to the input terminal of the OP amplifier Q1, the noise signal passes through the same path as that of the voice signal input as described above, but appears at the output terminal of the OP amplifier Q3. Since the signal is at a level lower than that of the audio signal, the capacitor C6 cannot be charged. Therefore, a positive potential appears at the output terminal of the OP amplifier Q4. At this time, since the series diodes D1, D2, D3, and D4 become reverse biased to have high impedance, the parallel synthesis resistance of the resistor R1 and the series diodes D1, D2, D3, and D4 becomes large, resulting in an OP amplifier. The output stage gain of (Q1) becomes small.

제1도의 이득조정기(4) 내부회로를 4개의 직렬 다이오드(D1, D2, D3, D4) 대신에 제2도에서와 같이 NPN트랜지스터의 베이스와 콜렉터를 단락시키면 다이오드의 애노오드와 특성이 같고, 나머지 에미터는 다이오드의 캐소오드와 특성이 같으므로 전술한 바와같은 NPN트랜지스터(T1, T2, T3, T4)를 직렬접속하여 이득조정기(4)를 구성할 수도 있다.If the internal circuit of the gain regulator 4 of FIG. 1 is shorted to the base and collector of the NPN transistor as shown in FIG. 2 instead of four series diodes D1, D2, D3, and D4, the diode has the same characteristics as the anode. Since the remaining emitters have the same characteristics as the cathode of the diode, the gain regulator 4 may be configured by connecting the NPN transistors T1, T2, T3, and T4 in series as described above.

서상에서와 같이, 본 발명은 음성신호의 이득을 크게하고 소음신호의 이득을 적게 하므로서 통화품질을 매우 좋게하여 맑고, 깨끗한 음성을 들을 수 있도록 발명한 것이다.As in the textbook, the present invention has been invented so that the call quality can be very good and the clear and clear voice can be heard by increasing the gain of the voice signal and reducing the gain of the noise signal.

Claims (1)

본문에 설명되고 도면에 도시된 바와같이, 오디오 증폭회로(1)의 입력단(A)에 입력되는 신호를 일정레벨로 여파할 수 있도록 2개의 OP엠프(Q2, Q3)로 구성된 대역통과필터(2)를 연결하고 입력된 신호의 레벨이 높을 경우 콘덴서(C6)가 충전될 수 있도록 대역통과필터(2)의 출력단(B)에 콘덴서(C6)를 연결하되, 출력단(B)과 콘덴서(C6)사이에는 출력단(B)쪽에 다이오드(D5)의 캐소오드를 콘덴서(C6)쪽에 다이오드(D5)의 애노오드를 연결접속하며, 입력신호 레벨에 따른 콘덴서(C6)의 충전 여부로 정류작용에 의한 다이오드(D5)의 애노오드에 나타난 전위가 배교기(3)에 입력되어 OP엠프(Q4)의 기준전압과 비교되므로서, OP엠프(Q4)의 출력단에 나타난 전위가(+) 혹은 (-)로 되어 이득조정기(4)의 직렬 다이모드(D1, D2, D3, D4)의 동저항값을 저임피던스에서 고임피던스로 스위칭되도록 상호 연결하여 구성한 것을 특징으로 하는 입력신호 레벨에 따른 자동 이득조정기의 잡음 억제회로.As described herein and shown in the drawings, a bandpass filter 2 composed of two OP amplifiers Q2 and Q3 so as to filter a signal input to the input terminal A of the audio amplifier circuit 1 to a predetermined level. ) And connect the capacitor (C6) to the output terminal (B) of the bandpass filter (2) to charge the capacitor (C6) when the level of the input signal is high, but the output terminal (B) and the capacitor (C6) The diode of the diode D5 is connected to the output terminal B between the cathode of the diode D5 and the anode of the diode D5 to the capacitor C6. Since the potential shown at the anode of (D5) is input to the cross-linker 3 and compared with the reference voltage of the OP amp Q4, the potential shown at the output terminal of the OP amp Q4 is set to (+) or (-). The dynamic resistance of the series die modes D1, D2, D3 and D4 of the gain regulator 4 is switched from low impedance to high impedance. Rock interconnect to the noise suppression of the automatic gain regulator according to the input signal level, characterized in that the circuit is configured.
KR1019850001979A 1985-03-26 1985-03-26 Noise silence circuit of a automatic gain regulator KR870001636B1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007029899A1 (en) * 2005-09-05 2007-03-15 Pishon Anc Co., Ltd. Apparatus and method for removing ambient noise and mobile communication terminal equipped with the apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007029899A1 (en) * 2005-09-05 2007-03-15 Pishon Anc Co., Ltd. Apparatus and method for removing ambient noise and mobile communication terminal equipped with the apparatus

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