JPH0421364B2 - - Google Patents
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- Publication number
- JPH0421364B2 JPH0421364B2 JP58125656A JP12565683A JPH0421364B2 JP H0421364 B2 JPH0421364 B2 JP H0421364B2 JP 58125656 A JP58125656 A JP 58125656A JP 12565683 A JP12565683 A JP 12565683A JP H0421364 B2 JPH0421364 B2 JP H0421364B2
- Authority
- JP
- Japan
- Prior art keywords
- amplifier
- detection circuit
- output
- gain control
- stage
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
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- 230000003321 amplification Effects 0.000 description 10
- 238000003199 nucleic acid amplification method Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 6
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- 101100165799 Arabidopsis thaliana CYP86A2 gene Proteins 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 2
- 101710170230 Antimicrobial peptide 1 Proteins 0.000 description 1
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- Control Of Amplification And Gain Control (AREA)
Description
【発明の詳細な説明】
(1) 発明の技術分野
本発明は出力信号レベルを種々の値としても増
幅器構成を大きく変化させることが無く、安定な
動作の得られる自動利得制御増幅器に関する。DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an automatic gain control amplifier that can provide stable operation even when the output signal level is varied to various values without significantly changing the amplifier configuration.
(2) 従来技術と問題点
帰還型自動利得制御増幅器として第１図に示す
構成のものは周知である。即ち信号増幅段AMP
１乃至AMP５を各段間に可変減衰器ATT１乃至
ATT４を介して縦続接続している。増幅器AMP
５の出力から検波回路DTと直流増幅器DCAを介
して制御回路CTLを駆動し、制御回路CTLの出
力により可変減衰器を制御し、最終増幅段AMP
５の出力を所定値に維持している。(2) Prior art and problems The feedback type automatic gain control amplifier having the configuration shown in FIG. 1 is well known. That is, signal amplification stage AMP
1 to AMP5 with variable attenuators ATT1 to ATT1 to AMP5 between each stage.
Cascade connection is made via ATT4. amplifier AMP
The output of 5 drives the control circuit CTL via the detection circuit DT and the DC amplifier DCA, and the output of the control circuit CTL controls the variable attenuator, and the final amplifier stage AMP
5 is maintained at a predetermined value.
このような利得制御は最終増幅段AMP５の出
力における振幅変化、即ち入力信号の振幅変動・
中間増幅段の利得変化・検波回路の微小な変化な
どに基づく変動を打ち消すように自動的に制御で
きる。最終増幅段AMP５の出力のレベル設定と
して前記変動と比較し、極めて大きく変化させた
状態において利得制御増幅器を使用する場合があ
る。それは、近年、無線通信用伝送設備としてデ
イジタル信号を使用することが実用化されて来
た。一般に無線通信用伝送設備内に自動利得制御
回路付きの増幅器を多数使用しているが、増幅器
出力レベルの設定値として＋5dBのもの、−10dB
のもの、のように出力レベルの設定値が大きく異
なる増幅器を必要とする。そのとき出力レベルの
設定値が異なるのみで増幅段数の等しいものを使
用することは、出力レベル毎に違つた利得を持つ
増幅器を複数組設計することより有利である。し
たがつて第１図に示す増幅器における可変減衰器
ATT１〜ATT４、或いは制御回路CTLにおけ
る制御基準電位を変更することなどにより、出力
端子OUTの出力レベルを所定値に設定した増幅
器とすることが出来るから、そのように調整した
増幅器を所定の場所で使用している。しかしその
ように調整することは、例えば或る可変減衰器を
調整し、出力レベル設定値の試験をしてから他の
減衰器の調整をすることを、繰り返す必要があつ
て調整が複雑で難しいことであつた。 Such gain control is based on the amplitude change in the output of the final amplification stage AMP5, that is, the amplitude fluctuation of the input signal.
It can be automatically controlled to cancel out fluctuations caused by changes in the gain of the intermediate amplifier stage, minute changes in the detection circuit, etc. In some cases, a gain control amplifier is used to set the level of the output of the final amplification stage AMP5 with a very large change compared to the above fluctuation. In recent years, the use of digital signals as transmission equipment for wireless communications has come into practical use. Generally, many amplifiers with automatic gain control circuits are used in wireless communication transmission equipment, and the amplifier output level settings are +5 dB and -10 dB.
require amplifiers with widely different output level settings, such as those in In this case, using amplifiers with the same number of amplification stages but with different output level settings is more advantageous than designing multiple sets of amplifiers with different gains for each output level. Therefore, the variable attenuator in the amplifier shown in FIG.
By changing the control reference potential in ATT1 to ATT4 or the control circuit CTL, it is possible to create an amplifier with the output level of the output terminal OUT set to a predetermined value. I am using it. However, such adjustment is complicated and difficult because it requires repeating, for example, adjusting a certain variable attenuator, testing the output level setting value, and then adjusting other attenuators. It happened.
(3) 発明の目的
本発明の目的は前述の欠点を改善し、出力レベ
ルを種々の値としても、増幅段構成を大きく変化
させることがなく、動作の安定な自動利得制御増
幅段を提供することにある。(3) Purpose of the Invention The purpose of the present invention is to improve the above-mentioned drawbacks and provide an automatic gain control amplification stage that operates stably without significantly changing the amplification stage configuration even when the output level is varied. There is a particular thing.
(4) 発明の構成
前述の目的を達成するための本発明の構成は、
増幅器最終段から検波回路を介し前段に信号を帰
還させて、最終段における出力変動を打ち消すよ
うに自動利得制御を行う増幅器において、前記最
終段と検波回路との間に前記最終段の出力信号レ
ベルの変化した目標値に応じて利得を変えられる
手動利得可変手段を挿入し、前記検波回路への前
記変化した目標値に対応する入力レベルは変化さ
せないことである。(4) Structure of the invention The structure of the present invention to achieve the above object is as follows:
In an amplifier that performs automatic gain control by feeding back a signal from the final stage of the amplifier to the previous stage via a detection circuit and canceling output fluctuations in the final stage, the output signal level of the final stage is set between the final stage and the detection circuit. A manual gain variable means that can change the gain according to the changed target value is inserted, and the input level corresponding to the changed target value to the detection circuit is not changed.
(5) 発明の実施例
第３図は本発明の一実施例の構成を示すブロツ
ク図である。第１図と同一符号は同様のものを示
している。第３図においてAMP６は演算増幅器
のように帰還回路を内蔵する増幅器で、検波回路
DTへの印加信号を増幅するように出力段増幅器
AMP５と検波回路との間に挿入したものである。
RVは可変抵抗器で、増幅器AMP６への入力信
号振幅を変化させる。今、出力端子OUTの出力
レベルの設定値を従前と違つた設定値として利得
制御増幅器を調整するときは、増幅器AMP６の
出力を一定にしたままで行うようにする。即ち、
増幅器AMP６の固定された増幅利得は変化させ
られないので、増幅器AMP６の入力側可変抵抗
器RVを調節することで増幅器AMP６の出力レ
ベルの一定化が出来る。従来の構成では、出力レ
ベルの設定値を変えると、検波回路に入力される
レベルも設定値に応じて変化するので、検波回路
内のダイオードの特性も変化してしまうから、充
分な制御が行えなくなつてしまう。しかし、本発
明により検波回路への入力を一定化できるから、
検波回路を構成するダイオードの特性を良好に保
つための基準電圧の再調整は必要がない。このよ
うにして最終増幅段AMP５の出力における振幅
変動に対しては、従来と同じく検波回路DTを介
して帰還させ、利得制御を行うことができ、その
動作は安定である。(5) Embodiment of the invention FIG. 3 is a block diagram showing the configuration of an embodiment of the invention. The same reference numerals as in FIG. 1 indicate similar parts. In Figure 3, AMP6 is an amplifier with a built-in feedback circuit like an operational amplifier, and a detection circuit.
Output stage amplifier to amplify the applied signal to DT
It is inserted between AMP5 and the detection circuit.
RV is a variable resistor that changes the amplitude of the input signal to the amplifier AMP6. Now, when adjusting the gain control amplifier by changing the setting value of the output level of the output terminal OUT to a different setting value than before, do so while keeping the output of the amplifier AMP6 constant. That is,
Since the fixed amplification gain of the amplifier AMP6 cannot be changed, the output level of the amplifier AMP6 can be made constant by adjusting the input variable resistor RV of the amplifier AMP6. In conventional configurations, when the output level setting value is changed, the level input to the detection circuit also changes according to the setting value, and the characteristics of the diode in the detection circuit also change, so sufficient control cannot be achieved. It will disappear. However, because the present invention allows the input to the detection circuit to be constant,
There is no need to readjust the reference voltage in order to maintain good characteristics of the diodes constituting the detection circuit. In this way, amplitude fluctuations in the output of the final amplification stage AMP5 can be fed back via the detection circuit DT and gain control can be performed as in the conventional case, and the operation is stable.
次に検波回路にダイオードを使用したとき、本
発明の構成によると、最終出力レベル即ち検波回
路への入力レベルを比較的大きい値に設定すれ
ば、ダイオードの周辺温度に対する影響が小さく
なるという作用効果があるため、以下に説明す
る。第２図に示すようにダイオードの電圧Ｖ対電
流Ｉの特性は、略二乗曲線になつているが、この
特性曲線は温度上昇のとき左方の１点鎖線のよう
に、下降のとき右方の破線のように動く傾向があ
る。そのため増幅器への入力信号振幅・増幅利得
が変化しないときであつても、検波回路を構成す
るダイオードの周辺温度が高くなると、恰も出力
レベルが上昇したように検波回路からの電流が多
く出力され、その出力により自動利得制御される
欠点があつた。ダイオードに対する入力電圧の大
小に対し、温度変化による影響を見ると、当初に
入力電圧が大きいとき所定の温度変化に基づく影
響は、当初に入力電圧が小さいとき同じ温度変化
に基づく影響と比較し、比率が小さいことが第２
図から読取れる。即ち、検波回路への入力レベル
を比較的大きい値に設定して、本発明によりその
値に固定すれば、温度変化に対しても安定な自動
利得制御の動作が得られる。 Next, when a diode is used in the detection circuit, according to the configuration of the present invention, if the final output level, that is, the input level to the detection circuit is set to a relatively large value, the effect of the diode on the ambient temperature is reduced. Since there is, it will be explained below. As shown in Figure 2, the characteristic of the voltage V vs. current I of the diode is approximately a square curve, and when the temperature rises, this characteristic curve shows a dotted line on the left, and when the temperature falls, it changes to the right. It tends to move as shown by the dashed line. Therefore, even when the input signal amplitude and amplification gain to the amplifier do not change, when the temperature around the diodes that make up the detection circuit rises, a large amount of current is output from the detection circuit, as if the output level has increased. The drawback was that the gain was automatically controlled based on the output. Looking at the effect of temperature change on the magnitude of the input voltage to the diode, when the input voltage is initially large, the effect based on a given temperature change is compared to the effect based on the same temperature change when the input voltage is initially small, The second reason is that the ratio is small.
It can be read from the figure. That is, by setting the input level to the detection circuit to a relatively large value and fixing it at that value according to the present invention, stable automatic gain control operation can be obtained even with temperature changes.
(6) 発明の効果
このようにして本発明によると、検波回路の動
作が安定化できるから、自動利得制御増幅器出力
レベルを大小異なるレベルに設定するときも、自
動利得制御の動作が良好となる。また増幅器を共
通化して使用することができる、装置が安価とな
る効果を有する。(6) Effects of the Invention In this way, according to the present invention, the operation of the detection circuit can be stabilized, so even when the output level of the automatic gain control amplifier is set to different levels, the operation of the automatic gain control is good. . In addition, it is possible to use a common amplifier, which has the effect of making the device cheaper.
第１図は従来の自動利得制御増幅段の構成を示
す図、第２図は第１図中検波回路のダイオード特
性を説明する図、第３図は本発明の一実施例の構
成を示すブロツク図である。
AMP１〜AMP５…信号増幅段、ATT１〜
ATT４…可変減衰器、DT…検波回路、DCA…
直流増幅器、CTL…制御回路、AMP６…利得制
御される増幅器、RV…可変抵抗器。
FIG. 1 is a diagram showing the configuration of a conventional automatic gain control amplifier stage, FIG. 2 is a diagram explaining the diode characteristics of the detection circuit in FIG. 1, and FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention. It is a diagram. AMP1~AMP5...Signal amplification stage, ATT1~
ATT4...variable attenuator, DT...detection circuit, DCA...
DC amplifier, CTL...control circuit, AMP6...gain controlled amplifier, RV...variable resistor.
Claims (1)
を帰還させて、最終段における出力変動を打ち消
すように自動利得制御を行う増幅器において、 前記最終段と検波回路との間に前記最終段の出
力信号レベルの変化した目標値に応じて利得を変
えられる手動利得可変手段を挿入し、前記検波回
路への前記変化した目標値に対応する入力レベル
は変化させないこと を特徴とする自動利得制御増幅器。[Scope of Claims] 1. In an amplifier that performs automatic gain control by feeding back a signal from the final stage of the amplifier to the previous stage via a detection circuit and canceling output fluctuations in the final stage, between the final stage and the detection circuit: A manual gain variable means is inserted that can change the gain according to the changed target value of the output signal level of the final stage, and the input level corresponding to the changed target value to the detection circuit is not changed. Automatic gain control amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12565683A JPS6018011A (en) | 1983-07-11 | 1983-07-11 | Automatic gain control amplifying stage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12565683A JPS6018011A (en) | 1983-07-11 | 1983-07-11 | Automatic gain control amplifying stage |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6018011A JPS6018011A (en) | 1985-01-30 |
| JPH0421364B2 true JPH0421364B2 (en) | 1992-04-09 |
Family
ID=14915406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12565683A Granted JPS6018011A (en) | 1983-07-11 | 1983-07-11 | Automatic gain control amplifying stage |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6018011A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08228116A (en) * | 1994-11-30 | 1996-09-03 | Nec Corp | Level control circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53116056A (en) * | 1977-03-18 | 1978-10-11 | Nec Corp | Automatic cain control circuit |
-
1983
- 1983-07-11 JP JP12565683A patent/JPS6018011A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53116056A (en) * | 1977-03-18 | 1978-10-11 | Nec Corp | Automatic cain control circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6018011A (en) | 1985-01-30 |
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