JPH07283673A - Automatic gain control circuit - Google Patents

Automatic gain control circuit

Info

Publication number
JPH07283673A
JPH07283673A JP6932894A JP6932894A JPH07283673A JP H07283673 A JPH07283673 A JP H07283673A JP 6932894 A JP6932894 A JP 6932894A JP 6932894 A JP6932894 A JP 6932894A JP H07283673 A JPH07283673 A JP H07283673A
Authority
JP
Japan
Prior art keywords
signal
manual
gain control
automatic gain
amplifier
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.)
Granted
Application number
JP6932894A
Other languages
Japanese (ja)
Other versions
JP2858535B2 (en
Inventor
Toyoe Yamazaki
豊栄 山崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
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 NEC Corp filed Critical NEC Corp
Priority to JP6069328A priority Critical patent/JP2858535B2/en
Publication of JPH07283673A publication Critical patent/JPH07283673A/en
Application granted granted Critical
Publication of JP2858535B2 publication Critical patent/JP2858535B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PURPOSE:To obtain an automatic gain control circuit which is capable of preventing the rapid change of a high frequency output signal at the time of switching an automatic gain control state and a manual gain control state. CONSTITUTION:A switch 5e which is provided as the constitution of an integrator 5 between the output side of a local amplifier 5a and a capacitor 5c and is possible to input the manual signal according to a manual set value in place of an internal signal integrates the amplifier signal where the difference voltage signal from a comparator 4 is amplified by a local amplifier 5a in an automtic mode via a switch terminal alpha and transmits the signal as an attenuation amount control signal to a variable attenuator 1. In a manual mode, the switch Me integrates the manual signal inputted from a manual setting terminal Hc via a switch terminal beta and transmits the signal as a manual attenuation amount control signal to the variable attenuator 1. As a result, the amplitude of the high frequency output signal outputted from an amplifier 2 amplifying the attenuation high frequency signal from the variable attenuator 1 gently changes at the time of switching an automatic control state and a manual control state.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、自動利得制御(AG
C)状態とマニュアル利得制御状態との切り替え機能を
有する自動利得制御回路に関する。
BACKGROUND OF THE INVENTION The present invention relates to an automatic gain control (AG
C) An automatic gain control circuit having a function of switching between a state and a manual gain control state.

【0002】[0002]

【従来の技術】従来、この種の自動利得制御回路には、
例えば図2に示すような構成のものがある。この自動利
得制御回路は、入力端子Inから入力される高周波信号
を後述する減衰量制御信号を参照して減衰して減衰高周
波信号を出力する可変減衰器1と、減衰高周波信号を増
幅して高周波出力信号を出力し、この高周波出力信号を
出力端子Outへ送出する増幅器2と、高周波出力信号
を検波した検波出力信号を出力する検波器3と、検波出
力信号の電圧と電圧印加端子Vdから印加される基準電
圧とを比較し,これらの両電圧の差を表わす差電圧信号
を出力する比較器4と、この差電圧信号を積分した積分
信号を減衰量制御信号として可変減衰器1へ出力する積
分器50と、積分器50からの減衰量制御信号及びマニ
ュアル設定端子Mcから入力されるマニュアル設定値に
対応したマニュアル減衰量制御信号を切り替えるスイッ
チ6とから成っている。
2. Description of the Related Art Conventionally, automatic gain control circuits of this type are
For example, there is a configuration as shown in FIG. This automatic gain control circuit includes a variable attenuator 1 for attenuating a high frequency signal input from an input terminal In with reference to an attenuation amount control signal to be described later and outputting an attenuated high frequency signal, and a high frequency signal for amplifying the attenuated high frequency signal. An amplifier 2 that outputs an output signal and sends the high-frequency output signal to the output terminal Out, a detector 3 that outputs a detection output signal that detects the high-frequency output signal, and a voltage of the detection output signal and a voltage applied from the voltage application terminal Vd A reference voltage that is generated and outputs a difference voltage signal representing the difference between the two voltages, and an integrated signal obtained by integrating the difference voltage signal is output to the variable attenuator 1 as an attenuation amount control signal. An integrator 50 and a switch 6 for switching between the attenuation amount control signal from the integrator 50 and the manual attenuation amount control signal corresponding to the manual setting value input from the manual setting terminal Mc. It consists et al.

【0003】このうち、積分器50は入力正極端子が接
地され,差電圧信号を増幅する局部増幅器50aと、こ
の局部増幅器50aの入力負極端子及び比較器4の間に
介在された抵抗50bと、局部増幅器50aの出力端子
及び入力負極端子の間に介在され,局部増幅器50aと
並列接続されたコンデンサ50cとによって構成されて
いる。
Of these, the integrator 50 has an input positive terminal grounded and a local amplifier 50a for amplifying a differential voltage signal, and a resistor 50b interposed between the input negative terminal of the local amplifier 50a and the comparator 4. The local amplifier 50a is provided between the output terminal and the input negative electrode terminal, and is constituted by the local amplifier 50a and a capacitor 50c connected in parallel.

【0004】この自動利得制御回路において、高周波出
力信号の振幅を目標値へと自動的に制御する自動・モー
ドの場合、高周波信号が可変減衰器1を通って減衰高周
波信号となり、増幅器2で増幅されることで高周波出力
信号(回路全体の出力信号)となるが、この高周波出力
信号の一部は検波器3で検波されて検波出力信号となっ
た後、比較器4に加えられる。比較器4では検波出力信
号の電圧と基準電圧とを比較し、各電圧の差を表わす差
電圧信号を出力する。局部増幅器50aでは差電圧信号
を増幅した増幅信号を出力し、この増幅信号がコンデン
サ50cの接続部を通って積分されることで得られる積
分信号を減衰量制御信号としてスイッチ6の切り替え端
子αへ送出する。減衰量制御信号は切り替え端子αを介
して可変減衰器1に入力される。これにより、可変減衰
器1の減衰量が制御され、増幅器2から出力される高周
波出力信号の振幅は一定となるように制御されるため、
自動利得制御機能が得られる。
In this automatic gain control circuit, in the automatic mode in which the amplitude of the high frequency output signal is automatically controlled to the target value, the high frequency signal passes through the variable attenuator 1 to become the attenuated high frequency signal and is amplified by the amplifier 2. As a result, the high-frequency output signal (the output signal of the entire circuit) is obtained. A part of this high-frequency output signal is detected by the detector 3 to become a detection output signal, which is then added to the comparator 4. The comparator 4 compares the voltage of the detection output signal with the reference voltage and outputs a difference voltage signal representing the difference between the voltages. The local amplifier 50a outputs an amplified signal obtained by amplifying the differential voltage signal, and the integrated signal obtained by integrating the amplified signal through the connecting portion of the capacitor 50c is used as an attenuation amount control signal to the switching terminal α of the switch 6. Send out. The attenuation amount control signal is input to the variable attenuator 1 via the switching terminal α. As a result, the amount of attenuation of the variable attenuator 1 is controlled and the amplitude of the high frequency output signal output from the amplifier 2 is controlled to be constant.
An automatic gain control function is obtained.

【0005】一方、この自動利得制御回路において、高
周波出力信号の振幅を目標値へと手動で設定するマニュ
アル・モードの場合、スイッチ6の切り替え端子βを介
してマニュアル減衰量制御信号を可変減衰器1へ送出す
れば良く、この場合にも可変減衰器1の減衰量が制御さ
れ、増幅器2からの高周波出力信号の振幅を一定となる
ように制御できる。
On the other hand, in the automatic gain control circuit, in the manual mode in which the amplitude of the high frequency output signal is manually set to the target value, the manual attenuation amount control signal is supplied to the variable attenuator via the switching terminal β of the switch 6. It is sufficient to send the signal to the variable attenuator 1, and in this case as well, the attenuation amount of the variable attenuator 1 is controlled, and the amplitude of the high frequency output signal from the amplifier 2 can be controlled to be constant.

【0006】因みに、こうした自動利得制御に関連する
技術は、例えば特開平4−330811号公報等に開示
されている。
Incidentally, a technique related to such automatic gain control is disclosed in, for example, Japanese Patent Laid-Open No. 4-330811.

【0007】[0007]

【発明が解決しようとする課題】上述した自動利得制御
状態とマニュアル状態との切り替え機能を有する自動利
得制御回路の場合、各状態の切り替え時に以下に説明す
る多くの問題がある。
In the case of the above-mentioned automatic gain control circuit having a function of switching between the automatic gain control state and the manual state, there are many problems described below when switching between the states.

【0008】先ず、自動・モードからマニュアル・モー
ドへの切り替え時には、可変減衰器1に対する減衰量制
御信号がスイッチ6において切り替え端子αから切り替
え端子βへと切り替えられるとき、増幅器2からの高周
波出力信号の振幅がステップ状に変化してしまう。こう
した場合、自動利得制御回路でデータ伝送を行うと、目
標値とマニュアル設定値との差が大きければこれに伴っ
て振幅のステップ変化も急峻となって高周波出力信号の
波形が乱れて伝送データに悪影響を及ぼすため、これを
使用する回線にエラー等を発生させる原因となってしま
う。
First, when switching from the automatic mode to the manual mode, when the attenuation control signal for the variable attenuator 1 is switched in the switch 6 from the switching terminal α to the switching terminal β, the high frequency output signal from the amplifier 2 The amplitude of changes in steps. In such a case, when data is transmitted by the automatic gain control circuit, if the difference between the target value and the manual setting value is large, the step change of the amplitude becomes steep accordingly, and the waveform of the high-frequency output signal is disturbed, resulting in transmission data. Since it has an adverse effect, it may cause an error or the like in a line using this.

【0009】又、マニュアル・モードから自動モードへ
の切り替え時には、マニュアル設定値に従って設定され
ている高周波出力信号の振幅が目標値と異なると、比較
器4で出力される差電圧信号が積分器50で積分されて
増大することになる。
Further, when switching from the manual mode to the automatic mode, if the amplitude of the high frequency output signal set according to the manually set value is different from the target value, the difference voltage signal output from the comparator 4 becomes the integrator 50. Will be integrated and increased.

【0010】このとき、マニュアル設定値<目標値であ
ると、比較器4からの差電圧信号は高周波出力信号の振
幅を上げる方向の電圧となり、この電圧を積分した積分
器50からの減衰量制御信号は可変減衰器1の減衰量を
最小とする制御電圧となる。このような状態でマニュア
ル・モードから自動・モードへ切り替える(復帰させ
る)と、瞬時に可変減衰器1の減衰量が最小となり、増
幅器2からの高周波出力信号の振幅が最大となる。従っ
て、増幅器2からの高周波出力信号の振幅がマニュアル
設定値→最大値→目標値への引き込みと急激に変化する
ため、データ伝送を行うと、使用する回線にエラー等を
発生させる原因となってしまう。
At this time, if the manually set value <the target value, the difference voltage signal from the comparator 4 becomes a voltage in the direction of increasing the amplitude of the high frequency output signal, and the attenuation amount control from the integrator 50 that integrates this voltage is performed. The signal becomes a control voltage that minimizes the amount of attenuation of the variable attenuator 1. When the manual mode is switched (reset) to the automatic mode in such a state, the amount of attenuation of the variable attenuator 1 instantly becomes the minimum and the amplitude of the high frequency output signal from the amplifier 2 becomes the maximum. Therefore, the amplitude of the high-frequency output signal from the amplifier 2 rapidly changes from the manually set value to the maximum value to the target value, so that data transmission causes an error in the line used. I will end up.

【0011】更に、マニュアル設定値>目標値である場
合も同様に、増幅器2からの高周波出力信号の振幅がマ
ニュアル設定値→最小値→目標値への引き込みと急激に
変化し、データ伝送を行うと伝送データに悪影響を及ぼ
すため、使用する回線にエラー等を発生させる原因とな
ってしまう。
Further, also when the manual set value> the target value, similarly, the amplitude of the high frequency output signal from the amplifier 2 suddenly changes as the manual set value → the minimum value → the target value is pulled, and data transmission is performed. Since it adversely affects the transmission data, it causes an error in the line used.

【0012】本発明は、かかる問題を解決すべくなされ
たもので、その技術的課題は、自動利得制御状態とマニ
ュアル利得制御状態との切り替え時における高周波出力
信号の急激な変化を防止し得る自動利得制御回路を提供
することにある。
The present invention has been made to solve such a problem, and its technical problem is to prevent an abrupt change in a high frequency output signal when switching between an automatic gain control state and a manual gain control state. It is to provide a gain control circuit.

【0013】[0013]

【課題を解決するための手段】本発明によれば、入力さ
れる高周波信号を減衰量制御信号を参照して減衰して減
衰高周波信号を出力する可変減衰器と、減衰高周波信号
を増幅して高周波出力信号を出力する増幅器と、高周波
出力信号を検波して検波出力信号を出力する検波器と、
検波出力信号の電圧と基準電圧とを比較し,該両電圧の
差を表わす差電圧信号を出力する比較器と、差電圧信号
を積分して積分信号を生成し,該積分信号を減衰量制御
信号として可変減衰器へ送出する積分器とを含み、積分
器は、内部信号の代わりにマニュアル設定値に応じたマ
ニュアル信号を入力可能な切り替え手段を有する自動利
得制御回路が得られる。
According to the present invention, a variable attenuator for attenuating an input high frequency signal with reference to an attenuation amount control signal to output an attenuated high frequency signal, and an amplifier for amplifying the attenuated high frequency signal are provided. An amplifier that outputs a high-frequency output signal, a detector that detects the high-frequency output signal and outputs a detection output signal,
A comparator that compares the voltage of the detection output signal with the reference voltage and outputs a difference voltage signal that represents the difference between the two voltages, and a comparator that integrates the difference voltage signal to generate an integral signal and controls the attenuation amount of the integral signal. An automatic gain control circuit including a switching means capable of inputting a manual signal according to a manual set value instead of the internal signal is obtained.

【0014】又、本発明によれば、上記自動利得制御回
路において、積分器は、差電圧信号を増幅する局部増幅
手段と、局部増幅手段に並列接続された帰還容量素子と
を含み、切り替え手段は局部増幅手段の出力側及び帰還
容量素子の間に設けられた自動利得制御回路が得られ
る。
According to the present invention, in the above automatic gain control circuit, the integrator includes a local amplifying means for amplifying the differential voltage signal and a feedback capacitance element connected in parallel with the local amplifying means, and the switching means. An automatic gain control circuit provided between the output side of the local amplification means and the feedback capacitance element can be obtained.

【0015】[0015]

【実施例】以下に実施例を挙げ、本発明の自動利得制御
回路について、図面を参照して詳細に説明する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic gain control circuit according to the present invention will be described in detail below with reference to the accompanying drawings.

【0016】図1は、本発明の一実施例に係る自動利得
制御回路の基本構成を示したものである。但し、この自
動利得制御回路も図2に示した自動利得制御回路と同様
な構成部分を有しているので、同一部分には同じ符号を
付して説明を省略する。
FIG. 1 shows a basic configuration of an automatic gain control circuit according to an embodiment of the present invention. However, since this automatic gain control circuit also has the same components as the automatic gain control circuit shown in FIG. 2, the same parts are designated by the same reference numerals and the description thereof will be omitted.

【0017】この自動利得制御回路では、積分器5が差
電圧信号を増幅する局部増幅手段としての局部増幅器5
aと、この局部増幅器5aの入力負極端子及び比較器4
の間に介在された抵抗5bと、局部増幅器5aの出力側
及びコンデンサ5cの間に設けられ,内部信号の代わり
にマニュアル設定値に応じたマニュアル信号を入力可能
な切り替え手段としてのスイッチ5eとから成ってい
る。因みに、スイッチ5eは切り替え端子α,βを有
し、切り替え端子βとマニュアル設定端子Mcとの間に
は抵抗5dが設けられている。又、ここでも局部増幅器
5aの入力正極端子は接地されている。
In this automatic gain control circuit, the integrator 5 serves as a local amplifying means for amplifying the difference voltage signal.
a, the negative input terminal of the local amplifier 5a and the comparator 4
A resistor 5b interposed between the switch 5e and a switch 5e provided between the output side of the local amplifier 5a and the capacitor 5c and capable of inputting a manual signal according to a manual set value instead of the internal signal. Made of Incidentally, the switch 5e has switching terminals α and β, and a resistor 5d is provided between the switching terminal β and the manual setting terminal Mc. Also here, the input positive terminal of the local amplifier 5a is grounded.

【0018】積分器5は、比較器4からの差電圧信号を
積分した積分信号を減衰量制御信号として出力し、この
減衰量制御信号を可変減衰器1へ送出するが、このとき
にスイッチ5eは、減衰量制御信号の前段(積分前)と
なる差電圧信号を増幅した増幅信号と、マニュアル設定
値に対応したマニュアル減衰量制御信号の前段(積分
前)となるマニュアル信号とを入力し,各信号をそれぞ
れ自動利得制御時とマニュアル利得制御時とで切り替え
る。
The integrator 5 outputs an integrated signal obtained by integrating the difference voltage signal from the comparator 4 as an attenuation amount control signal and sends this attenuation amount control signal to the variable attenuator 1. At this time, the switch 5e. Input the amplified signal obtained by amplifying the differential voltage signal that is the previous stage (before integration) of the attenuation control signal and the manual signal that is the previous stage (before integration) of the manual attenuation control signal corresponding to the manual setting value. Each signal is switched between automatic gain control and manual gain control.

【0019】即ち、スイッチ5eは、高周波出力信号の
振幅を目標値へと自動的に制御する自動・モードの場
合、差電圧信号を局部増幅器5aにより増幅した増幅信
号を切り替え端子αを介して積分し、この積分信号を減
衰量制御信号とした上で可変減衰器1へ送出するが、高
周波出力信号の振幅を目標値へと手動で設定するマニュ
アル・モードの場合、マニュアル設定端子Mcから入力
されるマニュアル設定値に対応したマニュアル信号を切
り替え端子βを介して積分し、この積分信号をマニュア
ル減衰量制御信号とした上で可変減衰器1へ送出する。
That is, when the switch 5e is in the automatic mode for automatically controlling the amplitude of the high frequency output signal to the target value, the amplified signal obtained by amplifying the differential voltage signal by the local amplifier 5a is integrated via the switching terminal α. Then, this integrated signal is sent to the variable attenuator 1 after being used as the attenuation amount control signal, but in the manual mode in which the amplitude of the high frequency output signal is manually set to the target value, it is input from the manual setting terminal Mc. The manual signal corresponding to the manual set value is integrated via the switching terminal β, and the integrated signal is sent to the variable attenuator 1 after being used as a manual attenuation amount control signal.

【0020】次に、この自動利得制御回路の動作を説明
する。先ず、高周波出力信号の振幅を目標値へと自動的
に制御する自動・モードの場合、高周波信号が可変減衰
器1を通って減衰高周波信号となり、増幅器2で増幅さ
れることで高周波出力信号(回路全体の出力信号)とな
るが、この高周波出力信号の一部は検波器3で検波され
て検波出力信号となった後、比較器4に加えられる。比
較器4では検波出力信号の電圧と基準電圧とを比較し、
両電圧の差を表わす差電圧信号を出力し、積分器5では
差電圧信号を増幅した増幅信号をスイッチ5eの切り替
え端子αを介して積分し,減衰量制御信号とした上で可
変減衰器1へ送出する。これにより、可変減衰器1の減
衰量が制御され、増幅器2から出力される高周波出力信
号の振幅は一定となるように制御されるため、自動利得
制御機能が得られる。
Next, the operation of this automatic gain control circuit will be described. First, in the case of the automatic mode in which the amplitude of the high frequency output signal is automatically controlled to the target value, the high frequency signal passes through the variable attenuator 1 to become the attenuated high frequency signal and is amplified by the amplifier 2 so that the high frequency output signal ( The output signal of the entire circuit), and a part of this high-frequency output signal is detected by the wave detector 3 to become a wave detection output signal, and then added to the comparator 4. The comparator 4 compares the voltage of the detection output signal with the reference voltage,
The variable attenuator 1 outputs a differential voltage signal representing the difference between the two voltages, and the integrator 5 integrates the amplified signal obtained by amplifying the differential voltage signal via the switching terminal α of the switch 5e to obtain an attenuation amount control signal and then the variable attenuator 1 Send to. As a result, the attenuation amount of the variable attenuator 1 is controlled and the amplitude of the high frequency output signal output from the amplifier 2 is controlled to be constant, so that the automatic gain control function is obtained.

【0021】一方、高周波出力信号の振幅を目標値へと
手動で設定するマニュアル・モードの場合、スイッチ5
eの切り替え端子βを介してマニュアル信号を積分し,
マニュアル減衰量制御信号とした上で可変減衰器1へ送
出すれば良く、この場合にも可変減衰器1の減衰量が制
御され、増幅器2からの高周波出力信号の振幅を一定と
なるように制御される。
On the other hand, in the manual mode in which the amplitude of the high frequency output signal is manually set to the target value, the switch 5
The manual signal is integrated via the switching terminal β of e,
A manual attenuation amount control signal may be sent to the variable attenuator 1, and the attenuation amount of the variable attenuator 1 is controlled in this case as well, and the amplitude of the high frequency output signal from the amplifier 2 is controlled to be constant. To be done.

【0022】ところで、この自動利得制御回路の場合、
スイッチ5eの接続を局部増幅器5aより出力される増
幅信号からマニュアル設定値によるマニュアル信号へ切
り替えるとき,即ち、自動・モードからマニュアル・モ
ードへ変更を行うと、切り替えの瞬間には積分器5を構
成するコンデンサ5cにチャージアップされた電圧が残
留しており、この残留電圧が可変減衰器1に加わり、こ
の後は抵抗5d及びコンデンサ5cの時定数で決まる速
さで充電,又は放電され、最終的にマニュアル設定値に
対応するマニュアル減衰量制御信号が可変減衰器1へ伝
送される。従って、増幅器2からの高周波出力信号の振
幅は目標値から緩やかにマニュアル設定値へと到達す
る。
By the way, in the case of this automatic gain control circuit,
When the connection of the switch 5e is switched from the amplified signal output from the local amplifier 5a to the manual signal according to the manual setting value, that is, when the automatic mode is changed to the manual mode, the integrator 5 is configured at the moment of switching. The voltage charged up in the capacitor 5c that remains is applied, and this residual voltage is applied to the variable attenuator 1, after which it is charged or discharged at a speed determined by the time constant of the resistor 5d and the capacitor 5c, and finally A manual attenuation amount control signal corresponding to the manual set value is transmitted to the variable attenuator 1. Therefore, the amplitude of the high frequency output signal from the amplifier 2 gently reaches the manual set value from the target value.

【0023】又、マニュアル・モードから自動・モード
へ変更を行うと、同様に切り替えの瞬間にはコンデンサ
5cにマニュアル設定時における電圧が残留しており、
この残留電圧が可変減衰器1に加わり、この後は自動利
得制御回路全体のループの応答速度で充電,又は放電さ
れ、最終的に目標値の電圧に対応する減衰量制御信号が
可変減衰器1へ伝送される。従って、増幅器2の高周波
出力信号の振幅はマニュアル設定値から緩やかに目標値
へと到達する。
When the manual mode is changed to the automatic mode, the voltage at the time of manual setting remains in the capacitor 5c at the moment of switching, similarly,
This residual voltage is applied to the variable attenuator 1, and thereafter, it is charged or discharged at the response speed of the loop of the entire automatic gain control circuit, and finally the attenuation control signal corresponding to the target voltage is output to the variable attenuator 1. Transmitted to. Therefore, the amplitude of the high frequency output signal of the amplifier 2 gradually reaches the target value from the manually set value.

【0024】即ち、この自動利得制御回路においては、
自動利得制御状態とマニュアル利得制御状態との切り替
え時の応答が指数関数的に緩やかになる。
That is, in this automatic gain control circuit,
The response at the time of switching between the automatic gain control state and the manual gain control state becomes exponentially gentle.

【0025】[0025]

【発明の効果】以上に説明したように、本発明の自動利
得制御回路によれば、自動利得制御状態とマニュアル利
得制御状態との切り替え時に、増幅器からの高周波出力
信号の振幅が急峻に変化されず、その応答が指数関数的
に緩やかになるので、従来のように最大値や最小値に飛
ぶ現象を生じることなく安定して切り替えを行うことが
できるようになる。特に、この自動利得制御回路の場
合、積分器の構成を局部増幅手段の出力側及び帰還容量
素子の間に内部信号の代わりにマニュアル設定値に応じ
たマニュアル信号を入力可能なものとし,積分前に切り
替えを行い得るようにしているので、自動・モードから
マニュアル・モードへの切り替え時には高周波出力信号
の振幅の変化が抵抗及び帰還容量素子で決まる時定数の
速さで緩やかに応答し、マニュアル・モードから自動モ
ードへの切り替え時にも自動利得制御回路全体のループ
応答で決まる速さで緩やかに応答するようになる。従っ
て、この自動利得制御回路によりデータ伝送を行うと伝
送データに悪影響を及ぼすことが無くなり、使用時の信
頼性が向上する。
As described above, according to the automatic gain control circuit of the present invention, the amplitude of the high frequency output signal from the amplifier is sharply changed when switching between the automatic gain control state and the manual gain control state. Instead, the response becomes exponentially gradual, so that stable switching can be performed without causing the phenomenon of jumping to the maximum value or the minimum value as in the conventional case. In particular, in the case of this automatic gain control circuit, the integrator is configured so that a manual signal according to the manual set value can be input instead of the internal signal between the output side of the local amplification means and the feedback capacitance element. Since it is possible to switch to the manual mode, the change in the amplitude of the high frequency output signal responds slowly at the speed of the time constant determined by the resistance and the feedback capacitance element. Even when the mode is switched to the automatic mode, the automatic gain control circuit responds slowly at a speed determined by the loop response of the entire circuit. Therefore, when data is transmitted by this automatic gain control circuit, the transmitted data is not adversely affected, and the reliability in use is improved.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例に係る自動利得制御回路の基
本構成を示したものである。
FIG. 1 shows a basic configuration of an automatic gain control circuit according to an embodiment of the present invention.

【図2】従来例の自動利得制御回路の基本構成を示した
ものである。
FIG. 2 shows a basic configuration of an automatic gain control circuit of a conventional example.

【符号の説明】[Explanation of symbols]

1 可変減衰器 2 増幅器 3 検波器 4 比較器 5,50 積分器 5a,50a 局部増幅器 5b,5d,50b 抵抗 5c,50c コンデンサ 5e,6 スイッチ 1 Variable Attenuator 2 Amplifier 3 Detector 4 Comparator 5,50 Integrator 5a, 50a Local Amplifier 5b, 5d, 50b Resistor 5c, 50c Capacitor 5e, 6 Switch

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 入力される高周波信号を減衰量制御信号
を参照して減衰して減衰高周波信号を出力する可変減衰
器と、前記減衰高周波信号を増幅して高周波出力信号を
出力する増幅器と、前記高周波出力信号を検波して検波
出力信号を出力する検波器と、前記検波出力信号の電圧
と基準電圧とを比較し,該両電圧の差を表わす差電圧信
号を出力する比較器と、前記差電圧信号を積分して積分
信号を生成し,該積分信号を前記減衰量制御信号として
前記可変減衰器へ送出する積分器とを含み、前記積分器
は、内部信号の代わりにマニュアル設定値に応じたマニ
ュアル信号を入力可能な切り替え手段を有することを特
徴とする自動利得制御回路。
1. A variable attenuator for attenuating an input high frequency signal with reference to an attenuation amount control signal to output an attenuated high frequency signal, and an amplifier for amplifying the attenuated high frequency signal and outputting a high frequency output signal. A detector that detects the high-frequency output signal and outputs a detection output signal; a comparator that compares the voltage of the detection output signal with a reference voltage and outputs a difference voltage signal that represents the difference between the two voltages; And an integrator that generates an integrated signal by integrating the difference voltage signal and sends the integrated signal to the variable attenuator as the attenuation amount control signal, wherein the integrator is set to a manually set value instead of an internal signal. An automatic gain control circuit having a switching means capable of inputting a corresponding manual signal.
【請求項2】 請求項1記載の自動利得制御回路におい
て、前記積分器は、前記差電圧信号を増幅する局部増幅
手段と、前記局部増幅手段に並列接続された帰還容量素
子とを含み、前記切り替え手段は前記局部増幅手段の出
力側及び前記帰還容量素子の間に設けられたことを特徴
とする自動利得制御回路。
2. The automatic gain control circuit according to claim 1, wherein the integrator includes a local amplification means for amplifying the differential voltage signal, and a feedback capacitance element connected in parallel to the local amplification means, The automatic gain control circuit is characterized in that the switching means is provided between the output side of the local amplification means and the feedback capacitance element.
JP6069328A 1994-04-07 1994-04-07 Automatic gain control circuit Expired - Fee Related JP2858535B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6069328A JP2858535B2 (en) 1994-04-07 1994-04-07 Automatic gain control circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6069328A JP2858535B2 (en) 1994-04-07 1994-04-07 Automatic gain control circuit

Publications (2)

Publication Number Publication Date
JPH07283673A true JPH07283673A (en) 1995-10-27
JP2858535B2 JP2858535B2 (en) 1999-02-17

Family

ID=13399381

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6069328A Expired - Fee Related JP2858535B2 (en) 1994-04-07 1994-04-07 Automatic gain control circuit

Country Status (1)

Country Link
JP (1) JP2858535B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100382733B1 (en) * 2001-02-08 2003-05-09 삼성전자주식회사 Automatic gain controller for preventing peaking and method for preventing peaking in optical disc reproducing system

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6281108A (en) * 1985-10-04 1987-04-14 Nec Corp Agc amplifier
JPH03198516A (en) * 1989-12-27 1991-08-29 Nec Corp Automatic gain control amplifier

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6281108A (en) * 1985-10-04 1987-04-14 Nec Corp Agc amplifier
JPH03198516A (en) * 1989-12-27 1991-08-29 Nec Corp Automatic gain control amplifier

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100382733B1 (en) * 2001-02-08 2003-05-09 삼성전자주식회사 Automatic gain controller for preventing peaking and method for preventing peaking in optical disc reproducing system

Also Published As

Publication number Publication date
JP2858535B2 (en) 1999-02-17

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