JPH0993204A - Optical reception circuit - Google Patents
Optical reception circuitInfo
- Publication number
- JPH0993204A JPH0993204A JP7244185A JP24418595A JPH0993204A JP H0993204 A JPH0993204 A JP H0993204A JP 7244185 A JP7244185 A JP 7244185A JP 24418595 A JP24418595 A JP 24418595A JP H0993204 A JPH0993204 A JP H0993204A
- Authority
- JP
- Japan
- Prior art keywords
- light receiving
- voltage
- receiving element
- power supply
- inductor
- 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.)
- Pending
Links
Landscapes
- Closed-Circuit Television Systems (AREA)
- Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
- Electronic Switches (AREA)
- Selective Calling Equipment (AREA)
- Optical Communication System (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ＣＡＴＶや映像監視装
置等に使用する光受信回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver circuit used for CATV, video surveillance equipment and the like.
【０００２】[0002]
【従来の技術】図２は、従来のこの種の光受信回路の要
部を示したものである。図２において、１は受光素子、
２はコンデンサ、３はプリアンプ、４は受光素子１およ
びコンデンサ２の接続点とアースとの間に接続された抵
抗である。2. Description of the Related Art FIG. 2 shows a main part of a conventional optical receiving circuit of this type. In FIG. 2, 1 is a light receiving element,
Reference numeral 2 is a capacitor, 3 is a preamplifier, and 4 is a resistor connected between a connection point of the light receiving element 1 and the capacitor 2 and the ground.
【０００３】次に、上記構成の従来例の動作を説明す
る。光信号は受光素子１に入力されると電流に変換され
る。この電流は直流成分と交流成分である信号を含んで
いる。プリアンプ３には交流成分の信号のみが入力され
るように、信号周波数の帯域では十分インピーダンスの
低いコンデンサ２を通し、直流成分をカットする。直流
成分は抵抗４を通してアースへ流れる。Next, the operation of the conventional example having the above configuration will be described. When an optical signal is input to the light receiving element 1, it is converted into a current. This current contains signals that are a direct current component and an alternating current component. In order to input only the AC component signal to the preamplifier 3, the DC component is cut through the capacitor 2 having a sufficiently low impedance in the signal frequency band. The DC component flows to the ground through the resistor 4.
【０００４】このようにして、上記従来例では、光信号
が入力すると電気信号に変換され、信号周波成分のみプ
リアンプ３で増幅され、出力される。Thus, in the above-mentioned conventional example, when an optical signal is input, it is converted into an electrical signal, and only the signal frequency component is amplified by the preamplifier 3 and output.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上記構
成の光受信回路では、入力される光信号のレベルが大き
くなると、受光素子１を流れる電流が多くなり、その結
果、抵抗４を流れる電流も多くなって抵抗４での電圧降
下が大きくなり、電源電圧が一定の場合は受光素子１の
両端に印加される電圧が小さくなる。逆に、光信号の入
力レベルが小さくなった場合、受光素子１に印加される
電圧が大きくなる。このため、電源電圧は、受光レベル
が大きくなったときでも、受光素子１に十分な電圧が印
加される電圧にしなければならない。また、受光レベル
が小さくなり、受光素子１に印加される電圧が大きくな
った場合でも、受光素子の印加電圧の定格値を越えない
ようにしなければならない。このため、受光レベルの変
化の範囲が制限される。However, in the optical receiving circuit having the above-described structure, when the level of the input optical signal increases, the current flowing through the light receiving element 1 increases, and as a result, the current flowing through the resistor 4 also increases. As a result, the voltage drop across the resistor 4 increases, and when the power supply voltage is constant, the voltage applied across the light receiving element 1 decreases. Conversely, when the input level of the optical signal decreases, the voltage applied to the light receiving element 1 increases. Therefore, the power supply voltage must be a voltage at which a sufficient voltage is applied to the light receiving element 1 even when the light receiving level becomes high. Further, even when the light receiving level becomes low and the voltage applied to the light receiving element 1 becomes high, it is necessary to prevent the applied voltage of the light receiving element from exceeding the rated value. Therefore, the range of change in the light reception level is limited.
【０００６】さらに、受光素子１で発生する歪は、受光
素子１に印加される電圧に依存し、歪が最小になる電圧
が存在する。ある受光レベルで歪が最小になるように電
源電圧を決めておいても、受光レベルが変化した場合、
その最適な電圧からずれ、歪が増加するという問題があ
った。Further, the distortion generated in the light receiving element 1 depends on the voltage applied to the light receiving element 1, and there is a voltage at which the distortion is minimized. Even if the power supply voltage is determined so that the distortion is minimized at a certain received light level, if the received light level changes,
There is a problem in that the voltage deviates from the optimum voltage and distortion increases.
【０００７】本発明は、上記従来技術の問題点を解決す
るもので、受光レベルが変化しても受光素子に印加され
る電圧が変化しないようにした光受信回路を提供するこ
とを目的とする。An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an optical receiving circuit in which the voltage applied to the light receiving element does not change even if the light receiving level changes. .
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に、本発明の光受信回路は、受光素子で光信号を光電変
換した電気信号を、コンデンサを介してプリアンプに入
力する光受信回路において、前記受光素子およびコンデ
ンサの接続点とアースとの間に、信号周波数帯域では十
分インピーダンスが大きく、直流成分に対してはインピ
ーダンスが低いインダクタを備えている構成とする。In order to achieve the above object, an optical receiving circuit of the present invention is an optical receiving circuit in which an electric signal obtained by photoelectrically converting an optical signal by a light receiving element is input to a preamplifier through a capacitor. An inductor having a sufficiently large impedance in the signal frequency band and a low impedance with respect to a DC component is provided between the connection point of the light receiving element and the capacitor and the ground.
【０００９】[0009]
【作用】上記構成によれば、受光素子から出力される信
号の直流成分をインダクタを通してアースに流すことに
より、受光レベルが変化しても、受光素子に印加される
電圧は変化しなくなる。これにより、電源電圧を低くす
ることができると共に、歪が最小になる電圧を印加した
状態を、受光レベルが変化しても維持することができ
る。According to the above structure, the DC component of the signal output from the light receiving element is passed through the inductor to the ground, so that the voltage applied to the light receiving element does not change even if the light receiving level changes. As a result, the power supply voltage can be lowered, and the state in which the voltage that minimizes distortion is applied can be maintained even if the light receiving level changes.
【００１０】[0010]
【実施例】以下、図面を参照しながら実施例を詳細に説
明する。図１は、本発明の一実施例を示したものであ
り、図２と同一のものには同一符号を付してある。即
ち、１は受光素子、２はコンデンサ、３はプリアンプ、
５は受光素子１およびコンデンサ２の接続点とアースと
の間に接続されたインダクタである。Embodiments will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which the same parts as those in FIG. 2 are designated by the same reference numerals. That is, 1 is a light receiving element, 2 is a capacitor, 3 is a preamplifier,
Reference numeral 5 is an inductor connected between the connection point of the light receiving element 1 and the capacitor 2 and the ground.
【００１１】次に、本実施例の動作を説明する。光信号
は受光素子１に入力されて電流に変換される。この電流
は直流成分と交流成分である信号を含んでおり、このう
ち直流成分はインダクタ５を通ってアースに流れる。交
流である信号成分はコンデンサ２を通り、プリアンプ３
に入力されて増幅、出力される。Next, the operation of this embodiment will be described. The optical signal is input to the light receiving element 1 and converted into a current. This current contains a signal that is a direct current component and an alternating current component, of which the direct current component flows to the ground through the inductor 5. The signal component that is an alternating current passes through the capacitor 2 and the preamplifier 3
Is input to, amplified, and output.
【００１２】ここで、受光レベルが変化しても、インダ
クタ５での電圧降下は小さいので、電源電圧そのままが
受光素子１の両端に印加される。従って、受光素子１の
動作に必要な最小電圧を電源電圧とすることができる。
また、歪が最小となる電圧を電源電圧とすれば、受光レ
ベルが変化しても受光素子１の両端の電圧は変化しない
ため、受光素子１に印加されている電圧は常に歪が最小
の電圧のままである。Since the voltage drop in the inductor 5 is small even if the light receiving level changes, the power supply voltage is applied to both ends of the light receiving element 1 as it is. Therefore, the minimum voltage required for the operation of the light receiving element 1 can be the power supply voltage.
If the voltage with the minimum distortion is set as the power supply voltage, the voltage across the light receiving element 1 does not change even if the light receiving level changes. Therefore, the voltage applied to the light receiving element 1 is always the voltage with the minimum distortion. It remains.
【００１３】[0013]
【発明の効果】以上説明したように、本発明によれば、
受光素子から出力される信号の直流成分をインダクタを
通してアースに流すことにより、受光レベルが変化して
も、受光素子に印加される電圧は変化せず、これによ
り、電源電圧を低く設定することができると共に、歪が
最小になる電圧を印加した状態を、受光レベルが変化し
ても維持することができる効果がある。As described above, according to the present invention,
By passing the DC component of the signal output from the light receiving element to the ground through the inductor, the voltage applied to the light receiving element does not change even if the light receiving level changes, which allows the power supply voltage to be set low. In addition to the effect, it is possible to maintain the state in which the voltage with which the distortion is minimized is applied even if the light receiving level changes.
【図１】本発明の一実施例の光受信器の要部構成を示す
ブロック図である。FIG. 1 is a block diagram showing a main configuration of an optical receiver according to an embodiment of the present invention.
【図２】従来の光受信器の要部構成を示すブロック図で
ある。FIG. 2 is a block diagram showing a main configuration of a conventional optical receiver.
１ … 受光素子、 ２ … コンデンサ、 ３ … プリアン
プ、 ５ … インダクタ。1 ... Light receiving element, 2 ... Capacitor, 3 ... Preamplifier, 5 ... Inductor.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０３Ｋ 17/78 Ｈ０４Ｎ 7/16 7/18 Ｈ０４Ｑ 9/00 ３０１ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Office reference number FI Technical indication location H03K 17/78 H04N 7/16 7/18 H04Q 9/00 301
Claims (1)
号を、コンデンサを介してプリアンプに入力する光受信
回路において、前記受光素子およびコンデンサの接続点
とアースとの間に、信号周波数帯域では十分インピーダ
ンスが大きく、直流成分に対してはインピーダンスが低
いインダクタを備えていることを特徴とする光受信回
路。1. In an optical receiving circuit for inputting an electric signal obtained by photoelectrically converting an optical signal by a light receiving element to a preamplifier through a capacitor, in a signal frequency band between a connection point of the light receiving element and the capacitor and ground. An optical receiving circuit comprising an inductor having a sufficiently large impedance and a low impedance for a DC component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7244185A JPH0993204A (en) | 1995-09-22 | 1995-09-22 | Optical reception circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7244185A JPH0993204A (en) | 1995-09-22 | 1995-09-22 | Optical reception circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0993204A true JPH0993204A (en) | 1997-04-04 |
Family
ID=17115040
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7244185A Pending JPH0993204A (en) | 1995-09-22 | 1995-09-22 | Optical reception circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0993204A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002045255A1 (en) * | 2000-12-01 | 2002-06-06 | Transmode Systems Ab | Amplifier circuit, an optical communication system and a method of controlling amplification |
| WO2002045300A1 (en) * | 2000-12-01 | 2002-06-06 | Transmode Systems Ab | A transmitter-receiver device and a communication system |
| KR20040050948A (en) * | 2002-12-11 | 2004-06-18 | 한국전자통신연구원 | High speed optoelectronics modules compensated with induction |
| WO2008099507A1 (en) * | 2007-02-16 | 2008-08-21 | Fujitsu Limited | Light receiver |
-
1995
- 1995-09-22 JP JP7244185A patent/JPH0993204A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002045255A1 (en) * | 2000-12-01 | 2002-06-06 | Transmode Systems Ab | Amplifier circuit, an optical communication system and a method of controlling amplification |
| WO2002045300A1 (en) * | 2000-12-01 | 2002-06-06 | Transmode Systems Ab | A transmitter-receiver device and a communication system |
| US6943630B2 (en) | 2000-12-01 | 2005-09-13 | Transmode Systems Ab | Amplifier circuit, an optical communication system and a method of controlling amplification |
| US7212740B2 (en) | 2000-12-01 | 2007-05-01 | Transmode Systems Ab | Transmitter-receiver device and a communication system |
| KR20040050948A (en) * | 2002-12-11 | 2004-06-18 | 한국전자통신연구원 | High speed optoelectronics modules compensated with induction |
| WO2008099507A1 (en) * | 2007-02-16 | 2008-08-21 | Fujitsu Limited | Light receiver |
| JPWO2008099507A1 (en) * | 2007-02-16 | 2010-05-27 | 富士通オプティカルコンポーネンツ株式会社 | Optical receiver |
| JP4998478B2 (en) * | 2007-02-16 | 2012-08-15 | 富士通オプティカルコンポーネンツ株式会社 | Optical receiver |
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