JPS6119189B2 - - Google Patents
Info
- Publication number
- JPS6119189B2 JPS6119189B2 JP54079520A JP7952079A JPS6119189B2 JP S6119189 B2 JPS6119189 B2 JP S6119189B2 JP 54079520 A JP54079520 A JP 54079520A JP 7952079 A JP7952079 A JP 7952079A JP S6119189 B2 JPS6119189 B2 JP S6119189B2
- Authority
- JP
- Japan
- Prior art keywords
- filter
- light receiving
- receiving element
- amplifier
- signal
- 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
Links
- 230000003287 optical effect Effects 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/66—Non-coherent receivers, e.g. using direct detection
- H04B10/69—Electrical arrangements in the receiver
- H04B10/697—Arrangements for reducing noise and distortion
- H04B10/6973—Arrangements for reducing noise and distortion using noise matching networks
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Light Receiving Elements (AREA)
- Optical Communication System (AREA)
Description
【発明の詳細な説明】 本発明は光受信回路に関するものである。[Detailed description of the invention] The present invention relates to an optical receiving circuit.
従来の光受信回路は第１図に示すものが一般的
である。 A typical conventional optical receiving circuit is shown in FIG.
すなわち、受光素子１とアースとの間に抵抗２
を接続し、この接続点に増幅器３を付加構成して
いる。 In other words, a resistor 2 is connected between the light receiving element 1 and the ground.
is connected, and an amplifier 3 is additionally configured at this connection point.
この回路の動作は次の通りである。 The operation of this circuit is as follows.
図面には矢印で示すフアイバ等を介して伝達さ
れてきた光信号は受光素子１によつて電気（電
流）信号に変換され、さらに抵抗２の両端ではこ
の電流に比例した電圧に変換される。 An optical signal transmitted through a fiber or the like indicated by an arrow in the drawing is converted into an electric (current) signal by the light receiving element 1, and further converted into a voltage proportional to this current at both ends of the resistor 2.
この信号電圧を増幅器３によつて所要の大きさ
に増幅して取り出している。 This signal voltage is amplified to a required magnitude by an amplifier 3 and extracted.
しかし、この受信回路には次のような欠点があ
る。受光素子には漂遊容量があり、一方増幅器に
は入力容量が存在する。従つて、高い周波数にお
いて取り扱う場合、上記２つの容量のリアクタン
スが無視できなくなり、受光素子の負荷インピー
ダンスが低下し、信号電圧が小さくなる。 However, this receiving circuit has the following drawbacks. The light receiving element has stray capacitance, while the amplifier has input capacitance. Therefore, when handling at a high frequency, the reactance of the two capacitors cannot be ignored, the load impedance of the light receiving element decreases, and the signal voltage decreases.
従つて、増幅器出力における信号も小さくな
り、SN比（信号対雑音比）が悪化する。 Therefore, the signal at the amplifier output also becomes smaller, and the signal-to-noise ratio (SN ratio) deteriorates.
従つて、本発明の目的は上述した従来装置の欠
点を解消し、高い周波数においても大きなSN比
を有する光受信器を提供しようとするにある。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device and to provide an optical receiver having a large signal-to-noise ratio even at high frequencies.
本発明受信器によれば、受光素子および増幅器
入力に存在する静電容量を積極的に利用して帯域
フイルタを形成し、高い周波数においても受光素
子の負荷インピーダンスを低下させず、これによ
り、信号電圧の減衰を防ぎ、大きなSN比を確保
することができる。 According to the receiver of the present invention, a bandpass filter is formed by actively utilizing the capacitance present in the light receiving element and the amplifier input, and the load impedance of the light receiving element is not reduced even at high frequencies, thereby allowing the signal to be transmitted. This prevents voltage attenuation and ensures a high signal-to-noise ratio.
次に、本発明による光受信回路を図示の実施例
につき説明する。 Next, an optical receiving circuit according to the present invention will be described with reference to illustrated embodiments.
第２図に示すように、受光素子１の一方に直流
電圧を加え、他方にフイルタのインピーダンスに
相当する抵抗２を接続する。 As shown in FIG. 2, a DC voltage is applied to one side of the light receiving element 1, and a resistor 2 corresponding to the impedance of the filter is connected to the other side.
また、これらの接続点と増幅器３との間にはイ
ンダクタンス６，７および８、ならびに可変コン
デンサ９，１０および１１を接続して帯域フイル
タを形成する。この際、図示のように受光素子１
の漂遊容量４および増幅器の入力容量５をも含め
て帯域フイルタを形成するのが好適である。 Further, inductances 6, 7 and 8 and variable capacitors 9, 10 and 11 are connected between these connection points and amplifier 3 to form a bandpass filter. At this time, as shown in the figure, the light receiving element 1
Preferably, the stray capacitance 4 and the input capacitance 5 of the amplifier are also included to form a bandpass filter.
フイルタの他方には抵抗２と同じ値のフイルタ
成端用抵抗１２を接続する。 A filter terminating resistor 12 having the same value as the resistor 2 is connected to the other side of the filter.
第３図にはかかる回路の等価回路を示す。 FIG. 3 shows an equivalent circuit of such a circuit.
かようにして形成された帯域フイルタは可変コ
ンデンサ９〜１１を調整することにより適当な帯
域フイルタ特性を得ることができる。 The thus formed bandpass filter can obtain appropriate bandpass filter characteristics by adjusting the variable capacitors 9 to 11.
すなわち、フイルタの形成により受光素子の負
荷インピーダンスを増加させて信号出力を増大さ
せると同時に使用帯域外の不要雑音出力を減衰さ
せることができる。 That is, by forming the filter, it is possible to increase the load impedance of the light receiving element and increase the signal output, and at the same time, it is possible to attenuate the unnecessary noise output outside the band of use.
この結果出力のSN比を大きくとることができ
る。 As a result, the SN ratio of the output can be increased.
また、第４図に示すように受光素子１と増幅器
３との間に入力容量５をフイルタ構成要素とする
ような低域フイルタ２０を形成して挿入すれば、
低周波から使用帯域までの出力信号特性を平担化
することができる。 Furthermore, if a low-pass filter 20 having an input capacitor 5 as a filter component is formed and inserted between the light receiving element 1 and the amplifier 3 as shown in FIG.
Output signal characteristics from low frequencies to the usage band can be leveled.
上述したように、本発明におけるようなフイル
タを挿入することにより多くの利点が得られ、さ
らに同一漂遊容量の受光素子を使用し、同じSN
比を確保する場合、本発明フイルタを付加すれば
使用帯域を大きくすることができる。 As mentioned above, many advantages are obtained by inserting a filter as in the present invention, and in addition, the same stray capacitance photodetector and the same SN
If the ratio is to be ensured, the usable band can be increased by adding the filter of the present invention.
本発明は上述した処に限定されることなく、本
発明の範囲内で種々の変更を加えることができ
る。 The present invention is not limited to the above description, and various changes can be made within the scope of the present invention.
第１図は従来の光受信回路図、第２図は本発明
の光受信回路図、第３図は第２図のフイルタ部分
の等価回路図、第４図は低域フイルタを形成した
例の回路図である。
１：受光素子、２：受光素子の負荷抵抗、３：
増幅器、４：受光素子の漂遊容量、５：増幅器の
入力容量、６，７，８：帯域フイルタ用インダク
タンス、９，１０，１１：フイルタ調整可変コン
デンサ、１２：フイルタ成端抵抗、１３，１４，
１５：フイルタの等価インダクタンス、１６，１
７，１８：フイルタの等価容量、１９：受光素子
の等価定電流源、２０：低域フイルタ。
Fig. 1 is a conventional optical receiving circuit diagram, Fig. 2 is an optical receiving circuit diagram of the present invention, Fig. 3 is an equivalent circuit diagram of the filter portion of Fig. 2, and Fig. 4 is an example of forming a low-pass filter. It is a circuit diagram. 1: Light receiving element, 2: Load resistance of the light receiving element, 3:
Amplifier, 4: Stray capacitance of light receiving element, 5: Input capacitance of amplifier, 6, 7, 8: Inductance for bandpass filter, 9, 10, 11: Filter adjustment variable capacitor, 12: Filter termination resistor, 13, 14,
15: Equivalent inductance of filter, 16,1
7, 18: Equivalent capacitance of filter, 19: Equivalent constant current source of light receiving element, 20: Low-pass filter.
Claims (1)
て、光受信部に、受光素子の漂遊容量と、増幅器
の入力容量およびインダクタンスと可変コンデン
サによる帯域フイルタを形成付加したことを特徴
とする光受信回路。1. An optical transmitter/receiver for transmitting narrowband signals, characterized in that an optical receiver circuit is provided with a bandpass filter formed by the stray capacitance of a light receiving element, the input capacitance and inductance of an amplifier, and a variable capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7952079A JPS562673A (en) | 1979-06-22 | 1979-06-22 | Optical receiver circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7952079A JPS562673A (en) | 1979-06-22 | 1979-06-22 | Optical receiver circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS562673A JPS562673A (en) | 1981-01-12 |
| JPS6119189B2 true JPS6119189B2 (en) | 1986-05-16 |
Family
ID=13692246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7952079A Granted JPS562673A (en) | 1979-06-22 | 1979-06-22 | Optical receiver circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS562673A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2952302B2 (en) * | 1989-03-13 | 1999-09-27 | 日本電信電話株式会社 | Light receiving element |
| EP0520308A2 (en) * | 1991-06-27 | 1992-12-30 | Alcatel SEL Aktiengesellschaft | Amplifying circuit device |
| JP2007134385A (en) * | 2005-11-08 | 2007-05-31 | Yokogawa Electric Corp | Method for manufacturing optical receiver module |
| JP5367858B2 (en) * | 2012-02-24 | 2013-12-11 | 日本オクラロ株式会社 | Optical receiver module and method of manufacturing optical receiver module |
-
1979
- 1979-06-22 JP JP7952079A patent/JPS562673A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS562673A (en) | 1981-01-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4291276A (en) | Equalizer amplifier | |
| US4306200A (en) | Selective amplifier | |
| US4370624A (en) | Low noise amplifier circuit with reduced low-frequency gain | |
| HK24687A (en) | Saw filter network | |
| US4297660A (en) | Electric circuit using surface acoustic wave device | |
| US4326172A (en) | Tunable active high-pass filter | |
| US4303889A (en) | Filter circuit | |
| CA1206536A (en) | High frequency band-pass amplifier with adjustable impedance and oscillator including it | |
| US4331927A (en) | Noninverting amplifier circuit with low input impedance | |
| JPS5923642A (en) | Front end circuit for infrared ray receiver | |
| US4087762A (en) | Cable equalization resonant amplifier circuit | |
| US4287491A (en) | Circuit for selectively obtaining automatic dynamic compression or expansion | |
| SU371661A1 (en) | BSESOYUSKAYA | |
| KR870002811Y1 (en) | Tone control circuit | |
| US3155928A (en) | Bridged-t frequency rejection filter | |
| RU2137291C1 (en) | Active broad-band piezoelectric filter | |
| JPS61227414A (en) | Band variable filter | |
| JPH0224259Y2 (en) | ||
| JPS602662Y2 (en) | Narrowband amplifier circuit | |
| JPS5931052Y2 (en) | band pass filter | |
| SU944076A1 (en) | Bandpass active rc-filter | |
| JPH06284090A (en) | Optical receiver | |
| SU1142886A1 (en) | Rejection filter | |
| SU985936A1 (en) | Synchronous rejection filter | |
| EP1003285B1 (en) | Loudness device |