JPH10107738A - Optical receiver - Google Patents
Optical receiverInfo
- Publication number
- JPH10107738A JPH10107738A JP8256661A JP25666196A JPH10107738A JP H10107738 A JPH10107738 A JP H10107738A JP 8256661 A JP8256661 A JP 8256661A JP 25666196 A JP25666196 A JP 25666196A JP H10107738 A JPH10107738 A JP H10107738A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- amplifier circuit
- light receiving
- level
- 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.)
- Pending
Links
Landscapes
- Optical Communication System (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明はCATVシステムや
その他の光通信システムで使用される光受信機に関する
ものである。The present invention relates to an optical receiver used in a CATV system and other optical communication systems.
【0002】[0002]
【従来の技術】光受信機は一般に図3に示すような回路
構成であり、受光素子A、縦属接続された2以上の増幅
回路B、利得調整回路Cから構成される。初段の増幅回
路Bは2段目以降の増幅回路Bのプリアンプ的な役割を
なすものである。この光受信機では、入力された光信号
が受光素子Aで電気信号に変換され、この電気信号Aが
初段の増幅回路Bで増幅された後、利得調整回路Cで信
号レベルの大小に応じて減衰されて、レベルが安定化さ
れる。具体的には、電気信号のレベルが大きいときには
減衰量が多く、レベルが小さいときには減衰量が少なく
なる。この安定化された電気信号は2段目以降の増幅回
路Bで所定レベルに増幅され、外部出力となる。2. Description of the Related Art An optical receiver generally has a circuit configuration as shown in FIG. 3, and includes a light receiving element A, two or more amplifier circuits B connected in cascade, and a gain adjustment circuit C. The first-stage amplifier circuit B plays the role of a preamplifier for the second and subsequent amplifier circuits B. In this optical receiver, an input optical signal is converted into an electric signal by a light receiving element A, and the electric signal A is amplified by a first-stage amplifier circuit B, and then is amplified by a gain adjustment circuit C in accordance with the level of the signal. The level is stabilized by being attenuated. Specifically, when the level of the electric signal is large, the attenuation is large, and when the level is small, the attenuation is small. This stabilized electric signal is amplified to a predetermined level by the amplifier circuits B of the second and subsequent stages and becomes an external output.
【0003】[0003]
【発明が解決しようとする課題】図3の光受信機の初段
の増幅回路Bはその利得が固定であり、所定のレンジ内
のレベルの電気信号に対して有効に機能する。即ち、規
定されたレンジ内で、小レベルの信号に対しては後段の
利得調整回路Cや増幅回路Bに対して最低限必要とされ
るレベルを作りだし、大レベルの信号に対しては歪特性
の劣化が許容範囲内に収まる程度に増幅する。しかしな
がら、所定のレンジを下回る小レベルの信号や同レンジ
を上回る大レベルの信号に対しては増幅率の不足や歪特
性の悪化等により有効に機能しなくなる。即ち、光信号
の入力レベルに対するレンジが狭いという問題を持って
いる。また、規定レンジ内の大レベルの信号について、
大きな歪こそ発生しないものの、本来ならば後段増幅回
路Dだけによる増幅で事足りる信号についても初段の増
幅回路Aで増幅が行われるため無駄な電力が消費される
ことになり、省電力化という点で問題を有する。The gain of the first-stage amplifier circuit B of the optical receiver shown in FIG. 3 is fixed, and functions effectively for an electric signal having a level within a predetermined range. That is, within the specified range, the minimum level required for the gain adjustment circuit C and the amplification circuit B at the subsequent stage is created for a low-level signal, and the distortion characteristic is obtained for a high-level signal. Is amplified to such an extent that the deterioration of the element falls within an allowable range. However, a signal of a low level below a predetermined range or a signal of a high level above the same range does not function effectively due to insufficient amplification factor, deterioration of distortion characteristics, and the like. That is, there is a problem that the range for the input level of the optical signal is narrow. For large-level signals within the specified range,
Although a large distortion does not occur, a signal that would otherwise be sufficient only by the latter-stage amplifier circuit D is amplified by the first-stage amplifier circuit A, so that wasteful power is consumed. Have a problem.
【0004】本発明の目的は、広いダイナミックレンジ
を有し、省電力化も可能な光受信機を提供することにあ
る。An object of the present invention is to provide an optical receiver having a wide dynamic range and capable of saving power.
【0005】[0005]
【課題を解決するための手段】本発明のうち請求項1記
載の光受信機は図1に示すように、光信号を受光して電
気信号に変換する受光素子1と、受光素子1が受光する
光信号をモニタ可能なモニタ回路2と、受光素子1から
出力される電気信号を増幅する増幅回路3が2段以上
と、電気信号の信号レベルを安定化する利得調整回路4
を備えた光受信機において、前記モニタ回路2の出力電
圧を利用して初段の増幅回路3の利得を可変制御可能と
したものである。As shown in FIG. 1, the optical receiver according to the first aspect of the present invention includes a light receiving element 1 for receiving an optical signal and converting it into an electric signal. A monitor circuit 2 capable of monitoring an optical signal to be transmitted, an amplifier circuit 3 for amplifying an electric signal output from the light receiving element 1, two or more stages, and a gain adjusting circuit 4 for stabilizing the signal level of the electric signal.
In the optical receiver provided with the above, the gain of the first-stage amplifier circuit 3 can be variably controlled using the output voltage of the monitor circuit 2.
【0006】本発明のうち請求項2記載の光受信機は図
2に示すように、初段増幅回路3にスルー回路5と、利
得調整用増幅回路6と、両回路5、6を切替える切替器
7を設け、受光素子1に入射される光信号レベルが所定
値以上の時には同初段増幅回路3に入力される信号をス
ルー回路5に通し、所定値以下のときは利得調整用増幅
回路6に通すようにしたものである。In the optical receiver according to the second aspect of the present invention, as shown in FIG. 2, a through circuit 5, a gain adjustment amplifier circuit 6, and a switch for switching between the two circuits 5, 6 are provided in the first stage amplifier circuit 3. 7, the signal input to the first-stage amplifier circuit 3 is passed through the through circuit 5 when the optical signal level incident on the light receiving element 1 is equal to or higher than a predetermined value, and is passed to the gain adjustment amplifier circuit 6 when the optical signal level is equal to or lower than the predetermined value. It is made to pass.
【0007】[0007]
【発明の実施の形態1】本発明の光受信機の実施の形態
を図1に基づいて説明する。この光受信機は、光信号を
受光して電気信号に変換する受光素子1と、受光素子1
が受光する光信号(光信号のレベル)をモニタするモニ
タ回路2と、受光素子1から出力される電気信号を増幅
する2段以上の増幅回路3と、初段と2段目の増幅回路
3の間に設けられて電気信号のレベルの安定化を図る利
得調整回路4とを備える。Embodiment 1 An embodiment of an optical receiver according to the present invention will be described with reference to FIG. The optical receiver includes a light receiving element 1 for receiving an optical signal and converting the light signal into an electric signal;
A monitor circuit 2 for monitoring an optical signal (the level of the optical signal) received by the amplifier, an amplifier circuit 3 of two or more stages for amplifying an electric signal output from the light receiving element 1, and an amplifier circuit 3 for the first and second stages. And a gain adjustment circuit 4 provided between them for stabilizing the level of the electric signal.
【0008】前記受光素子1、モニタ回路2、2段目以
降の増幅回路3、利得調整回路4はいずれも従来よりあ
る光受信機で使用されているものと同様のものを使用す
ることができ、例えば図3で示したものと同じものを使
用することができる。図3にはモニタ回路が示されてい
ないが、標準で備わっている。前記モニタ回路2は受光
素子1における受光レベルに応じた電圧を出力するもの
であり、受光レベルが低いと低い電圧を出力し、受光レ
ベルが高いと高い電圧を出力する。The light receiving element 1, the monitor circuit 2, the second and subsequent stages of the amplifier circuit 3, and the gain adjustment circuit 4 can all be the same as those used in conventional optical receivers. For example, the same one as shown in FIG. 3 can be used. Although a monitor circuit is not shown in FIG. 3, it is provided as standard. The monitor circuit 2 outputs a voltage corresponding to the light receiving level of the light receiving element 1, and outputs a low voltage when the light receiving level is low, and outputs a high voltage when the light receiving level is high.
【0009】前記初段増幅回路3はこれまでの固定利得
型のものに変わって可変利得型のものを用いてあり、外
部の制御電圧により増幅利得が可変可能となっている。
この場合、初段の増幅回路3の制御電圧としてモニタ回
路2が出力する出力電圧を入力するようにしてあり、受
光素子1における光信号の受光レベルに連動して利得が
変化するようにしてある。具体的には、受光レベルが高
くなるにつれて利得が引き下げられ、受光レベルが低く
なるにつれて利得が高められるようにしてある。The first-stage amplifier circuit 3 is of a variable gain type instead of the fixed gain type, and the amplification gain can be varied by an external control voltage.
In this case, the output voltage output from the monitor circuit 2 is input as the control voltage of the first-stage amplifier circuit 3, and the gain changes in accordance with the light receiving level of the optical signal in the light receiving element 1. Specifically, the gain is reduced as the light receiving level increases, and the gain is increased as the light receiving level decreases.
【0010】以上説明した光受信機では、光信号の受光
レベルに応じて初段の増幅回路3の利得が適宜調整され
るため、利得不足による雑音の発生や過剰利得による歪
の発生が広範囲にわたって抑制され、許容受光レベルの
拡大が図られる。また、受光レベルが高いときは初段増
幅回路3の利得が低く調整されるため、同増幅回路3に
よる消費電力も抑えられ、全体的に無駄な電力消費が抑
制される。In the optical receiver described above, since the gain of the first-stage amplifier circuit 3 is appropriately adjusted according to the light receiving level of the optical signal, generation of noise due to insufficient gain and generation of distortion due to excessive gain are suppressed over a wide range. Thus, the allowable light receiving level is expanded. Further, when the light receiving level is high, the gain of the first-stage amplifier circuit 3 is adjusted to be low, so that the power consumption of the first-stage amplifier circuit 3 is suppressed, and wasteful power consumption is suppressed as a whole.
【0011】[0011]
【発明の実施の形態2】図2は本発明の光受信機の他の
実施形態を示したものである。この例では実施形態1に
おける初段の増幅回路3を、第1の増幅回路8とそれに
続く第2の増幅回路(利得調整用増幅回路)6及びスル
ー回路5で構成し、第2の増幅回路6とスルー回路5は
その両端の切替器7によりそのどちらか一方を選択する
構成にしてある。切替器7の切り替えは受光素子1のモ
ニタ回路2に設けた比較回路9で行うようにしてある。Embodiment 2 FIG. 2 shows another embodiment of the optical receiver according to the present invention. In this example, the first-stage amplifier circuit 3 in the first embodiment is composed of a first amplifier circuit 8, a subsequent second amplifier circuit (amplifier circuit for gain adjustment) 6, and a through circuit 5, and the second amplifier circuit 6 And the through circuit 5 are configured such that either one of them is selected by the switchers 7 at both ends thereof. The switching of the switch 7 is performed by a comparison circuit 9 provided in the monitor circuit 2 of the light receiving element 1.
【0012】前記比較回路9はモニタ回路2を通じて受
光素子1に受光される光信号のレベルをモニタするよう
にしてあり、比較回路9内に設定した所定の基準値を元
に光信号の受光レベルが適正値より大きいか小さいかを
判断することができるようにしてある。この比較回路9
は受光レベルが所定値を上回っていると判断した場合、
切替器7の接点をスルー回路5側に切り替えて第1の増
幅回路8につづく回路としてスルー回路5を設定し、受
光レベルが所定値を下回っていると判断した場合、切替
器7の接点を第2の増幅回路6側に切り替えて第1の増
幅回路8に続く回路として第2の増幅回路6を設定す
る。The comparison circuit 9 monitors the level of the light signal received by the light receiving element 1 through the monitor circuit 2. The light reception level of the light signal is determined based on a predetermined reference value set in the comparison circuit 9. Is larger or smaller than the appropriate value. This comparison circuit 9
If it is determined that the light reception level exceeds the predetermined value,
The contact of the switch 7 is switched to the through circuit 5 side, and the through circuit 5 is set as a circuit following the first amplifier circuit 8. If it is determined that the light receiving level is lower than a predetermined value, the contact of the switch 7 is changed. Switching to the second amplifier circuit 6 side, the second amplifier circuit 6 is set as a circuit following the first amplifier circuit 8.
【0013】前記初段の増幅回路3において第1の増幅
回路8は常時作動するようになっており、常時駆動電流
が供給されるようになっているが、第2の増幅回路6は
切替器7により選択されたときにだけ駆動電流が供給さ
れ、不要な駆動電流が消費されないようになっている。In the first-stage amplifier circuit 3, the first amplifier circuit 8 is always operated, and a drive current is always supplied. However, the second amplifier circuit 6 is provided with a switch 7 Thus, the drive current is supplied only when selected, and unnecessary drive current is not consumed.
【0014】第1、第2の増幅回路8、6はいずれも利
得が固定されており、小信号に対しては第1、第2の増
幅回路8、6が共に動作してこれら合わせて所望の利得
が達成されるようになっている。言い替えると第1、第
2の増幅回路8、6の一つ一つは利得が小さくしてあ
り、大信号入力時に利得の小さい第1の増幅回路8だけ
が動作して歪特性が悪化しないようにしてある。The gain of each of the first and second amplifier circuits 8 and 6 is fixed, and the first and second amplifier circuits 8 and 6 operate together for a small signal, so that the desired Gain is achieved. In other words, each of the first and second amplifying circuits 8 and 6 has a small gain, so that when a large signal is input, only the first amplifying circuit 8 having a small gain operates to prevent the distortion characteristic from deteriorating. It is.
【0015】以上説明した光受信機では、初段の増幅回
路3における利得が2段階調整であり、実施形態1の連
続変化するものに比べて細かな調整ができないが、ある
レベル以上の信号に対してはスルー回路5が選択される
ので増幅回路3による歪特性の悪化が防止され、また効
率的な省電力を図ることができる。In the optical receiver described above, the gain of the first-stage amplifier circuit 3 is adjusted in two steps, and cannot be adjusted more finely than the continuously changing signal of the first embodiment. In addition, since the through circuit 5 is selected, deterioration of the distortion characteristics due to the amplifier circuit 3 is prevented, and efficient power saving can be achieved.
【0016】[0016]
【発明の効果】本発明の光受信機によれば次のような効
果がある。1.小レベルの信号、大レベルの信号に対応
できるワイドなダイナミックレンジを備えながら大レベ
ルの信号に対して歪特性が改善される。2.初段増幅回
路における無駄な電力消費が解消され、小電力化とな
る。3.後段増幅回路側での利得調整分が少なくて済
み、周波数特性の劣化が小さく、回路構成が容易にな
る。According to the optical receiver of the present invention, the following effects can be obtained. 1. Distortion characteristics are improved with respect to large-level signals while having a wide dynamic range that can handle small-level signals and large-level signals. 2. Useless power consumption in the first-stage amplifier circuit is eliminated, and power consumption is reduced. 3. The amount of gain adjustment on the side of the subsequent-stage amplifier circuit can be reduced, the deterioration of frequency characteristics is small, and the circuit configuration is simplified.
【図1】本発明の光受信機の第1の実施の形態を示した
ブロック図。FIG. 1 is a block diagram showing an optical receiver according to a first embodiment of the present invention.
【図2】本発明の光受信機の第2の実施の形態を示した
ブロック図。FIG. 2 is a block diagram showing a second embodiment of the optical receiver according to the present invention.
【図3】従来の光受信機の一例を示したブロック図。FIG. 3 is a block diagram showing an example of a conventional optical receiver.
1 受光素子 2 モニタ回路 3 増幅回路 4 利得調整回路 5 スルー回路 6 利得調整用増幅回路 7 切替器 REFERENCE SIGNS LIST 1 light receiving element 2 monitor circuit 3 amplifier circuit 4 gain adjustment circuit 5 through circuit 6 gain adjustment amplifier circuit 7 switch
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 FI H04B 10/08 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI H04B 10/08
Claims (2)
素子(1)と、受光素子(1)が受光する光信号をモニ
タ可能なモニタ回路(2)と、受光素子(1)から出力
される電気信号を増幅する増幅回路(3)が2段以上
と、電気信号の信号レベルを安定化する利得調整回路
(4)を備えた光受信機において、前記モニタ回路
(2)の出力電圧を利用して初段の増幅回路(3)の利
得を可変制御可能としたことを特徴とする光受信機。A light receiving element (1) for receiving an optical signal and converting it into an electric signal, a monitor circuit (2) capable of monitoring an optical signal received by the light receiving element (1), and a light receiving element (1). In an optical receiver including two or more stages of an amplifier circuit (3) for amplifying an output electric signal and a gain adjustment circuit (4) for stabilizing the signal level of the electric signal, the output of the monitor circuit (2) is provided. An optical receiver characterized in that the gain of a first-stage amplifier circuit (3) can be variably controlled by using a voltage.
(5)と、利得調整用増幅回路(6)と、両回路
(5)、(6)を切替える切替器(7)を設け、受光素
子(1)に入射される光信号レベルが所定値以上の時に
は同初段増幅回路(3)に入力される信号をスルー回路
(5)に通し、所定値以下のときは利得調整用増幅回路
(6)に通すようにしたことを特徴とする請求項1記載
の光受信機。2. The first stage amplifier circuit (3) is provided with a through circuit (5), a gain adjustment amplifier circuit (6), and a switch (7) for switching between the two circuits (5) and (6). When the level of the optical signal incident on the element (1) is equal to or higher than a predetermined value, the signal input to the first-stage amplifier circuit (3) is passed through the through circuit (5). The optical receiver according to claim 1, wherein the optical receiver is configured to pass through (6).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8256661A JPH10107738A (en) | 1996-09-27 | 1996-09-27 | Optical receiver |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8256661A JPH10107738A (en) | 1996-09-27 | 1996-09-27 | Optical receiver |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH10107738A true JPH10107738A (en) | 1998-04-24 |
Family
ID=17295721
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8256661A Pending JPH10107738A (en) | 1996-09-27 | 1996-09-27 | Optical receiver |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH10107738A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003018095A (en) * | 2001-07-04 | 2003-01-17 | Synclayer Inc | Optical receiver |
JP2006262353A (en) * | 2005-03-18 | 2006-09-28 | Yagi Antenna Co Ltd | Optical receiver |
US7605358B2 (en) | 2004-07-22 | 2009-10-20 | Hamamatsu Photonics K.K. | Photodetector having dual photodiode and gain adjusting amplifiers |
JP2012134962A (en) * | 2010-12-17 | 2012-07-12 | Internatl Business Mach Corp <Ibm> | Adaptive power efficient receiver architecture |
JP2013026636A (en) * | 2011-07-14 | 2013-02-04 | Hochiki Corp | Optical receiver |
-
1996
- 1996-09-27 JP JP8256661A patent/JPH10107738A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003018095A (en) * | 2001-07-04 | 2003-01-17 | Synclayer Inc | Optical receiver |
US7605358B2 (en) | 2004-07-22 | 2009-10-20 | Hamamatsu Photonics K.K. | Photodetector having dual photodiode and gain adjusting amplifiers |
JP2006262353A (en) * | 2005-03-18 | 2006-09-28 | Yagi Antenna Co Ltd | Optical receiver |
JP4620509B2 (en) * | 2005-03-18 | 2011-01-26 | 八木アンテナ株式会社 | Optical receiver |
JP2012134962A (en) * | 2010-12-17 | 2012-07-12 | Internatl Business Mach Corp <Ibm> | Adaptive power efficient receiver architecture |
JP2013026636A (en) * | 2011-07-14 | 2013-02-04 | Hochiki Corp | Optical receiver |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5530923A (en) | Dual mode transmission system with switched linear amplifier | |
US6097252A (en) | Method and apparatus for high efficiency power amplification | |
JP2996170B2 (en) | Gain control circuit | |
CA2189718A1 (en) | Power amplifier system with variable output | |
JP2002033629A (en) | Gain variable amplifier circuit, and terminal provided with the same | |
AU1508799A (en) | Power saving device for radio communication terminal | |
JPH06350496A (en) | Automatic gain controller | |
US20040014450A1 (en) | Signal receiving apparatus and gain control method using analog control AGC and step control AGC | |
US6201440B1 (en) | Power amplifier and control circuit thereof | |
JPH09107299A (en) | Receiving amplifier | |
JPH10107738A (en) | Optical receiver | |
GB2350957A (en) | A multi-stage reflection amplifier with means for preventing backwards propagation | |
EP0944166A1 (en) | Automatic dynamic range controlling circuit | |
US6445729B1 (en) | Radio signal transceiver apparatus | |
JPH09116360A (en) | Automatic gain control amplifier | |
CA2070027C (en) | Portable telephone | |
JP2699698B2 (en) | Receiver | |
CS130292A3 (en) | Signal lever control circuit | |
JP2002076949A (en) | Transmission power controlling apparatus and method therefor | |
JPH1051323A (en) | Transmitter | |
KR20040095286A (en) | Front stage amplifier with different modes | |
EP1584169A1 (en) | Agc circuit arrangement for a tuner | |
KR0150370B1 (en) | Single body type if transmitting amplifier | |
JPH0993192A (en) | Optical reception circuit | |
JP2001086176A (en) | Digital transmitter-receiver |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041124 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20041207 |
|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20050406 |