CN202364220U - Automatic gain control (AGC) optical receiver module - Google Patents

Abstract

The utility model discloses an automatic gain control (AGC) optical receiver module, which comprises a photo-electricity converting unit, a gain adjustment unit and a sample processing unit. The AGC optical receiver module is characterized by further comprising a radio-frequency signal amplifying unit and a microcomputer processing unit. The signal output end of the photo-electricity converting unit is respectively and electrically connected to the input end of the radio-frequency signal amplifying unit and the input end of the sample processing unit. The output end of the radio-frequency signal amplifying unit is electrically connected to the gain adjustment unit. the output end of the sample processing unit is electrically connected to the input end of the microcomputer processing unit. The output end of the microcomputer processing unit is electrically connected to the control end of the gain adjustment unit, and the radio-frequency signal amplifying unit is a secondary amplifying circuit. The AGC optical receiver module has the advantages that the electrical level of an attenuated electrical signal is maintained to be stable, the adjusting range of the gain adjustment unit is 0-20 dB, the control range of a corresponding optical signal is improved to be a range from -8 to +20 dBm, all the users requirements are met, the control accuracy is high, and the electrical signal output finally is stable.

Description

The AGC Optical Receivers

[technical field]

The utility model relates to optical receiving circuit, particularly a kind of AGC Optical Receivers.

[background technology]

Along with the fast development of electronic technology and optical fiber communication technology, optical-fibre communications is low because of the loss that it has, transmission frequency bandwidth, capacity is big, volume is little, electromagnetic interference in light weight, anti-, be difficult for advantages such as cross-talk, enjoys the insider to favor, and develops very fast.At present, optical fiber cable has got into the every field of wire communication, comprises fields such as post and telecommunications, broadcast communication, power communication, oil communication and military communication.Generally speaking, in order to reach farther Distance Transmission, often increase the Optical Receivers that can receive the faint light power signal at the terminal of Optical Fiber Transmission; Because optical power signals has loss in various degree in the process of transmission, so in the optical power signals of terminal node certain excursion is arranged, the jitter after amplifying; Therefore, need a control circuit to come the steady of regulating and controlling output voltage, the control range of AGC control circuit of the prior art is little; Be generally-6～0dBm; Because these two kinds of schemes all design on the mainboard, the dynamic range of index is restricted, for greater than-6～0dBm scope; Its control action is very not obvious, can not satisfy all users' the scope of application.

[summary of the invention]

The purpose of the utility model is to overcome above-mentioned deficiency, provides a kind of its control range big, the AGC Optical Receivers that control precision is high.

The purpose of the utility model is to realize like this: it comprises photoelectricity conversion unit (1), gain adjusting unit (3), sample processing unit (4); Its improvement is: also comprise radiofrequency signal amplifying unit (2) and computer processing unit (5); The signal output part of said photoelectric conversion unit (1) is electrically connected at the input of radiofrequency signal amplifying unit (2) and the input of sample processing unit (4) respectively; Convert light signal to the signal of telecommunication and export radiofrequency signal amplifying unit (2) to; Simultaneously, sample processing unit (4) is taked the signal of telecommunication of said photoelectric conversion unit (1) output; The output telecommunications of said radiofrequency signal amplifying unit (2) is connected in gain adjusting unit (3), exports the signal of telecommunication after amplifying to gain adjusting unit (3); The output of said sample processing unit (4) is electrically connected at the input of computer processing unit (5); The signal of telecommunication to taking carries out judgment processing, and exports computer processing unit (5) to through the A/D conversion, and the output of computer processing unit (5) is electrically connected at the control end of gain adjusting unit (3); The signal of telecommunication to sample processing unit (4) input carries out processing operations; Calculate the corresponding pad value of the signal of telecommunication, and export one and control signal to gain adjusting unit (3), the ride gain adjustment.

Said radiofrequency signal amplifying unit (2) comprises first order amplifying circuit (21), second level amplifying circuit (22) and transformation filter circuit (23); Described gain adjusting unit (3) is electrically connected between first order amplifying circuit (21) and the second level amplifying circuit (22), and transformation filter circuit (23) is electrically connected at the output of second level amplifying circuit (22).

In the said structure; Said sample processing unit comprises singlechip chip (U8), program input port (J2) and power supply circuits; Said power supply circuits are connected with the energization pins of singlechip chip (U8), and program input port (J2) is connected with corresponding pin on the singlechip chip (U8).

The utility model beneficial effect is: the utility model converts light signal to the signal of telecommunication through photoelectric conversion unit, exports this signal of telecommunication to the radiofrequency signal amplifying unit and carries out the signal amplification, and the signal of telecommunication of process processing and amplifying exports gain adjusting unit to; Meanwhile, sample processing unit is taked the signal of telecommunication of photoelectric conversion unit output, and it is carried out the A/D conversion; Export computer processing unit to dc level signal; The corresponding pad value of this level signal is judged, calculated to computer processing unit to the level signal of sampling unit output, simultaneously, converts this pad value to a control signal and export gain adjusting unit to; Gain adjusting unit is carried out the decay of respective amplitude to the signal of telecommunication of radio frequency signal amplification unit circuit output; By this, make the level of the signal of telecommunication after decaying keep stable, the adjusting range of its gain adjusting unit is 0-20dB; The control range of the light signal corresponding with it also brings up to-8 to+2dBm; Satisfy all user's requests, control precision is high, and the signal of telecommunication of final output is more stable; In addition; The radiofrequency signal circuit adopts secondary to amplify, and the input signal of gain adjusting unit and the adjusted signal that gains is all amplified, finally through impedance matching and filtering output; Make the adjusting range of gain unit of adjustment increase, the signal of telecommunication of output is also more stable.

Description of drawings

Fig. 1 is the theory diagram of the utility model

Fig. 2 is the schematic diagram of the utility model

[embodiment]

Below in conjunction with accompanying drawing and concrete execution mode the utility model is described further:

With reference to shown in Figure 1, the utility model has disclosed a kind of AGC Optical Receivers, and it comprises photoelectricity conversion unit 1, gain adjusting unit 3, sample processing unit 4, also comprises radiofrequency signal amplifying unit 2 and computer processing unit 5; Wherein, The signal output part of photoelectric conversion unit 1 is electrically connected at the input of radiofrequency signal amplifying unit 2 and the input of sample processing unit 4 respectively; Convert light signal to the signal of telecommunication and export radiofrequency signal amplifying unit 2 to; Simultaneously, sample processing unit 4 is taked the signal of telecommunication of said photoelectric conversion unit 1 output; The output telecommunications of radiofrequency signal amplifying unit 2 is connected in gain adjusting unit 3, exports the signal of telecommunication after amplifying to gain adjusting unit 3; The output of sample processing unit 4 is electrically connected at the input of computer processing unit 5; The signal of telecommunication to taking carries out judgment processing, and changes the unit 5 that exports MICROCOMPUTER PROCESSING to through A/D, and the output of computer processing unit 5 is electrically connected at the control end of gain adjusting unit 3; The signal of telecommunication to sample processing unit 4 inputs carries out processing operations; Calculate the corresponding pad value of the signal of telecommunication, and export one and control signal to gain adjusting unit 3, the ride gain adjustment.Radiofrequency signal amplifying unit 2 comprises first order amplifying circuit 21, second level amplifying circuit 22 and transformation filter circuit 23; Described gain adjusting unit 3 is electrically connected between first order amplifying circuit 21 and the second level amplifying circuit 22, and transformation filter circuit 23 is electrically connected at the output of second level amplifying circuit 22.

With reference to shown in Figure 2, the pin of each unit is corresponding to be connected, and light signal gets into the photocoupler (PIN pipe) in the photoelectric conversion unit 1, converts light signal to the signal of telecommunication, carries out the 3 pin output of RF impedance coupling back from transformer T1 through transformer T1; C1, R1, R2 form the sample conversion circuit, and C1 is a filter capacitor, and C2, C3, C4, R3 form filter circuit, and L1 and C6 play impedance fine setting effect to signal.Forming of sample processing unit 4 by singlechip chip U8, program input port J2 etc.; Singlechip chip U8 is through the signal sampling of port P0.6 to photoelectric conversion unit 1; Judge through singlechip chip U8 internal processes; Again through inner A/D conversion back output current signal to computer processing unit 5, when the inner A/D conversion of singlechip chip U8 output current produces pressure drop during to ground through resistance R 13, the resistance R 15 power takings resistance R13 force feed that powers on is gone into operational amplifier U7B and is carried out multiple and amplify; Through correlation computations formula in the operational amplifier calculate resistance R 14 and resistance R 16 resistance values; Operational amplifier U7A is to establish water circuit for the back level partly, but the sustaining voltage value is steady, and voltage signal exports the control end of gain adjusting unit 3 to through the output of operational amplifier U7A; Pad value according to computer processing unit 5 is adjusted the signal of telecommunication gain from radiofrequency signal amplifying unit 2, and adjusting range is 0-20dB; Resistance R 6, resistance R 12 are as the bias circuit of Q1, Q2; Resistance R 7, R8, R9 are as the build-out resistor of Q1, Q2; Capacitor C 19, C20 adjust flat permanent effect to the biasing circuit slight resistance; Resistance R 10, R11 are as the flat permanent bleeder circuit of gain adjusting unit 3 voltages, and capacitor C 18, C21 are capacitances.Diode D1 in the radiofrequency signal amplifying unit 2, diode D2 are 5V protection diode; Capacitor C 7, capacitor C 8 and capacitor C 12, capacitor C 13 are capacitance; Resistance R 4 and capacitor C 10 are used for the signal impedance fine setting with resistance R 5 and capacitor C 11; Capacitor C 9 and capacitor C 14 are power filtering capacitors, and the signal of telecommunication that final adjustment is accomplished carries out exporting from 2 pin after the impedance matching through transformer T2 once more, and wherein capacitor C 15, capacitor C 16, inductance L 5 are formed a filter circuit; Can filter 50MHz signal in the past, capacitor C 17 is used for the reflection fine setting.

Owing to adopt the foregoing circuit structure, convert light signal to the signal of telecommunication through photoelectric conversion unit 1, export this signal of telecommunication to radiofrequency signal amplifying unit 2 and carry out signal and amplify; The signal of telecommunication through processing and amplifying exports gain adjusting unit 3 to, and meanwhile, sample processing unit 4 is taked the signal of telecommunication of photoelectric conversion unit 1 output; And it is carried out A/D transform, exporting computer processing unit 5 to dc level signal, the corresponding pad value of this level signal is judged, calculated to the level signal of 5 pairs of sample processing units of computer processing unit, 4 outputs; Simultaneously; Convert this pad value to a control signal and export gain adjusting unit 3 to, the signal of telecommunication of 3 pairs of radio frequency signal amplification unit 2 circuit outputs of gain adjusting unit carries out the decay of respective amplitude, by this; Make the level of the signal of telecommunication after decaying keep stable; The adjusting range of its gain adjusting unit 3 is 0-20dB, and the control range of the light signal corresponding with it also brings up to-8 to+2dBm, satisfies all user's requests; Control precision is high, and the signal of telecommunication of final output is more stable.

According to the announcement and the instruction of above-mentioned specification, those skilled in the art in the invention can also carry out suitable change and modification to above-mentioned execution mode.Therefore, the embodiment that discloses and describe above the present invention is not limited to also should fall in the protection range of claim of the present invention modifications more of the present invention and change.In addition, although used some specific terms in this specification, these terms are explanation for ease just, the present invention is not constituted any restriction.

Claims (2)

1. AGC Optical Receivers; It comprises photoelectricity conversion unit (1), gain adjusting unit (3), sample processing unit (4); It is characterized in that: also comprise radiofrequency signal amplifying unit (2) and computer processing unit (5); The signal output part of said photoelectric conversion unit (1) is electrically connected at the input of radiofrequency signal amplifying unit (2) and the input of sample processing unit (4) respectively; Convert light signal to the signal of telecommunication and export radiofrequency signal amplifying unit (2) to, simultaneously, sample processing unit (4) is taked the signal of telecommunication of said photoelectric conversion unit (1) output; The output telecommunications of said radiofrequency signal amplifying unit (2) is connected in gain adjusting unit (3), exports the signal of telecommunication after amplifying to gain adjusting unit (3); The output of said sample processing unit (4) is electrically connected at the input of computer processing unit (5); The signal of telecommunication to taking carries out judgment processing, and exports computer processing unit (5) to through the A/D conversion, and the output of computer processing unit (5) is electrically connected at the control end of gain adjusting unit (3); The signal of telecommunication to sample processing unit (4) input carries out processing operations; Calculate the corresponding pad value of the signal of telecommunication, and export one and control signal to gain adjusting unit (3), the ride gain adjustment;

Said radiofrequency signal amplifying unit (2) comprises first order amplifying circuit (21), second level amplifying circuit (22) and transformation filter circuit (23); Described gain adjusting unit (3) is electrically connected between first order amplifying circuit (21) and the second level amplifying circuit (22), and transformation filter circuit (23) is electrically connected at the output of second level amplifying circuit (22).

2. AGC Optical Receivers according to claim 1; It is characterized in that: said sample processing unit comprises singlechip chip (U8), program input port (J2) and power supply circuits; Said power supply circuits are connected with the energization pins of singlechip chip (U8), and program input port (J2) is connected with corresponding pin on the singlechip chip (U8).

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