Optical AGC control circuit and attenuation value acquisition method thereof

Abstract

The present invention discloses an optical AGC control circuit and an attenuation value acquisition method thereof, relating to the optical communication field, with an aim to make a radio frequency electric signal level output by an optical reception device keep constant through an automatic change of the radiofrequency signal attenuation value when the optical reception power changes in certain extent. The present invention adopt such a technology approach comprising the following steps: an optical receiver outputs a detection voltage which is in proportion to the optical reception power to a sampling unit; an attenuation value calculating unit initially calculates the optical reception power according to the detection voltage, and then calculates the radio frequency electric signal attenuation value according to a formula 2X(10 + 10 X1g (optical reception power)); and a gain adjusting unit adjusts the level of the output radio frequency electric signal according to the attenuation value so as to realize the optical AGC function. The optical AGC control circuit and the attenuation value acquisition method thereof provided by the present invention are mainly used for optical reception devices in an optical communication network.

Description

technical field [0001] The invention relates to the field of optical communication systems, in particular to a circuit for realizing automatic radio frequency gain control by optical receiving power and a method for acquiring radio frequency attenuation values. Background technique [0002] At present, in the radio frequency broadband optical communication system, the front-end optical transmitting equipment ages with time, and the transmitting power will gradually decrease, and the optical receiving power of the corresponding optical receiving equipment will also decrease. In systems without optical AGC function, the optical receiving power The output level of the device will also decrease accordingly, affecting the reliability of signal transmission. [0003] In addition, in the same system network, the distance between each optical receiving device and the front-end optical transmitting device is different, the fiber link loss value is also different, and the received opt...

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Problems solved by technology

However, such attenuation value processing method has the following disadvantages: 1. It cannot provide the continuous correspondence between the electrical signal output by the photoelectric transducer unit and the attenuation value, which greatly affects the control accuracy; 2. The control range of the optical AGC control circuit is limited by the table. restrict

It is not difficult to conclude that the existing optical AGC control circuit cannot solve the above-mentioned tedious problem of system debugging.

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