The Realization Of Optical Receiver In The Wideband HFC

Because the wideband HFC has a better capability of transmission and anti-jamming, it is fit to deliver bidirectional digital signals, at present, it has been the international developmental mainstream of CATV. Being the important transmission equipment in wideband HFC, the performance index of optical receivers is the general embodiment of wideband HFC, the stand or fall of performance index of optical receivers directly decide the signal quality of user end. With the popularization of HFC and the rebuild of the primary optical network, the prevenient optical receivers have not filled the developmental requirements because they have the disadvantages of less fan-out, bad abilities of driving loadings and being unfit to deliver digital signals. So it is very important to design a optical receiver with good performance.This paper introduces the performance index of optical receivers,moreover, based on the national standards it emphasizes the design of the optical receiving module, power amplifier and the assistant circuit.Being the pivotal part of the optical receiver, the optical receiving module is made of the optical detector, the preamplifier and the suited circuit. This paper chooses the InGaAs PIN photoelectricity diode. By the principle of the preamplifier of commutative resistance, this paper designs a applied and innovative circuit of preamplifier. The preamplifier is matched with the optical detector by the wideband transformer. This paper achieves the aim. Incorporate modules are used in the power amplifier, according as the flow of signal magnifying, low yawp and push-pull modules are used in the front circuit, power doublers are used in the back circuit, matching circuit is designs in the paper. The plus and equilibria circuit are used in the power amplifier, such as adjusting attenuators and adjusting equalizers. The performance index of the optical receiver is improved effectively. This paper also designs the assistant circuit including the optical power showing circuit, echoplex module and source.Finally a sample optical receiver is produced according to the design, moreover, it is tested in the laboratory and the residential area, the performance index accords with the national standards and excels traditional optical receivers, this paper has good applied meaning and referenced value.