OPTICAL RECEPTION CIRCUIT

摘要

PURPOSE:To obtain a noise characteristic suitable for a transmission code by adding an inductance resonanates in parallel with a junction capacitance of a photodetector and the input capacitor of an amplifier element to a connection section between the photodetector and the amplifier element of a front end section. CONSTITUTION:The inductance 12 is provided to the connection between the photodetector 11 and the amplifier element 13 of the front end section 1. The inductance 12 gives parallel resonance with the junction capacitor of the photodetector 11 and the input capacitor of the amplifier element 13 and the input impedance of the front end part is maximized at the resonance frequency. Thus, the S/N is maximized by adjusting the inductance 12 so as to make the resonance frequency coincident with the signal frequency. Further, an LPF 52 compensates the low frequency characteristic in an equivalent circuit 5 compensating the band characteristic.