| 摘要 |
PURPOSE:To realize an photodetection equalizing filter of Gauss approximation suitable for circuit integration corresponding to a high frequency and to avoid a problem of constant selection or design attended with a high frequency coil by constituting each low pass filter by a resistor and a capacitor without using the high frequency coil. CONSTITUTION:In the photodetection equalizing filter used for a large capacity optical transmission photodetector, plural low pass filters comprising capacitors C1-C3 and resistors R1-R3 are connected in cascade via a buffer element. The number of stages of CR filters, the values of the capacitors, C1-C3 and resistors R1-R3 are selected so that the circuit characteristic is to be of Gauss type photodetection equalizing filter characteristic. The degree of approximation to the Gauss type photodetection equalizing filter characteristic depends on number of stages of the CR filters and in figure, 3 stages are shown. Thus, the capacitors and the resistors cope with high frequency application and circuit integration, then the photodetection equalizing filter suitable for many high frequencies and circuit integration is obtained. |
