| 摘要 |
PROBLEM TO BE SOLVED: To constitute an analog phase comparator, without the use of a differential circuit and a full rectifier circuit, even in an optical transmission system which uses non-return to zero(NRZ) data signals. SOLUTION: A data input terminal and a clock input terminal are connected to a phase comparator circuit PD1, a data input terminal is connected to a phase comparator circuit PD2 and connected from the clock input terminal via a 90 deg. phase shifter to the clock input terminal of the phase comparator circuit PD2: and Furthermore, the output terminals of the phase comparator circuits PD1 and PD2 are connected to the input of an exclusive OR circuit. Due to a data signal converting circuit having such a style, the NRZ signal to be used for the optical transmission system can be converted into a return-to zero(RZ) signal which can be compared with a clock signal. |
