| 摘要 |
In an optical fibre receiver, the modulated light falls on a p-i-n diode (PD) connected to the input of an operational amplifier (A). This amplifier is shunted by a load resistor (R), which in turn is shunted by a non-linear Schottky diode (SD). This provides the receiver with a low pass response having a relatively long time constant. In addition to this, the a.c. coupling response for the connection to the next stage of the system has a relatively short time constant. These two time constants combine to give an overall characteristic with a relatively narrow bandwidth. This prevents a large pulse from spoiling the sensitivity of the receiver to a following smaller pulse. <IMAGE>
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