| 摘要 |
<p>An electronic circuit (50) for receiving and discriminating modulated light of a specific modulation frequency or within a specific modulation frequency range, comprises a photodiode detector (52) responsive to light incident thereto for generating an electric current signal. The electronic circuit further comprises a controllable shunt (54) connected in parallel with the photodiode detector (52) and controllable between a first operational mode in which the electric current is shunted and a second operational mode in which the electric current is not shunted, and a control circuit (56) connected to the photodiode detector (52) and the controllable shunt (54) for controlling the controllable shunt (54) into the first operational mode provided the electric current signal does not include a signal of the specific modulation frequency or within the specific modulation frequency range, or for controlling the controllable shunt (54) into the second operational mode provided the electric current signal includes a signal of the specific modulation frequency or within the specific modulation frequency range.</p> |
