This set of Optical Communications Multiple Choice Questions & Answers (MCQs) focuses on “The Optical Receiver Circuit”.
1. ____________ limits receiver sensitivity.
b) Depletion layer
Explanation: Receiver noise affects receiver sensitivity. It can dictate the overall system design. The noise can be temperature, environmental factor or due to components.
2. A ____________ performs the linear conversion of the received optical signal into an electric current.
Explanation: An optical signal is always fed to a detector. A detector is an opto – electronic converter which linearly converts the received optical signal into an electric current.
3. __________ are provided to reduce distortion and to provide a suitable signal shape for the filter.
Explanation: Optical detectors are linear devices. They do not introduce distortion themselves but other components may exhibit nonlinear behaviour. To compensate for distortion, an equalizer is provided in the receiver circuit.
4. A _________ maximizes the received signal-to-noise ratio in the receiver circuitry.
Explanation: A filter reduces the noise bandwidth as well as inbounds noise levels. A filter maximizes the received signal-to-noise ratio while preserving the essential features of the signal. It also reduces ISI.
5. ________ can be operated in three connections.
Explanation: FET’s or bipolar transistors are operated in three useful connections. These are the common emitter, the common base or gate, and the emitter or source follower.
6. How many structures of pre-amplifiers exist?
Explanation: The basic structures of pre-amplifiers are observed in three forms. These are low-impedance, high-impedance and trans-impedance front end preamplifier structures.
7. What is the main factor contributing to the choice of the operational amplifier?
d) Gain-Bandwidth product
Explanation: A TTL interface stage is always used with the operational amplifier. A device which requires higher accuracy often tend to depend on gain-bandwidth product.
The choice of amplifier for receiver accuracy is dependant on gain-bandwidth product.
8. The multiplication factor for the APD varies with the device temperature. State whether the given statement is true or false.
Explanation: Optimum multiplication factor is required for smooth voltage variance. The multiplication factor for APD varies with the device temperature thus making provision of fine control for bias voltage.
9. How many categories of dynamic gain equalizers are available?
Explanation: Dynamic gain equalizers are categorized into two types. These are single-channel and multichannel equalizers, thus providing operation using single or multiple wavelengths.
10. How many simultaneous channels can be provided in a band DGE(Dynamic gain equalizer)?
Explanation: Generally, eight channels are provided simultaneously in a band DGE. These are for the attenuation purpose of channels along with gain equalization.
Sanfoundry Global Education & Learning Series – Optical Communications.
To practice all areas of Optical Communications, here is complete set of 1000+ Multiple Choice Questions and Answers.