Design Transfer impedance amplifier circuit with low power consumption and high bandwidth for Optical communication applications

摘要

Nowadays, use of optical communications is widely used in data transmission applications at near and far distances. The main parts of an optical communication system includes a transmitter, channel and receiver which the design and construction of each of these parts have their own problems and challenges. Since the optical data sent from the transmitter to the receiver have been found with large deficits such as weakness, noise, distortion, diffraction, interference, etc. design of the receiver has faced further challenges. The receiver consists of different parts including an optical detector, amplifier, filter, circuit decision and etc. The task of optical signals is converting optical signal into electrical signals. Amplifier which develops the most important part of optical receivers amplifies the signal generated through optical detector. The optics emitted through an optical fiber has been incurred large losses before reaching to the optical detector in receiver part. Then optical detector converts light intensity to a current proportional to the light intensity, which subsequently it has been amplified via a Trans-Impedance Amplifier (TIA) and converted to the voltage. However, the signal generated in the output of TIA has usually small amplitude in about several tens of millivolts. So after class TIA, another amplifier class should be used to increase signal fluctuations in the reasonable levels, i.e. in range of 500 mV. An amplifier that is used for this purpose is called Limiting Amplifier shown with LA. LA has large output fluctuations in addition to generation of High voltage gain. This research aims to design LA and TIA in a way to reduce the consumed power as much as possible by creating gain and suitable bandwidth to transfer data at a rate of 2.5 Gb/s.