The Effects of a Feedback Capacitor in a Optical Receiver Designed with Transimpedance Amplifier

Abstract

Kertas teknikal ini melaporkan kesan penambahan satu kapasitor suap balik di dalam penerima opto–elektrik menggunakan penguat transgalangan (TIA). TIA digunakan di dalam penerima untuk menyokong kedua–dua kelajuan dan gandaan tinggi. Walau bagaimanapun, satu masalah yang dihadapi apabila membina penerima dengan TIA iaitu gandaan memuncak menghasilkan output yang tidak stabil. Satu pendekatan mudah iaitu meletakkan satu kapasitor suap balik dalam litar penguat didapati telah mengurangkan puncak tersebut dari 2 dB ke 0 dB. Kata kunci: Optik, penerima, transgalangan, penguat, suap balik, kapasitor, gandaan, puncak This paper reports the effect of adding a feedback capacitor in the opto–electrical receiver with a transimpedance amplifier (TIA).A TIA is used in a receiver to provide for both high speed and high gain. However, there is a problem faced when developing a receiver with TIA; gain peaking, which creates an unstable output. A simple approach of placing a feedback capasitor on the amplifier was found to reduce the peaking from 2 dB down to 0 dB. Key words: Optical, receiver, transimpedance, amplifier, feedback, capacitor, gain, peaking