GaAs MMIC variable gain optical receiver having an external open loop Automatic Gain control circuit

This work describes a 50MHz to 1050MHz fiber optic receiver design. This receiver is designed to be used in the CATV distribution network FTTX application. The MMIC portion is made of GaAs PHEMT, it consists of two amplification push pull stages separated by a voltage controlled variable attenuator stage. Responsivity of 27dBA/W with a gain variation of up to 20dB has been achieved. The circuit consumes less than 2Watts, the area is 3 mm² and has packaged in a low cost 28 pin leedless package.