5. 2GHz MONOLITHIC GaAs OPTOELECTRONIC RECEIVER.

Abstract

The receiver consists of an interdigitated Schottky-barrier photodiode integrated with a GaAs transimpedance amplifier. The amplifier has an enhancement-driver/depletion-load input stage connected to a source follower matched to 50 OMEGA . The circuit is implemented with 0. 35- mu m recessed-gate GaAs MESFETs. The receiver is fully DC-coupled and is compatible with E/D (enhancement/depletion) MESFET logic circuits. A bandwidth of 5. 2 GHz was obtained for an effective transimpedance into a 50- OMEGA load of 300- OMEGA , yielding a transimpedance-bandwidth product of 1. 5 THz- OMEGA . A single photodiode was also fabricated within a 100- OMEGA transmission line. The photodiode exhibits an impulse response with FWHM (full width, half maximum) of only 4. 8 ps generated by a 1. 8-ps optical pulse.