A 2-38 GHz Linear GaAs pHEMT TIA for a Quasi-Coherent Optical Receiver

This paper presents the design and testing of a linear transimpedance amplifier (TIA) in a GaAs pHEMT technology. The TIA has been developed for integration within an optical receiver using a quasi-coherent technology. The maximum measured differential transimpedance is 63 dB Omega, with a 3 dB operating frequency range from 2 to 38 GHz. The group delay variation is within +/- 10 ps from 5 to 32 GHz, and the maximum input current for linear operation is 2 mA peak-to-peak at the 1 dB compression point.