A 3-stage dual TransImpedance Ampffier (TIA) on one 2x7.8 mm2 GaAs chip with 0.2 pm pHEMT technologt has been designed for fiberoptic communication applications. It uses cascode connected common source FETs in a Constant-K configuration. The operating frequency ranges from DC to 3 5 GHz, The TIA is desígned for a diode capacítance of 120 fF. The equívøaent input refrred noise current is around 18 pA/\/Hz for a gaín of øround 40 dBQ or 6.5 dB. The møtching øt the out¡tut ß better than 14 dB, Measured RF performance in combination wíth the small size makes it very saitable for WDM telecommunìcation systems. A comparìson between simulations and measurements ìs also made.