Patent ID: 8692179
Filing Date: 2014-04-08
Classification: H04B

Abstract:
1. An optical communication system using grounded coplanar waveguide, comprising: a current buffer, coupled to a signal source, for receiving a current signal from the signal source and outputting the current signal after reducing capacitance effects of the signal source; and a transimpedance amplifier (TIA), having a first end, a second end and a shunt-shunt feedback circuit, for converting the current signal to a voltage signal, wherein the first end receives the current signal, the second end outputs the voltage signal, the shunt-shunt feedback circuit is coupled between the first end and the second end; a plurality of transmission lines, connecting the current buffer and the transimpedance amplifier; wherein the transmission lines of the optical communication system have grounded coplanar waveguide (GCPW) structures, the current buffer further comprises a first transistor, a second transistor, a third transistor, a fourth transistor, a first resistance, a second resistance, a third resistance and a peaking circuit, wherein a drain of the first transistor is coupled to the signal source, a source of the second transistor and a source of the third transistor, a drain of the second transistor is coupled to the first end of the first resistance and the TIA, a drain of the third transistor is coupled to the second resistance and a gate of the fourth transistor, a source of the fourth transistor is grounded through the peaking circuit, and a drain of the fourth transistor is coupled to a gate of the second transistor and the third resistance.