Design And Research On SiGe Wideband Low Noise Amplifier And Laser Driver Integrated Circuit

As an indispensable high speed solid state devices of the microwave and millimeter wavefield, SiGe HBT (Silicon-Germanium Heterojunction Bipolar Transistor) has graduallydeveloped as a competitive technology with high power density and gain, low phase noise,good linearity, single supply, small chip area and high performance price ratio. As an essentialpart of the RF transceiver system and the optical fiber communication system, theperformance of the low noise amplifier especially wideband low noise amplifier whichsupports multiple protocols and laser driver has a great influence to the whole system,respectively. Therefore in the future, the study of the high performance wideband LNA andlaser driver with SiGe HBT process should be focus on in the two fields.According to the detailed analysis of the relative theory and technology of the widebandLNA and the laser driver, respectively. On the one hand, a SiGe HBT wideband LNA usingmultiple resistive feedback techniques was researched and designed. Firstly, the equivalentcircuit of the resistive feedback loops in the wideband LNA is derived according to thefeedback theory of the reference documentation. Then the expressions which reflected thephysical meaning of the voltage and current gain, input and output resistance, poles and thenoise figure of the wideband LNA were derived and used to guide the circuit simulation anddesign with the detailed theoretical derivation and analysis by using the simplifiedsmall-signal equivalent circuit. On the other hand, the main channel circuit of the laser driverwas researched and designed. The Push-Pull driving circuit and the output stage using thecross-coupled Miller capacitance cancellation technique were used to improve the bandwidthof the whole circuit and the speed of the signal.The two circuits were simulated and tested in SiGe HBT process provided by ShanghaiHua Hong Electronics Company. The IC was finally taped out after the layout optimizationand redesign. The detailed measurements of the wideband LNA using the nonlinear vectornetwork analyzer and the microwave probe station were tested. The measured results meet t hedesign requirements, with the small-signal power gain of33dB with3-dB bandwidth of3.3GHz, input and output VSWR better than2.0within3dB bandwidth, the noise figure lowerthan4.25dB from100MHz to6GHz, OP1dBof1.7dBm and OIP3of11dBm at3dB bandwidth,respectively. The comprehensive performance of the LNA chip has strong competitivenesscompared to many wideband LNAs which were reported with the advanced technologies athome and abroad.