This problem investigates the frequency response of the CS amplifi er to a source with a low resistance Rsig, ideally Rsig → 0. (a) Redraw the high-frequency equivalent of Fig. 6.15b, but with Rsig 5...

This problem investigates the frequency response of the CS amplifi er to a source with a low resistance Rsig, ideally Rsig → 0. (a) Redraw the high-frequency equivalent of Fig. 6.15b, but with Rsig 5 0, and also add a load capacitance CL in parallel with RD for a more general analysis. Writing a node equation at the output node, show that

indicating that the pole frequency is now established by the net resistance and capacitance of the output (rather than the input) node. (b) Investigate the specifi c case of a FET with gm 5 1.8 mA/V, ro 5 50 kV, and Cgd 5 0.5 pF, driving RD 5 10 kV and CL 5 2 pF. (c) Sketch and label the Bode plot of gain, and estimate the GBP of this amplifi er.