Figure 104 $g_{m 1}=g_{m 2}=$ $2.5 \mathrm{~mA} / \mathrm{V}, r_{o 1}=r_{o 2}=20 \mathrm{k} \Omega, C_{g s 1}=C_{g s 2}=$

Figure 10.4.1
For the cascode amplifier in Fig. 10.4.1 (with the dc bias circuitry not shown), $g_{m 1}=g_{m 2}=$ $2.5 \mathrm{~mA} / \mathrm{V}, r_{o 1}=r_{o 2}=20 \mathrm{k} \Omega, C_{g s 1}=C_{g s 2}=$ $20 \mathrm{fF}, C_{g d 1}=C_{g d 2}=5 \mathrm{fF}, C_{d b 1}=C_{d b 2}=5 \mathrm{fF}$ , $C_{L}=5 \mathrm{fF}$ , and $R_{\mathrm{sig}}=10 \mathrm{k} \Omega$ . Investigate two designs, one that results in a de gain of $60 \mathrm{~dB}$ and one that provides a dc gain of $40 \mathrm{~dB}$ . For each case, find the required value of $R_{L}$ , the resulting 3 -dB frequency $f_{H}$ , and the gain-bandwidth product. Comment on the tradeoff between gain and bandwidth.