The high-frequency response of a direct-coupled amplifier having a dc gain of -1000 V/V incorporates zeros at ∞and 104 rad/s (one at each frequency) and poles at 103 rad/s and 105 rad/s (one at each frequency). Write an expression for the amplifier transfer function. Find ωH using
(a) the dominant-pole approximation
(b) the root-sum-of-squares approximation (Eq. 10.77). If a way is found to lower the frequency of the finite zero to 103 rad/s, what does the transfer function become? What is the 3-dB frequency of the resulting amplifier?
ωH = 1/√((1/ω2p1 + 1/ω2p2 +...) - 2(1/ω2z1 + 1/ω2z2 +...))