
15.1 CIRCUIT RESPONSE TO COMPLEX EXPONENTIAL INPUT
Let the n
th
order differential equation describing a n
th
order linear time-invariant circuit be
(15.1-1)
y(t) is some circuit variable identified as the output variable and x(t) is some independent
voltage/current source function. Let x(t) 1 e
st
be a complex exponential function of unit
amplitude and complex frequency s
σ
+ j
ω
. Let y(t) A e
st
be the trial solution where A is
a complex number to be determined. Substituting the trial solution in Eqn. 15.1-1, we get,
Thus, when the input to a linear time-invariant circuit is a complex exponential
function e
st
, the output is the same complex exponential ...