
450 Network Analysis and Synthesis
10.12 STABILITY CRITERION FOR AN ACTIVE NETWORK
A network is said to be stable only when all the poles lie on the left half of the s-plane. The
location of the poles provides an idea about the stability of the network. Let us consider the
denominator polynomial of the network function. The denominator when equated to zero gives
the characteristic equation,
Q(s) = b
0
s
m
+ b
1
s
m-1
+
…
+ b
m
According to Routh Stability Criterion, for a stable system, all the roots of the characteristic
equation must have negative real parts. There should not be any positive pole.
It should, however, be noted that simply by having ...