
156 Network Analysis and Synthesis
4.4.2 Non-Ideal Tank Circuit
Now, we will consider the resonance in tank circuit by considering the resistance of the inductor
coil, as shown in Figure 4.14.
The equivalent inductance L
eq
and equivalent resistance r
eq
are given as follows:
LL
Q
Q
rQ
Q
X
eq eq
L
and =
+
=
2
2
2
1
1r
At parallel resonance, X
L(eq)
= X
C
.
The L–C branches act as an ideal tank. Since, current I = 0, the tank circuit will have infinite
impedance at resonance.
The total impedance of the circuit at resonance is equal to equivalent resistance r
eq
which
can be written as follows:
Z
r
= r
eq
(Q
2
+ 1)
4.4.3 Resonant Frequency
The resonant frequency ...