Page 92 - Circuit Analysis II with MATLAB Applications

Chapter 2 Resonance

1 ·
§
Y = G + j Z C – ---------
f = f 1 © 1 Z L ¹
1
1
3
§
= 10 – 3 + j2S u 490 u 10 u 7.96 u 10 – 9 – ------------------------------------------------------------------------- ·
© 3 – 6 ¹
2S u 490 u 10 u 12.73 u 10
Likewise,
1 ·
§
Y = G + j Z C – ---------
f = f 2 © 1 Z L ¹
1
1
3
§
= 10 – 3 + j2S u 510 u 10 u 7.96 u 10 – 9 – ------------------------------------------------------------------------- ·
© 3 – 6 ¹
2S u 510 u 10 u 12.73 u 10
We will use MATLAB to do the computations.
G=10^( 3); BC1=2*pi*490*10^3*7.96*10^( 9);...
BL1=1/(2*pi*490*10^3*12.73*10^( 6)); Y1=G+j*(BC1 BL1);...
BC2=2*pi*510*10^3*7.96*10^( 9); BL2=1/(2*pi*510*10^3*12.73*10^( 6));...
Y2=G+j*(BC2-BL2); fprintf(' \n'); fprintf('magY1 = %5.2e mho \t', abs(Y1));...
fprintf('magY2 = %5.2e mho \t', abs(Y2)); fprintf(' \n'); fprintf(' \n')
magY1 = 1.42e-003 mho magY2 = 1.41e-003 mho

We will use the following MATLAB code for the plot
f=100*10^3: 10^3: 1000*10^3; w=2*pi*f;...
G=10^( 3); C=7.96*10^( 9); L=12.73*10^( 6);...
BC=w.*C; BL=1./(w.*L); Y=G+j*(BC-BL); plot(f,abs(Y));...
xlabel('Frequency in Hz'); ylabel('Magnitude of Admittance');grid

The plot is shown below.

2-26 Circuit Analysis II with MATLAB Applications

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