0195136047.pdf

3.6 USE OF MATLAB IN COMPUTER-AIDED CIRCUIT SIMULATION 173

• AC DEC 20 10 HZ 100KHZ

• ANALYSIS EXTENDS FROM TWO DECADES BELOW TO TWO DECADES ABOVE
  1 KHZ, THAT IS, FROM 10 HZ TO 100 KHZ.

• PROBE

• RESULTS ARE SAVED FOR DISPLAY BY THE PROBE PROGRAM

• END
  Figures E3.5.3(b) and (c) display the magnitude and phase plots. Note that the filter gain is nearly
  0 dB for frequencies above 1 kHz and falls at the rate of 40 dB per decade for frequencies below
  1 kHz.

3.6 Use of MATLAB in Computer-Aided Circuit Simulation

We shall illustrate the use of MATLAB by considering the following three examples.

EXAMPLE 3.6.1

This example is concerned withsteady-state sinusoidal analysisby using mesh equations and

MATLAB. Let us consider the circuit shown in Figure E3.6.1 and find the input impedance at the

input interface terminalsA–Band the ratioV ̄O/V ̄S.

−

+

−

+

Vs = 10 ∠ 0 °

Zin

IA IB

IC

ZC 1 ZC 2

ZL 2 RL VO

A

B

Rs = 50 Ω

ZL 1 = j 100 Ω

−j 50 Ω−j 50 Ω

j 100 Ω 50 Ω

Figure E3.6.1

Solution

Note that

Z ̄IN=

V ̄S

I ̄A

−RS and K ̄=

V ̄O

V ̄S

=

RLI ̄B

V ̄S

The M-file and answers are as follows:

function example361

clc

% Circuit Parameters

RS = 50;

RL = 50;

VS = 10;