Working with S-parameters
For network computations it is easier to
convert from the S-matrix representation to
the chain scattering matrix notation
b1 S11
=
b2 S 21
S12 a1
S 22 a2
a1 T11 T12 b2
Example 5-3 p 229 MatLab Result:
Second Order Butterworth Low-Pass Filter w/ fc = 900 MHz
% Example 5-3 p 229: Butterworth Low-Pass Filter
%
close all; % close all opened graphs
clear all; % clear all
Scattering parameters
There is a need to establish well-defined
termination conditions in order to find the
network descriptions for Z, Y, h, and
ABCD networks
Open and short voltage and current
con
Example 5-3 p 229 MatLab Result:
Second Order Chebyshev Low-Pass Filter w/ 3 dB Ripple and fc = 900 MHz
% Example 5-3 p 229: Chebyshev Low-Pass Filter
close all; % close all opened graphs
clear all; %
Scattering parameters
There is a need to establish well-defined
termination conditions in order to find the
network descriptions for Z, Y, h, and
ABCD networks
Open and short voltage and current
con
Band-Pass Filter Design Example
Attenuation response
of a third-order 3-dB
ripple bandpass
Chebyshev filter
centered at 2.4 GHz.
The lower cut-off
frequency is f L = 2.16
GHz and the upper cutoff freq
Stepped Impedance Low-Pass Filter
Relatively easy (believe that?) low-pass
implementation
Uses alternating very high and very low
characteristic impedance lines
Commonly called Hi-Z, Low-Z Filters
Low-Pass Filter Design Example
Design a Low-Pass Filter with cut-off
frequency of 900 MHz and a stop band
attenuation of 18 dB @1.8 GHz.
From the Butterworth Nomograph, Amax = 1
and Amin = 18. Amax