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
=
b1 T21 T22 a2
T11 = 1 S21 , T21 = S11 S21 , etc.
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 variables
figure; % open new graph
% Normalized compon
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
conditions are difficult to enforce
RF implies forward an
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; % clear all variables
figure; % open new graph
% Normali
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
conditions are difficult to enforce
RF implies forward an
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 frequency is f U =
2.64 GHz.
EEE 194RF_L19
1
RF/W Stripline
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
Electrical performance inferior to other
implementatio
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 = 1 since unity gain.
And the order of the filter is N