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In which direction we need to go and read the reflection coefficient angles.

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pusparaga

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I need to find reflection coefficient angle = 300 degree using Smith chart. In which direction I need to go and find the angle 300 degree. There in Smith chart, they specified 0 to ± 180 degree, how to find 300 degree reflection coefficient angle using smith chart, please guide me. Herewith I attached Smith Chart angle diagram.
 

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  • Smith_Chart.jpg
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Problem is as follows
A 70 Ohm lossless line has s = 1.6 and reflection coefficient angle =300 degree. If the line is 0.6 lamda long, obtain (i) Reflection coefficient , Load impedance, and input impedance.
Answer is as follows, In the following image, he has taken 300 degree at "OQ" (marked it as 300 degree). How he took 300 degree, I am not understanding. Please tell how to take angles in Smith chart and how he marked 300 degree, it is correct only. Explain in elaborately.
 

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pusparaga said:
Problem is as follows
Click to expand...
It is too easy.

Can you understand basic complex algebra and transmission line theory ?

Code: 
% https://www.edaboard.com/showthread.php?379848
% In-which-direction-we-need-to-go-and-read-the-reflection-coefficient-angles.

close all, clear all, clc
set(0, 'language', 'english')
colordef white; % Specify the plot background to be white

set(gcf, 'numbertitle', 'off')
set(gcf, 'MenuBar', 'none')

Rc = 70;

%S0 = 0.228 * exp(j*pi*300/180)
S0 = 0.228 * exp(j*pi*(-60)/180) % Point P

z0 = (1+S0) / (1-S0)
Z0 = Rc * z0

%beta = 2*pi/lambda
%L = 0.6*lambda
%S1 = S0 * exp(-j*2*beta*L)
%S1 = S0 * exp(-j*pi*432/180)
%S1 = 0.228 * exp(j*pi*(-492)/180)
S1 = 0.228 * exp(j*pi*(-132)/180) % Point R

z1 = (1+S1) / (1-S1)
Z1 = Rc * z1

S0_hid = smithchart(S0);
hold on
S1_hid = smithchart(S1);

legend('P', 'Q')

set(S0_hid, 'Marker', 'o')
set(S0_hid, 'MarkerSize', 6)
set(S0_hid, 'LineStyle', 'none')
set(S0_hid, 'MarkerFaceColor', 'r')
set(S0_hid, 'MarkerEdgeColor', 'r')

set(S1_hid, 'Marker', 'o')
set(S1_hid, 'MarkerSize', 6)
set(S1_hid, 'LineStyle', 'none')
set(S1_hid, 'MarkerFaceColor', 'b')
set(S1_hid, 'MarkerEdgeColor', 'b')

colordef black; % Specify the plot background to be black

Code: 
S0 = 0.1140 - 0.1975i
z0 = 1.1505 - 0.4793i
Z0 = 80.5369 -33.5486i

S1 = -0.1526 - 0.1694i
z1 = 0.6986 - 0.2497i
Z1 = 48.8989 -17.4792i
 

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    180904-201744.png
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Last edited:

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