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Help with Standing Wave Ratio calculation; Complex Quantity

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Abraham900

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Hello!

I'm new to this forum and I'm hoping I will get some help here.

I want to calculate the standing wave ratio for a wire with the characteristic impedande Z0 = 300 ohm. We will also apply a load with the complex impedance 150+j150.

Now, I do know how to calculate if the load is of pure resisitive character but I'm stuck with the complex part of the load.

There's a formula for SWR = (1 + |p|) / (1 - |p|).

I would be glad if I could get some help or explain some kind of theory to help me solve this problem.

Thanks!!
 

Dear Abraham

plot your normalized impedance value on the smithchart and draw a circle passing through that point with your centre at r=1 point and you have the vswr.

Best Regards
Sajid Mohammed.

---------- Post added at 18:37 ---------- Previous post was at 18:32 ----------

sorry didnt finish the complete answer. after you draw your circle,look at the point where it passes through the centre of the smith chart,measure the value using a scale and compare it with the length provided in the scale provided on the bottom.

Hope that helps

Best Regards
Chachito.
 
Of course!!!

Thanks!! Why didn't I think of the Smith Chart! Cheers and good day to you sir!
 

Cheers and Good Evening to my friend.

Regards
Sajid Mohammed.
 
This got me to think. The circle will cross two points at the Smith Chart. What point should I take?

Thanks once again.
 

the measurement is just the radius.it was a typo. radius of the circle is the length you should be looking at. from the centre to the edge if its one then comparison of the radius to the value from centre to edge gives you VSWR. or if you have a marked smith chart then look at the radius and compare the value on the scale provided below the smith chart.

Hope that helps

Best regards
Sajid Mohammed.
 
Yes, I understand. I was just a bit confused choosing between the left or right scale that is below the circle.

The answer is 2.6:1 :)

Have a nice day.
 

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