#### zia.newversion

##### Member level 5

I am taking a course of Antenna Theory and was looking around for some material for self study where I came across this problem.

It gives a table of Freq vs. Impedance (Imaginary and Real). Asks to plot on MATLAB. That was easy. Done!

Then tells to plot Voltage Reflection Coefficient by taking Z0=150 Ω. I figured it'd be

Γ = (ZL-Z0)/(ZL+Z0), while ZL is the Impedance given in the table. Done!

Then Power Reflection Coefficient... I think that must be square of magnitude of Voltage Reflection Coefficient. Done!

Then it says to plot VSWR. I searched over the internet and found on Wikipedia that

VSWR = (1+ρ)/(1-ρ) where ρ = |Γ|... That's done, too!

Then S11, which in my opinion should be 20log(Γ)... I did it that way. So that's over...

Now there is this last part that is bothering me.

It lists percent tolerable reflected powers (as 10%, 20% etc.) and asks to calculate bandwidth of antenna for each of these values... Now here is where I got lost. I can feel there is some relation, but I can't actually see it. Square root of percent reflected power should give magnitude of percent reflected voltage, but what next... How do I calculate bandwidth of antenna from there?

I need your help to find an answer to that problem as well as let me know if any of the previous concepts are wrong. Please help. Thank you.