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Antenna Reflection Problem

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blueblin

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hi all, for antenna reflection, Γ = (Za-Zo)/(Za+Zo). Assume Zo = 50Ω, Za = Ra + jXa.
What will be observed when Xa = 0? change of frequency?
 

vfone

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If Xa is zero, then the impedance of the antenna is purely resistive.
The resonant frequency will move in the opposite direction where the reactive impedance was (capacitive or inductive).
 

katko

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Uh, a constant Xa typically means a change in frequency...what's the question?

Impedance matching typically chooses an Xa so that Xa =0 so you can match the real Ra to Z0. As in a basic EM/Tline text. Is that your question, or something else? Typically you design a circuit so you cancel out Xa of the antenna, thus delivering max power to the antenna. Sorry if this is too basic, I'm not sure what you're asking beyond this.
 

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