• Croquette
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    6 months ago

    As the distance increase between two surfaces, the capacitance diminishes and the voltage between the two increase, so that C=QV is always true.

    The resonant frequency is determined by the impedence, i.e. capacitive and inductive impedence.

    You can’t affect inductive impedance of the antenna because you are not a coil and do not emit EMR. But you can change the capacitance between you and the antenna by moving closer or further away.

    • piecat@lemmy.world
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      6 months ago
      1. as the distance increases the capacitance reduces. But C=Q/V doesn’t mean you’re not inducing any potential into the antenna… You’re adding to the load… C=ε*A/d is the equation that says capacitance will decrease with distance, but that isn’t going to induce any voltage in this case.

      2. yes this is what I’m saying.

      3. in the very near field, conductive tissue, ie a body, will have Eddy currents. Your body has an ε term as well as σ. You can definitely load an antenna. The R term will dominate but there will be some effect on inductance.