Hi Chavadar,
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I ran a simple loop model in EZNEC Pro+ version 7.0. The simulated loop is an octagon with dimensions that approximate a one meter diameter circular loop. Conductor diameter is 3.3 mm. Excitation is a 1V/m plane wave. The loop was modeled in free space. A resistive load of 0.1 Ohms (essentially a short circuit) was placed across the feed-point. I also ran a simulation for feed-point impedance.
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RESULTS
? ? ? ? ? ?S.C.? ?SC Current
Freq? ? ?Current? ?rel.1MHz? ? ?R? ? ? ? ? X
(MHz)? ? ? (mA)? ? ? (dB)? ? ?(Ohms)? ? ?(Ohms)
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?1? ? ? ? 0.700 ? ? ?0.0 ? ? ? 0.0? ? ? ?23.6
?2? ? ? ? 0.700 ? ? ?0.0 ? ? ? 0.0? ? ? ?47.2
?3? ? ? ? 0.700 ? ? ?0.0 ? ? ? 0.0? ? ? ?70.9
?4 0.700 ? ? ?0.0 ? ? ? 0.0? ? ? ?94.7
?5 0.700 ? ? ?0.0 ? ? ? 0.0? ? ? 118.8
15? ? ? ? 0.707 ? ? ?0.1? ? ? ?0.2? ? ? 382.6
30? ? ? ? 0.713 ? ? ?0.2? ? ? ?6.1? ? ?1045.0
45 0.726 ? ? ?0.3? ? ?627.7? ? ?5527.5
46? ? ? ? 0.727 ? ? ?0.3? ? 1199.6? ? ?7280.1
47 0.728 ? ? ?0.3? ? 2815.0? ? 10472.0
48 0.729? ? ? 0.4? ? 9790.6? ? 16749.7
49? ? ? ? 0.730 ? ? ?0.4? ?35379.9? ? ? -48.7? <-- Resonance
50? ? ? ? 0.732 ? ? ?0.4? ?10458.9? ?-15201.0
51? ? ? ? 0.733 ? ? ?0.4? ? 3665.3? ? -9814.0
52? ? ? ? 0.734 ? ? ?0.4? ? 1872.4? ? -6931.7
53? ? ? ? 0.736 ? ? ?0.4? ? 1165.4? ? -5304.5
54? ? ? ? 0.737 ? ? ?0.5? ? ?814.8? ? -4276.0
55 0.739 ? ? ?0.5? ? ?614.4? ? -3570.1
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The short circuit current (i.e. the Norton equivalent source current) is constant within 0.2 dB up to 30MHz.? This is much flatter than I would have expected.? I was equally surprised that the short circuit current at resonance was only 0.4dB higher than the value at low frequencies.? I have not used this software much but I believe I did everything right.
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I will upload the simulation file to Files.
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- Mark
