mi3.nec

zip contains tool for Antenna Modelling with examples

CM VE9SRB - MI3 Fractal Loop, converted with 4nec2 on 30-Mar-06 20:18
CM This is the VE9SRB version of the MI3 fractal loop antenna.
CM  The design concept was presented by Dr. Nathan Cohen
CM (N1IR) in several Communications Quarterly articles.  It is
CM also discussed, and clearly illustrated in one of his
CM patents.
CM This particular version of the MI3 fractal loop was
CM independently created and proportioned from my existing MI2
CM file.  I tried to keep the antenna within the overall size
CM of the MI2 fractal loop.  The MI3 is about 2.77 m by 2.6 m
CM while the MI2 is 2.8 m by 2.66 m.  The MI2 has a total wire
CM length of about 27.6 m while the MI3 has about 45.7 m of
CM wire.   I cannot compare these proportions with the N1IR
CM MI3 as I do not have access to his EZNEC file.  I do not
CM expect the proportions to be the same, although performance
CM should be somewhat similar.
CM This loop has two principal resonances, one at 11.48 Mhz
CM and one at 21.83 Mhz.  These are lower than the MI2
CM resonances, primarily a result of the increase in total
CM wire length in the structure.  The resistance at these
CM resonances is 17.6 and 9.6 ohms, respectively, which is
CM somewhat consistent with the N1IR results.  It is my
CM opinion that my MI3 has slightly more wire than the N1IR
CM version, causing the resonant frequency to be somewhat
CM lower.
CM One interesting point to note is the calculated gain of the
CM MI3 versus the MI2.  In his CQ articles, N1IR claims that
CM these fractal loops have high efficiency and gain at low
CM frequencies.  I find that this is not the case.  As an
CM example, N1IR quotes the gain for both the MI2 and the MI3
CM to be exactly the same at their resonant frequencies, 2.0
CM and 4.0 dBi, respectively.  Given that the MI3 has
CM significantly more wire than the MI2, this should not be
CM true.  My gain calculations are consistent with the
CM increase in wire length, where the MI3 has 1.0 dBi and 2.1
CM dBi gain, at its respective resonances.   Additionally, a
CM graph of gain vs frequency presented by N1IR indicates that
CM as frequency is decreased the gain of these loops does not
CM fall below 1.5 dBi.  Examining both the MI2 and the MI3
CM with decreasing frequency, it is evident that both
CM efficiency and gain drop off dramatically.
CM For additional validation of the resonant gain and
CM resistance performance of the MI3, a modified MI3 was
CM designed having less overall total wire.  As a result, it
CM is expected that the resonant frequency, gain and
CM resistance will increase.  These results are presented in
CM the MI3Mod.ez file.
CE
GW 1 1 0.05198 0.08856 0 0.05198 0.157867 0 1.6e-3
GW 2 1 0.05198 0.157867 0 0.14439 0.157867 0 1.6e-3
GW 3 1 0.14439 0.157867 0 0.14439 0.257978 0 1.6e-3
GW 4 1 0.14439 0.257978 0 0.229099 0.257978 0 1.6e-3
GW 5 1 0.229099 0.257978 0 0.229099 0.350388 0 1.6e-3
GW 6 1 0.229099 0.350388 0 0.14439 0.350388 0 1.6e-3
GW 7 1 0.14439 0.350388 0 0.14439 0.446649 0 1.6e-3
GW 8 1 0.14439 0.446649 0 0.250662 0.446649 0 1.6e-3
GW 9 1 0.250662 0.446649 0 0.250662 0.36964 0 1.6e-3
GW 10 1 0.250662 0.36964 0 0.349232 0.36964 0 1.6e-3
GW 11 1 0.349232 0.36964 0 0.349232 0.446649 0 1.6e-3
GW 12 1 0.349232 0.446649 0 0.441643 0.446649 0 1.6e-3
GW 13 1 0.441643 0.446649 0 0.441643 0.512106 0 1.6e-3
GW 14 1 0.441643 0.512106 0 0.534053 0.512106 0 1.6e-3
GW 15 1 0.534053 0.512106 0 0.534053 0.604516 0 1.6e-3
GW 16 1 0.534053 0.604516 0 0.441643 0.604516 0 1.6e-3
GW 17 1 0.441643 0.604516 0 0.441643 0.712328 0 1.6e-3
GW 18 1 0.441643 0.712328 0 0.557155 0.712328 0 1.6e-3
GW 19 1 0.557155 0.712328 0 0.557155 0.63917 0 1.6e-3
GW 20 1 0.557155 0.63917 0 0.664967 0.63917 0 1.6e-3
GW 21 1 0.664967 0.63917 0 0.664967 0.712328 0 1.6e-3
GW 22 1 0.664967 0.712328 0 0.741975 0.712328 0 1.6e-3
GW 23 1 0.741975 0.712328 0 0.741975 0.820139 0 1.6e-3
GW 24 1 0.741975 0.820139 0 0.822834 0.820139 0 1.6e-3
GW 25 1 0.822834 0.820139 0 0.822834 0.893297 0 1.6e-3
GW 26 1 0.822834 0.893297 0 0.741975 0.893297 0 1.6e-3
GW 27 1 0.741975 0.893297 0 0.741975 1.001109 0 1.6e-3
GW 28 1 0.741975 1.001109 0 0.664967 1.001109 0 1.6e-3
GW 29 1 0.664967 1.001109 0 0.664967 1.074267 0 1.6e-3
GW 30 1 0.664967 1.074267 0 0.557155 1.074267 0 1.6e-3
GW 31 1 0.557155 1.074267 0 0.557155 1.001109 0 1.6e-3
GW 32 1 0.557155 1.001109 0 0.441643 1.001109 0 1.6e-3
GW 33 1 0.441643 1.001109 0 0.441643 1.108921 0 1.6e-3
GW 34 1 0.441643 1.108921 0 0.534053 1.108921 0 1.6e-3
GW 35 1 0.534053 1.108921 0 0.534053 1.201331 0 1.6e-3
GW 36 1 0.534053 1.201331 0 0.441643 1.201331 0 1.6e-3
GW 37 1 0.441643 1.201331 0 0.441643 1.297591 0 1.6e-3
GW 38 1 0.441643 1.297591 0 0.564856 1.297591 0 1.6e-3
GW 39 1 0.564856 1.297591 0 0.564856 1.220583 0 1.6e-3
GW 40 1 0.564856 1.220583 0 0.663427 1.220583 0 1.6e-3
GW 41 1 0.663427 1.220583 0 0.663427 1.297591 0 1.6e-3
GW 42 1 0.663427 1.297591 0 0.769698 1.297591 0 1.6e-3
GW 43 1 0.769698 1.297591 0 0.769698 1.201331 0 1.6e-3
GW 44 1 0.769698 1.201331 0 0.684989 1.201331 0 1.6e-3
GW 45 1 0.684989 1.201331 0 0.684989 1.108921 0 1.6e-3
GW 46 1 0.684989 1.108921 0 0.769698 1.108921 0 1.6e-3
GW 47 1 0.769698 1.108921 0 0.769698 1.00881 0 1.6e-3
GW 48 1 0.769698 1.00881 0 0.862108 1.00881 0 1.6e-3
GW 49 1 0.862108 1.00881 0 0.862108 0.939502 0 1.6e-3
GW 50 1 0.862108 0.939502 0 0.96607 0.939502 0 1.6e-3
GW 51 1 0.96607 0.939502 0 0.96607 1.00881 0 1.6e-3
GW 52 1 0.96607 1.00881 0 1.05848 1.00881 0 1.6e-3
GW 53 1 1.05848 1.00881 0 1.05848 1.108921 0 1.6e-3
GW 54 1 1.05848 1.108921 0 1.143189 1.108921 0 1.6e-3
GW 55 1 1.143189 1.108921 0 1.143189 1.201331 0 1.6e-3
GW 56 1 1.143189 1.201331 0 1.05848 1.201331 0 1.6e-3
GW 57 1 1.05848 1.201331 0 1.05848 1.297591 0 1.6e-3
GW 58 1 1.05848 1.297591 0 1.164751 1.297591 0 1.6e-3
GW 59 1 1.164751 1.297591 0 1.164751 1.220583 0 1.6e-3
GW 60 1 1.164751 1.220583 0 1.263322 1.220583 0 1.6e-3
GW 61 1 1.263322 1.220583 0 1.263322 1.297591 0 1.6e-3
GW 62 1 1.263322 1.297591 0 1.386535 1.297591 0 1.6e-3
GW 63 1 1.386535 1.297591 0 1.386535 1.201331 0 1.6e-3
GW 64 1 1.386535 1.201331 0 1.294125 1.201331 0 1.6e-3
GW 65 1 1.294125 1.201331 0 1.294125 1.108921 0 1.6e-3
GW 66 1 1.294125 1.108921 0 1.386535 1.108921 0 1.6e-3
GW 67 1 1.386535 1.108921 0 1.386535 1.001109 0 1.6e-3
GW 68 1 1.386535 1.001109 0 1.271023 1.001109 0 1.6e-3
GW 69 1 1.271023 1.001109 0 1.271023 1.074267 0 1.6e-3
GW 70 1 1.271023 1.074267 0 1.163211 1.074267 0 1.6e-3
GW 71 1 1.163211 1.074267 0 1.163211 1.001109 0 1.6e-3
GW 72 1 1.163211 1.001109 0 1.086203 1.001109 0 1.6e-3
GW 73 1 1.086203 1.001109 0 1.086203 0.893297 0 1.6e-3
GW 74 1 1.086203 0.893297 0 1.005344 0.893297 0 1.6e-3
GW 75 1 1.005344 0.893297 0 1.005344 0.820139 0 1.6e-3
GW 76 1 1.005344 0.820139 0 1.086203 0.820139 0 1.6e-3
GW 77 1 1.086203 0.820139 0 1.086203 0.712328 0 1.6e-3
GW 78 1 1.086203 0.712328 0 1.163211 0.712328 0 1.6e-3
GW 79 1 1.163211 0.712328 0 1.163211 0.63917 0 1.6e-3
GW 80 1 1.163211 0.63917 0 1.271023 0.63917 0 1.6e-3
GW 81 1 1.271023 0.63917 0 1.271023 0.712328 0 1.6e-3
GW 82 1 1.271023 0.712328 0 1.386535 0.712328 0 1.6e-3
GW 83 1 1.386535 0.712328 0 1.386535 0.604516 0 1.6e-3
GW 84 1 1.386535 0.604516 0 1.294125 0.604516 0 1.6e-3
GW 85 1 1.294125 0.604516 0 1.294125 0.512106 0 1.6e-3
GW 86 1 1.294125 0.512106 0 1.386535 0.512106 0 1.6e-3
GW 87 1 1.386535 0.512106 0 1.386535 0.415845 0 1.6e-3
GW 88 1 1.386535 0.415845 0 1.263322 0.415845 0 1.6e-3
GW 89 1 1.263322 0.415845 0 1.263322 0.492854 0 1.6e-3
GW 90 1 1.263322 0.492854 0 1.164751 0.492854 0 1.6e-3
GW 91 1 1.164751 0.492854 0 1.164751 0.415845 0 1.6e-3
GW 92 1 1.164751 0.415845 0 1.05848 0.415845 0 1.6e-3
GW 93 1 1.05848 0.415845 0 1.05848 0.512106 0 1.6e-3
GW 94 1 1.05848 0.512106 0 1.143189 0.512106 0 1.6e-3
GW 95 1 1.143189 0.512106 0 1.143189 0.604516 0 1.6e-3
GW 96 1 1.143189 0.604516 0 1.05848 0.604516 0 1.6e-3
GW 97 1 1.05848 0.604516 0 1.05848 0.704627 0 1.6e-3
GW 98 1 1.05848 0.704627 0 0.96607 0.704627 0 1.6e-3
GW 99 1 0.96607 0.704627 0 0.96607 0.773934 0 1.6e-3
GW 100 1 0.96607 0.773934 0 0.862108 0.773934 0 1.6e-3
GW 101 1 0.862108 0.773934 0 0.862108 0.704627 0 1.6e-3
GW 102 1 0.862108 0.704627 0 0.769698 0.704627 0 1.6e-3
GW 103 1 0.769698 0.704627 0 0.769698 0.604516 0 1.6e-3
GW 104 1 0.769698 0.604516 0 0.684989 0.604516 0 1.6e-3
GW 105 1 0.684989 0.604516 0 0.684989 0.512106 0 1.6e-3
GW 106 1 0.684989 0.512106 0 0.769698 0.512106 0 1.6e-3
GW 107 1 0.769698 0.512106 0 0.769698 0.415845 0 1.6e-3
GW 108 1 0.769698 0.415845 0 0.663427 0.415845 0 1.6e-3
GW 109 1 0.663427 0.415845 0 0.663427 0.492854 0 1.6e-3
GW 110 1 0.663427 0.492854 0 0.564856 0.492854 0 1.6e-3
GW 111 1 0.564856 0.492854 0 0.564856 0.415845 0 1.6e-3
GW 112 1 0.564856 0.415845 0 0.472446 0.415845 0 1.6e-3
GW 113 1 0.472446 0.415845 0 0.472446 0.350388 0 1.6e-3
GW 114 1 0.472446 0.350388 0 0.380036 0.350388 0 1.6e-3
GW 115 1 0.380036 0.350388 0 0.380036 0.257978 0 1.6e-3
GW 116 1 0.380036 0.257978 0 0.472446 0.257978 0 1.6e-3
GW 117 1 0.472446 0.257978 0 0.472446 0.150166 0 1.6e-3
GW 118 1 0.472446 0.150166 0 0.356933 0.150166 0 1.6e-3
GW 119 1 0.356933 0.150166 0 0.356933 0.223324 0 1.6e-3
GW 120 1 0.356933 0.223324 0 0.249122 0.223324 0 1.6e-3
GW 121 1 0.249122 0.223324 0 0.249122 0.150166 0 1.6e-3
GW 122 1 0.249122 0.150166 0 0.172113 0.150166 0 1.6e-3
GW 123 1 0.172113 0.150166 0 0.172113 0.042355 0 1.6e-3
GW 124 1 0.172113 0.042355 0 0.091254 0.042355 0 1.6e-3
GW 125 1 0.091254 0.042355 0 0.091254 -0.042355 0 1.6e-3
GW 126 1 0.091254 -0.042355 0 0.172113 -0.042355 0 1.6e-3
GW 127 1 0.172113 -0.042355 0 0.172113 -0.150166 0 1.6e-3
GW 128 1 0.172113 -0.150166 0 0.249122 -0.150166 0 1.6e-3
GW 129 1 0.249122 -0.150166 0 0.249122 -0.223324 0 1.6e-3
GW 130 1 0.249122 -0.223324 0 0.356933 -0.223324 0 1.6e-3
GW 131 1 0.356933 -0.223324 0 0.356933 -0.150166 0 1.6e-3
GW 132 1 0.356933 -0.150166 0 0.472446 -0.150166 0 1.6e-3
GW 133 1 0.472446 -0.150166 0 0.472446 -0.257978 0 1.6e-3
GW 134 1 0.472446 -0.257978 0 0.380036 -0.257978 0 1.6e-3
GW 135 1 0.380036 -0.257978 0 0.380036 -0.350388 0 1.6e-3
GW 136 1 0.380036 -0.350388 0 0.472446 -0.350388 0 1.6e-3
GW 137 1 0.472446 -0.350388 0 0.472446 -0.415845 0 1.6e-3
GW 138 1 0.472446 -0.415845 0 0.564856 -0.415845 0 1.6e-3