NEC-LIST: Helix antenna on ground plane

From: Ooi SooLiam-CSO005 (pen) <CSO005_at_email.domain.hidden>
Date: Fri, 26 Jun 1998 11:15:18 +0800

Hi all,

I am trying to model a helix antenna on a ground plane using MININEC
pro for windows.

I approximated each turn with 6 wires and made a 130 turn, 5 cm high
helix with 1.2 cm diameter. The impedance across the frequency is
very large and I can't see a resonance. Can anyone tell me what is
wrong with my model?

regards,
Sooliam

Here is the summary of the model

Number of wires = 180
          current nodes = 180

                        minimum maximum
Individual wires wire value wire value
segment length 160 .605757E+00 125 .605767E+00
segment/radius ratio 160 605.7573 125 605.7672
radius 1 .1E-02 1 .1E-02

ELECTRICAL DESCRIPTION
Frequencies (MHz)
     frequency no. of segment length (wavelengths)
 no. lowest step steps minimum maximum
 1 10. 10. 50 .101027E-01 .202057E-03

Sources
source node sector magnitude phase type
 1 1 1 1. 0 voltage

GEOMETRY
Dimensions in centimeters
Environment: PERFECT GROUND

wire caps X Y Z radius segs
 1 none .6E+00 0 0 .1E-02 1
           .3E+00 .519615E+00 .833333E-01
 2 none .3E+00 .519615E+00 .833333E-01 .1E-02 1
           -.3E+00 .519615E+00 .166667E+00
 3 none -.3E+00 .519615E+00 .166667E+00 .1E-02 1
           -.6E+00 -.524537E-07 .25E+00
 4 none -.6E+00 -.524537E-07 .25E+00 .1E-02 1
           -.3E+00 -.519615E+00 .333333E+00
 5 none -.3E+00 -.519615E+00 .333333E+00 .1E-02 1
           .3E+00 -.519615E+00 .416667E+00
 6 none .3E+00 -.519615E+00 .416667E+00 .1E-02 1
           .6E+00 .104907E-06 .5E+00
 7 none .6E+00 .104907E-06 .5E+00 .1E-02 1
           .3E+00 .519615E+00 .583333E+00
 8 none .3E+00 .519615E+00 .583333E+00 .1E-02 1
           -.3E+00 .519615E+00 .666667E+00
 9 none -.3E+00 .519615E+00 .666667E+00 .1E-02 1
           -.6E+00 -.143099E-07 .75E+00
 10 none -.6E+00 -.143099E-07 .75E+00 .1E-02 1
           -.3E+00 -.519615E+00 .833333E+00
 11 none -.3E+00 -.519615E+00 .833333E+00 .1E-02 1
           .3E+00 -.519615E+00 .916667E+00
 12 none .3E+00 -.519615E+00 .916667E+00 .1E-02 1
           .6E+00 .209815E-06 1.
 13 none .6E+00 .209815E-06 1. .1E-02 1
           .3E+00 .519615E+00 1.083333
 14 none .3E+00 .519615E+00 1.083333 .1E-02 1
           -.3E+00 .519615E+00 1.166667
 15 none -.3E+00 .519615E+00 1.166667 .1E-02 1
           -.6E+00 -.405319E-06 1.25
 16 none -.6E+00 -.405319E-06 1.25 .1E-02 1
           -.3E+00 -.519615E+00 1.333333
 17 none -.3E+00 -.519615E+00 1.333333 .1E-02 1
           .3E+00 -.519615E+00 1.416667
 18 none .3E+00 -.519615E+00 1.416667 .1E-02 1
           .6E+00 .286197E-07 1.5
 19 none .6E+00 .286197E-07 1.5 .1E-02 1
           .3E+00 .519615E+00 1.583333
 20 none .3E+00 .519615E+00 1.583333 .1E-02 1
           -.3E+00 .519615E+00 1.666667
 21 none -.3E+00 .519615E+00 1.666667 .1E-02 1
           -.6E+00 -.796329E-06 1.75
 22 none -.6E+00 -.796329E-06 1.75 .1E-02 1
           -.299999E+00 -.519616E+00 1.833333
 23 none -.299999E+00 -.519616E+00 1.833333 .1E-02 1
           .3E+00 -.519615E+00 1.916667
 24 none .3E+00 -.519615E+00 1.916667 .1E-02 1
           .6E+00 .419629E-06 2.
 25 none .6E+00 .419629E-06 2. .1E-02 1
           .3E+00 .519615E+00 2.083333
 26 none .3E+00 .519615E+00 2.083333 .1E-02 1
           -.3E+00 .519615E+00 2.166667
 27 none -.3E+00 .519615E+00 2.166667 .1E-02 1
           -.6E+00 -.429296E-07 2.25
 28 none -.6E+00 -.429296E-07 2.25 .1E-02 1
           -.299999E+00 -.519616E+00 2.333333
 29 none -.299999E+00 -.519616E+00 2.333333 .1E-02 1
           .300001E+00 -.519615E+00 2.416667
 30 none .300001E+00 -.519615E+00 2.416667 .1E-02 1
           .6E+00 .810639E-06 2.5
 31 none .6E+00 .810639E-06 2.5 .1E-02 1
           .3E+00 .519615E+00 2.583333
 32 none .3E+00 .519615E+00 2.583333 .1E-02 1
           -.3E+00 .519615E+00 2.666667
 33 none -.3E+00 .519615E+00 2.666667 .1E-02 1
           -.6E+00 -.157835E-05 2.75
 34 none -.6E+00 -.157835E-05 2.75 .1E-02 1
           -.3E+00 -.519615E+00 2.833333
 35 none -.3E+00 -.519615E+00 2.833333 .1E-02 1
           .300001E+00 -.519615E+00 2.916667
 36 none .300001E+00 -.519615E+00 2.916667 .1E-02 1
           .6E+00 .572394E-07 3.
 37 none .6E+00 .572394E-07 3. .1E-02 1
           .299999E+00 .519616E+00 3.083333
 38 none .299999E+00 .519616E+00 3.083333 .1E-02 1
           -.3E+00 .519615E+00 3.166667
 39 none -.3E+00 .519615E+00 3.166667 .1E-02 1
           -.6E+00 -.824949E-06 3.25
 40 none -.6E+00 -.824949E-06 3.25 .1E-02 1
           -.3E+00 -.519615E+00 3.333333
 41 none -.3E+00 -.519615E+00 3.333333 .1E-02 1
           .300001E+00 -.519615E+00 3.416667
 42 none .300001E+00 -.519615E+00 3.416667 .1E-02 1
           .6E+00 .159266E-05 3.5
 43 none .6E+00 .159266E-05 3.5 .1E-02 1
           .3E+00 .519615E+00 3.583333
 44 none .3E+00 .519615E+00 3.583333 .1E-02 1
           -.300001E+00 .519615E+00 3.666667
 45 none -.300001E+00 .519615E+00 3.666667 .1E-02 1
           -.6E+00 -.715493E-07 3.75
 46 none -.6E+00 -.715493E-07 3.75 .1E-02 1
           -.299999E+00 -.519616E+00 3.833333
 47 none -.299999E+00 -.519616E+00 3.833333 .1E-02 1
           .3E+00 -.519615E+00 3.916667
 48 none .3E+00 -.519615E+00 3.916667 .1E-02 1
           .6E+00 .839259E-06 4.
 49 none .6E+00 .839259E-06 4. .1E-02 1
           .299998E+00 .519616E+00 4.083333
 50 none .299998E+00 .519616E+00 4.083333 .1E-02 1
           -.300001E+00 .519615E+00 4.166667
 51 none -.300001E+00 .519615E+00 4.166667 .1E-02 1
           -.6E+00 -.160697E-05 4.25
 52 none -.6E+00 -.160697E-05 4.25 .1E-02 1
           -.3E+00 -.519615E+00 4.333333
 53 none -.3E+00 -.519615E+00 4.333333 .1E-02 1
           .300001E+00 -.519615E+00 4.416667
 54 none .300001E+00 -.519615E+00 4.416667 .1E-02 1
           .6E+00 .858591E-07 4.5
 55 none .6E+00 .858591E-07 4.5 .1E-02 1
           .299999E+00 .519616E+00 4.583333
 56 none .299999E+00 .519616E+00 4.583333 .1E-02 1
           -.300002E+00 .519614E+00 4.666667
 57 none -.300002E+00 .519614E+00 4.666667 .1E-02 1
           -.6E+00 -.853569E-06 4.75
 58 none -.6E+00 -.853569E-06 4.75 .1E-02 1
           -.299998E+00 -.519616E+00 4.833333
 59 none -.299998E+00 -.519616E+00 4.833333 .1E-02 1
           .300001E+00 -.519615E+00 4.916667
 60 none .300001E+00 -.519615E+00 4.916667 .1E-02 1
           .6E+00 .162128E-05 5.
 61 none .6E+00 .162128E-05 5. .1E-02 1
           .3E+00 .519615E+00 5.083333
 62 none .3E+00 .519615E+00 5.083333 .1E-02 1
           -.299999E+00 .519616E+00 5.166667
 63 none -.299999E+00 .519616E+00 5.166667 .1E-02 1
           -.6E+00 -.238899E-05 5.25
 64 none -.6E+00 -.238899E-05 5.25 .1E-02 1
           -.299999E+00 -.519616E+00 5.333333
 65 none -.299999E+00 -.519616E+00 5.333333 .1E-02 1
           .3E+00 -.519615E+00 5.416667
 66 none .3E+00 -.519615E+00 5.416667 .1E-02 1
           .6E+00 .31567E-05 5.5
 67 none .6E+00 .31567E-05 5.5 .1E-02 1
           .299998E+00 .519616E+00 5.583333
 68 none .299998E+00 .519616E+00 5.583333 .1E-02 1
           -.300001E+00 .519615E+00 5.666667
 69 none -.300001E+00 .519615E+00 5.666667 .1E-02 1
           -.6E+00 .653231E-06 5.75
 70 none -.6E+00 .653231E-06 5.75 .1E-02 1
           -.299998E+00 -.519617E+00 5.833333
 71 none -.299998E+00 -.519617E+00 5.833333 .1E-02 1
           .300001E+00 -.519615E+00 5.916667
 72 none .300001E+00 -.519615E+00 5.916667 .1E-02 1
           .6E+00 .114479E-06 6.
 73 none .6E+00 .114479E-06 6. .1E-02 1
           .299997E+00 .519617E+00 6.083334
 74 none .299997E+00 .519617E+00 6.083334 .1E-02 1
           -.300002E+00 .519614E+00 6.166667
 75 none -.300002E+00 .519614E+00 6.166667 .1E-02 1
           -.6E+00 -.882188E-06 6.25
 76 none -.6E+00 -.882188E-06 6.25 .1E-02 1
           -.3E+00 -.519615E+00 6.333333
 77 none -.3E+00 -.519615E+00 6.333333 .1E-02 1
           .300003E+00 -.519614E+00 6.416667
 78 none .300003E+00 -.519614E+00 6.416667 .1E-02 1
           .6E+00 .16499E-05 6.5
 79 none .6E+00 .16499E-05 6.5 .1E-02 1
           .3E+00 .519615E+00 6.583333
 80 none .3E+00 .519615E+00 6.583333 .1E-02 1
           -.299999E+00 .519616E+00 6.666667
 81 none -.299999E+00 .519616E+00 6.666667 .1E-02 1
           -.6E+00 -.241761E-05 6.75
 82 none -.6E+00 -.241761E-05 6.75 .1E-02 1
           -.299999E+00 -.519616E+00 6.833333
 83 none -.299999E+00 -.519616E+00 6.833333 .1E-02 1
           .3E+00 -.519615E+00 6.916667
 84 none .3E+00 -.519615E+00 6.916667 .1E-02 1
           .6E+00 .318532E-05 7.
 85 none .6E+00 .318532E-05 7. .1E-02 1
           .299998E+00 .519616E+00 7.083333
 86 none .299998E+00 .519616E+00 7.083333 .1E-02 1
           -.300001E+00 .519615E+00 7.166667
 87 none -.300001E+00 .519615E+00 7.166667 .1E-02 1
           -.6E+00 .624611E-06 7.25
 88 none -.6E+00 .624611E-06 7.25 .1E-02 1
           -.299998E+00 -.519617E+00 7.333333
 89 none -.299998E+00 -.519617E+00 7.333333 .1E-02 1
           .300001E+00 -.519615E+00 7.416667
 90 none .300001E+00 -.519615E+00 7.416667 .1E-02 1
           .6E+00 .143099E-06 7.5
 91 none .6E+00 .143099E-06 7.5 .1E-02 1
           .299997E+00 .519617E+00 7.583334
 92 none .299997E+00 .519617E+00 7.583334 .1E-02 1
           -.300002E+00 .519614E+00 7.666667
 93 none -.300002E+00 .519614E+00 7.666667 .1E-02 1
           -.6E+00 -.910808E-06 7.75
 94 none -.6E+00 -.910808E-06 7.75 .1E-02 1
           -.3E+00 -.519615E+00 7.833333
 95 none -.3E+00 -.519615E+00 7.833333 .1E-02 1
           .300003E+00 -.519614E+00 7.916667
 96 none .300003E+00 -.519614E+00 7.916667 .1E-02 1
           .6E+00 .167852E-05 8.
 97 none .6E+00 .167852E-05 8. .1E-02 1
           .3E+00 .519615E+00 8.083333
 98 none .3E+00 .519615E+00 8.083333 .1E-02 1
           -.300003E+00 .519613E+00 8.166667
 99 none -.300003E+00 .519613E+00 8.166667 .1E-02 1
           -.6E+00 -.244623E-05 8.25
 100 none -.6E+00 -.244623E-05 8.25 .1E-02 1
           -.299999E+00 -.519616E+00 8.333333
 101 none -.299999E+00 -.519616E+00 8.333333 .1E-02 1
           .3E+00 -.519615E+00 8.416667
 102 none .3E+00 -.519615E+00 8.416667 .1E-02 1
           .6E+00 .321394E-05 8.5
 103 none .6E+00 .321394E-05 8.5 .1E-02 1
           .299998E+00 .519616E+00 8.583334
 104 none .299998E+00 .519616E+00 8.583334 .1E-02 1
           -.300001E+00 .519615E+00 8.666667
 105 none -.300001E+00 .519615E+00 8.666667 .1E-02 1
           -.6E+00 -.398165E-05 8.750001
 106 none -.6E+00 -.398165E-05 8.750001 .1E-02 1
           -.299998E+00 -.519617E+00 8.833334
 107 none -.299998E+00 -.519617E+00 8.833334 .1E-02 1
           .300001E+00 -.519615E+00 8.916667
 108 none .300001E+00 -.519615E+00 8.916667 .1E-02 1
           .6E+00 .171718E-06 9.
 109 none .6E+00 .171718E-06 9. .1E-02 1
           .299997E+00 .519617E+00 9.083334
 110 none .299997E+00 .519617E+00 9.083334 .1E-02 1
           -.300002E+00 .519614E+00 9.166667
 111 none -.300002E+00 .519614E+00 9.166667 .1E-02 1
           -.6E+00 -.939428E-06 9.25
 112 none -.6E+00 -.939428E-06 9.25 .1E-02 1
           -.299996E+00 -.519617E+00 9.333334
 113 none -.299996E+00 -.519617E+00 9.333334 .1E-02 1
           .300003E+00 -.519614E+00 9.416667
 114 none .300003E+00 -.519614E+00 9.416667 .1E-02 1
           .6E+00 .170714E-05 9.5
 115 none .6E+00 .170714E-05 9.5 .1E-02 1
           .3E+00 .519615E+00 9.583333
 116 none .3E+00 .519615E+00 9.583333 .1E-02 1
           -.300003E+00 .519613E+00 9.666667
 117 none -.300003E+00 .519613E+00 9.666667 .1E-02 1
           -.6E+00 -.247485E-05 9.75
 118 none -.6E+00 -.247485E-05 9.75 .1E-02 1
           -.299999E+00 -.519616E+00 9.833333
 119 none -.299999E+00 -.519616E+00 9.833333 .1E-02 1
           .3E+00 -.519615E+00 9.916667
 120 none .3E+00 -.519615E+00 9.916667 .1E-02 1
           .6E+00 .324256E-05 10.
 121 none .6E+00 .324256E-05 10. .1E-02 1
           .299998E+00 .519616E+00 10.08333
 122 none .299998E+00 .519616E+00 10.08333 .1E-02 1
           -.300001E+00 .519615E+00 10.16667
 123 none -.300001E+00 .519615E+00 10.16667 .1E-02 1
           -.6E+00 .567371E-06 10.25
 124 none -.6E+00 .567371E-06 10.25 .1E-02 1
           -.300002E+00 -.519614E+00 10.33333
 125 none -.300002E+00 -.519614E+00 10.33333 .1E-02 1
           .300005E+00 -.519612E+00 10.41667
 126 none .300005E+00 -.519612E+00 10.41667 .1E-02 1
           .6E+00 .477797E-05 10.5
 127 none .6E+00 .477797E-05 10.5 .1E-02 1
           .299997E+00 .519617E+00 10.58333
 128 none .299997E+00 .519617E+00 10.58333 .1E-02 1
           -.300002E+00 .519614E+00 10.66667
 129 none -.300002E+00 .519614E+00 10.66667 .1E-02 1
           -.6E+00 -.968047E-06 10.75
 130 none -.6E+00 -.968047E-06 10.75 .1E-02 1
           -.3E+00 -.519615E+00 10.83333
 131 none -.3E+00 -.519615E+00 10.83333 .1E-02 1
           .299999E+00 -.519616E+00 10.91667
 132 none .299999E+00 -.519616E+00 10.91667 .1E-02 1
           .6E+00 .631339E-05 11.
 133 none .6E+00 .631339E-05 11. .1E-02 1
           .299996E+00 .519618E+00 11.08333
 134 none .299996E+00 .519618E+00 11.08333 .1E-02 1
           -.300003E+00 .519613E+00 11.16667
 135 none -.300003E+00 .519613E+00 11.16667 .1E-02 1
           -.6E+00 -.250347E-05 11.25
 136 none -.6E+00 -.250347E-05 11.25 .1E-02 1
           -.299999E+00 -.519616E+00 11.33333
 137 none -.299999E+00 -.519616E+00 11.33333 .1E-02 1
           .3E+00 -.519615E+00 11.41667
 138 none .3E+00 -.519615E+00 11.41667 .1E-02 1
           .6E+00 -.130646E-05 11.5
 139 none .6E+00 -.130646E-05 11.5 .1E-02 1
           .299994E+00 .519619E+00 11.58333
 140 none .299994E+00 .519619E+00 11.58333 .1E-02 1
           -.300005E+00 .519613E+00 11.66667
 141 none -.300005E+00 .519613E+00 11.66667 .1E-02 1
           -.6E+00 -.403888E-05 11.75
 142 none -.6E+00 -.403888E-05 11.75 .1E-02 1
           -.299998E+00 -.519617E+00 11.83333
 143 none -.299998E+00 -.519617E+00 11.83333 .1E-02 1
           .300001E+00 -.519615E+00 11.91667
 144 none .300001E+00 -.519615E+00 11.91667 .1E-02 1
           .6E+00 .228958E-06 12.
 145 none .6E+00 .228958E-06 12. .1E-02 1
           .300001E+00 .519615E+00 12.08333
 146 none .300001E+00 .519615E+00 12.08333 .1E-02 1
           -.300006E+00 .519612E+00 12.16667
 147 none -.300006E+00 .519612E+00 12.16667 .1E-02 1
           -.6E+00 -.55743E-05 12.25
 148 none -.6E+00 -.55743E-05 12.25 .1E-02 1
           -.299996E+00 -.519617E+00 12.33333
 149 none -.299996E+00 -.519617E+00 12.33333 .1E-02 1
           .300003E+00 -.519614E+00 12.41667
 150 none .300003E+00 -.519614E+00 12.41667 .1E-02 1
           .6E+00 .176438E-05 12.5
 151 none .6E+00 .176438E-05 12.5 .1E-02 1
           .3E+00 .519616E+00 12.58333
 152 none .3E+00 .519616E+00 12.58333 .1E-02 1
           -.299999E+00 .519616E+00 12.66667
 153 none -.299999E+00 .519616E+00 12.66667 .1E-02 1
           -.6E+00 -.710972E-05 12.75
 154 none -.6E+00 -.710972E-05 12.75 .1E-02 1
           -.299995E+00 -.519618E+00 12.83333
 155 none -.299995E+00 -.519618E+00 12.83333 .1E-02 1
           .300004E+00 -.519613E+00 12.91667
 156 none .300004E+00 -.519613E+00 12.91667 .1E-02 1
           .6E+00 .32998E-05 13.
 157 none .6E+00 .32998E-05 13. .1E-02 1
           .299998E+00 .519616E+00 13.08333
 158 none .299998E+00 .519616E+00 13.08333 .1E-02 1
           -.300001E+00 .519615E+00 13.16667
 159 none -.300001E+00 .519615E+00 13.16667 .1E-02 1
           -.6E+00 .510132E-06 13.25
 160 none -.6E+00 .510132E-06 13.25 .1E-02 1
           -.300002E+00 -.519614E+00 13.33333
 161 none -.300002E+00 -.519614E+00 13.33333 .1E-02 1
           .300005E+00 -.519612E+00 13.41667
 162 none .300005E+00 -.519612E+00 13.41667 .1E-02 1
           .6E+00 .483521E-05 13.5
 163 none .6E+00 .483521E-05 13.5 .1E-02 1
           .299997E+00 .519617E+00 13.58333
 164 none .299997E+00 .519617E+00 13.58333 .1E-02 1
           -.300002E+00 .519614E+00 13.66667
 165 none -.300002E+00 .519614E+00 13.66667 .1E-02 1
           -.6E+00 -.102529E-05 13.75
 166 none -.6E+00 -.102529E-05 13.75 .1E-02 1
           -.3E+00 -.519615E+00 13.83333
 167 none -.3E+00 -.519615E+00 13.83333 .1E-02 1
           .299999E+00 -.519616E+00 13.91667
 168 none .299999E+00 -.519616E+00 13.91667 .1E-02 1
           .6E+00 .637063E-05 14.
 169 none .6E+00 .637063E-05 14. .1E-02 1
           .299996E+00 .519618E+00 14.08333
 170 none .299996E+00 .519618E+00 14.08333 .1E-02 1
           -.300003E+00 .519613E+00 14.16667
 171 none -.300003E+00 .519613E+00 14.16667 .1E-02 1
           -.6E+00 -.256071E-05 14.25
 172 none -.6E+00 -.256071E-05 14.25 .1E-02 1
           -.299999E+00 -.519616E+00 14.33333
 173 none -.299999E+00 -.519616E+00 14.33333 .1E-02 1
           .3E+00 -.519615E+00 14.41667
 174 none .3E+00 -.519615E+00 14.41667 .1E-02 1
           .6E+00 -.124922E-05 14.5
 175 none .6E+00 -.124922E-05 14.5 .1E-02 1
           .299994E+00 .519619E+00 14.58333
 176 none .299994E+00 .519619E+00 14.58333 .1E-02 1
           -.300005E+00 .519613E+00 14.66667
 177 none -.300005E+00 .519613E+00 14.66667 .1E-02 1
           -.6E+00 -.409612E-05 14.75
 178 none -.6E+00 -.409612E-05 14.75 .1E-02 1
           -.299998E+00 -.519617E+00 14.83333
 179 none -.299998E+00 -.519617E+00 14.83333 .1E-02 1
           .300001E+00 -.519614E+00 14.91667
 180 none .300001E+00 -.519614E+00 14.91667 .1E-02 1
           .6E+00 .286197E-06 15.
Received on Fri Jun 26 1998 - 13:45:01 EDT

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