Re: NEC-LIST: Waveguide modeling

Mike,
I recently modelled an approximation to a conical feed for the Coffee Can
antenna. The file is attached below. It measured exactly (well, close
enough) as it simulated. Note that I used a very small length of wire as
the excitation source and then joined the 4 "elemental conical bits" from
the top end of it. That seemed to work best for me, even though the
thickness to length rule was violated.

Sincerely,
Trevor Marshall

CM COFFEE Can antenna for 802.11b, 2.4GHz
CM Coffee can: open cylindrical waveguide
CM Horn 135mm long, 100mm diameter
CM Design by Trevor Marshall
CM www.TrevorMarshall.com
CM from original concepts by W1GHZ, PA3AEF
CE **********************************************
SP 0 3 .050 -.007958 .135 .050 0.007958 .135
SC 0 3 .050 0.007958 .120 .050 -.007958 .120
SC 0 3 .050 0.007958 .105 .050 -.007958 .105
SC 0 3 .050 0.007958 .090 .050 -.007958 .090
SC 0 3 .050 0.007958 .075 .050 -.007958 .075
SC 0 3 .050 0.007958 .060 .050 -.007958 .060
SC 0 3 .050 0.007958 .045 .050 -.007958 .045
SC 0 3 .050 0.007958 .030 .050 -.007958 .030
SC 0 3 .050 0.007958 .015 .050 -.007958 .015
SC 0 3 .050 0.007958 .000 .050 -.007958 .000
SC 0 3 .02 0.003183 .000 .02 -.003183 .000
GM 0 4 .000 0.0 18.0
GM 0 0 .000 0.0 9.0
SP 0 0 .015 0.015 .000 90.0 .00000 .0009701
GX 0 110
GW 1 1 0.0354 0.0354 0.028 0.034 0.034 0.028 0.002
GW 2 4 .034 .034 .028 .016 .016 .026 .002
GW 3 4 .034 .034 .028 .016 .016 .028 .002
GW 4 4 .034 .034 .028 .016 .016 .030 .002
GW 5 4 .034 .034 .028 .018 .014 .028 .002
GW 6 4 .034 .034 .028 .014 .018 .028 .002
GM 0 0 0.0 0.0 45.0 0 0 -0.135
GM 0 0 0.0 90.0 0.0 0 0 0
GE
FR 0 7 0 0 2380.0 20.
EX 0 1 1 0 1.0 0
LD 5 0 0 0 3.72E+07
RP 0 73 73 1001 -90. 90. 5.0 5.0 10000.0
EN

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