RE: NEC-LIST: Bow_Tie antenna

stanley:

i am not an expert on using nec2 for antenna simulation, but i have worked a
little on the bow-tie problem you referred to. it is my impression (from the
nec-2 manual) that you cannot use surface patches for this problem. i
simulated the antenna using discrete wires in a mesh. below is my code for
an antenna with a nominal range of 100-400 MHz. the frequency response is
calculated from 10 to 600 MHz in 10 MHz steps, although i'm not sure how
valid the response is at the upper frequency range past 500 MHz or so.
extracting the frequency response from the nec2 output listing is tedious,
so i created a macro in a word processor to automate the process. i'm using
symmetry to reduce the number of calculations - the GW statements below
define only 1/2 of one antenna leaf. i'm also more interested in the
frequency response rather than the radiation pattern, so i only calculate
the pattern at a couple of aspect angles. my particular application is
ground penetrating radar (i use a loaded bow-tie to lower the Q of the
antenna). i can email you the specific data i obtained for this simulation
if you wish. good luck with your project, and please let me know whether my
code is useful or not.

neil chamberlain
electrical and computer engineering
south dakota school of mines and technology
nchamber_at_silver.sdsmt.edu

CM Nominal 100-400 MHz Bowtie Antenna in Free Space
CM invoking symmetry
CM 24 wire / leaf (12 radial & 12 circumferential wires)
CM Neil Chamberlain 1996
                                                                              

CE
GW 1 6 -0.07620 0.15452 0.00000 0.00000 0.00000 0.00000 0.00100
GW 2 5 -0.15240 0.30904 0.00000 -0.07620 0.15452 0.00000 0.00100
GW 3 5 -0.22860 0.46355 0.00000 -0.15240 0.30904 0.00000 0.00100
GW 4 6 -0.02540 0.15452 0.00000 0.00000 0.00000 0.00000 0.00100
GW 5 5 -0.05080 0.30904 0.00000 -0.02540 0.15452 0.00000 0.00100
GW 6 5 -0.07620 0.46355 0.00000 -0.05080 0.30904 0.00000 0.00100
GW 7 6 -0.22860 0.46355 0.00000 -0.07620 0.46355 0.00000 0.00100
GW 8 3 -0.07620 0.46355 0.00000 0.00000 0.46355 0.00000 0.00100
GW 9 4 -0.15240 0.30904 0.00000 -0.05080 0.30904 0.00000 0.00100
GW 10 2 -0.05080 0.30904 0.00000 0.00000 0.30904 0.00000 0.00100
GW 11 2 -0.07620 0.15452 0.00000 -0.02540 0.15452 0.00000 0.00100
GW 12 1 -0.02540 0.15452 0.00000 0.00000 0.15452 0.00000 0.00100
GX 12 110
GS 0 0 1
GE 0
EX 0 1 6 0 -1 0
EX 0 4 6 0 -1 0
EX 0 25 6 0 -1 0
EX 0 28 6 0 -1 0
EX 0 13 6 0 1 0
EX 0 16 6 0 1 0
EX 0 37 6 0 1 0
EX 0 40 6 0 1 0
FR 0 61 0 0 10 10
PT -1
RP 0 1 1 1000 0 0
EN

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From: davem
To: nec-list
Subject: Bow_Tie antenna
Date: Thursday, October 17, 1996 11:30AM

Good day,

August last year Afrim posted to nec-list group requiring information
about using NEC2 to simulate a bow-tie antenna. Can anyone please tell
me how to do that? Can I use wires of various length to generate the
shape of bow-tie each spacing about 0.05-0.1 of a wavelength? Or can I
use the surface patch to generate the two triangular patches
(bow-tie), then fill in the middle with wires? I am open to
suggestion. Any information would be very much appreciated.

Thanks,
Stanley
Received on Fri Oct 18 1996 - 08:31:30 EDT