Re: NEC-LIST: Modeling of Simple Dipole

Hi,

> I calculated gain of Dipole antenna by two programs. One is modeling
> an antenna by only one wire,but another is by three wires,as below.
> As a result,I obtained different answers. The first's was 2.12dBi,the
> other's was 4.24dBi. In addition,Impedances were 72.533+j3.471,
> 44.458+j1.389.

for some reason, NEC doesn't like sudden changes in segment
lengths along a wire. In your second model, the central segment
is only about one tenth the length of the other segments.

Incrasing its length by a factor of ten changes your second
model to:

CM Simple dipole antenna in Free Space
CM 3-wires *** modified: replaced .5 by 5. ***
CE
GW 1,4, 0,5.,0, 0,48,0, 0.1
GW 2,4, 0,-5.,0, 0,-48,0, 0.1
GW 3,1, 0,-5.,0, 0,5.,0, 0.1
GS 0 0 .01
GE 0
EX 0 3 1 00 1 0
FR 0 1 0 0 150 1
RP 0 181 1 1000 -90 90 1 1
FR 0 1 0 0 150 1
RP 0 181 1 1000 -90 0 1 1
EN

This gives 2.14 dBi of gain and an impedance of 72.1 + 3.4j Ohms
when run through NEC2D.

Cheers,
Joachim
Received on Mon Oct 20 1997 - 09:48:59 EDT