• Public Gallery  • Help  
• Join Now!  • Log In  • Feature Tour
 holl_ands | Home > Bowties, Dipoles, Batwings & Rhombics > 
UHF Fractal Bowtie - No Reflector
UHF 4th Order Sierpinski Arrowhead (Fractal) Bowtie analyzed using 4nec2.

Three feedpoint geometries were analyzed:
1) End-Fed Anti-Symmetric (mirrored on Centerpoint vice Z-Axis) provided best Raw Gain and SWR,
but SWR was excessive on the lower frequencies, limiting the useful bandwidth.
The sharp dive in the (Forward) Gain curve corresponds to when the Azimuthal Pattern changes into a four-leaf clover,
with minimal Forward Gain...also note that Real Part of Impedance, R(ohm), nose dives down to only 25-ohms,
resulting in a very high SWR peak.  These severely limit the usable bandwidth.

2) End-Fed Symmetric (mirrored on Z-Axis) had poor Raw Gain and SWR identical to End-Fed Anti-Symetric.

3) Center-Fed Symmetric had poor Raw Gain as well as poor SWR.

These antennas would need to be Rescaled to match the desired operating band since they were very poor matches
for existing UHF Band.  SOURCE Wire length should them be varied to obtain best SWR.
Date(s): 21 Jan 2013. Album by holl_ands. 1 - 18 of 18 Total. 11024 Visits.
Start SlideshowTo order prints and photo-products: 1. Select photos. 2. Click Order. 3. Select products.Select images and click to download to your computer 
Enlarge photo 1
enlarge 66KB, 1024x1004
1
End-Fed Anti-Symmetric Fractal Bowtie
3D View


Enlarge photo 2
enlarge 335KB, 1024x1004
2
End-Fed Anti-Symmetric Fractal Bowtie
Front View
[1 big box = 1.25 inches]


Enlarge Microsoft Word Document 3
enlarge 52KB, 791x1024
DOC3
End-Fed Anti-Symmetric Fractal Bowtie
4nec2 File


Enlarge photo 4
enlarge 192KB, 1024x734
4
End-Fed Anti-Symmetric Fractal Bowtie
Raw Gain 300-1000 MHz


Enlarge photo 5
enlarge 214KB, 1024x734
5
End-Fed Anti-Symmetric Fractal Bowtie
SWR (300-ohms) 300-1000 MHz


Enlarge photo 6
enlarge 296KB, 1024x734
6
End-Fed Anti-Symmetric Fractal Bowtie
Impedance 300-1000 MHz


Enlarge photo 7
enlarge 61KB, 1024x1004
7
End-Fed Symmetric Fractal Bowtie
3D View


Enlarge photo 8
enlarge 338KB, 1024x1004
8
End-Fed Symmetric Fractal Bowtie
Front View
[1 big box = 1.25 inches]


Enlarge Microsoft Word Document 9
enlarge 52KB, 791x1024
DOC9
End-Fed Symmetric Fractal Bowtie
4nec2 File


Enlarge photo 10
enlarge 197KB, 1024x734
10
End-Fed Symmetric Fractal Bowtie
Raw Gain 300-1000 MHz


Enlarge photo 11
enlarge 212KB, 1024x734
11
End-Fed Symmetric Fractal Bowtie
SWR (300-ohms) 300-1000 MHz


Enlarge photo 12
enlarge 294KB, 1024x734
12
End-Fed Symmetric Fractal Bowtie
Impedance 300-1000 MHz


Enlarge photo 13
enlarge 64KB, 1024x1004
13
Center-Fed Symmetric Fractal Bowtie
3D View


Enlarge photo 14
enlarge 335KB, 1024x1004
14
Center-Fed Symmetric Fractal Bowtie
Front View
[1 big box = 1.25 inches]


Enlarge Microsoft Word Document 15
enlarge 45KB, 791x1024
DOC15
Center-Fed Symmetric Fractal Bowtie
4nec2 File


Enlarge photo 16
enlarge 203KB, 1024x734
16
Center-Fed Symmetric Fractal Bowtie
Raw Gain 300-1000 MHz


Enlarge photo 17
enlarge 215KB, 1024x734
17
Center-Fed Symmetric Fractal Bowtie
SWR (300-ohms) 300-1000 MHz


Enlarge photo 18
enlarge 301KB, 1024x734
18
Center-Fed Symmetric Fractal Bowtie
Impedance 300-1000 MHz


 Select All.  
  Sign the Guestbook. There are no entries.