MY LOW NOISE AND WIDEBAND 4x9EL EME ANTENNA SYSTEM
my goal for this work:
after the good success with the 4x8EL antenna system i decided to give the 8EL system a little upgrade
without big changing of the main parameteres.
So i started my work again....to find
a good solution for an upgrade ...
the result was my new 9EL Design with 4.3m BOOM 11.5dBd Gain
simulation results of the single 9EL antenna:
| TYPE |
L |
GAIN |
FWD |
SIDELOBE |
BACK |
Tlos |
Ta |
G/T |
frequency |
remarks |
| DG0OPK_9EL |
2.06 |
11.46 |
182.98 |
49.80 |
2.07 |
4.81 |
239.68 |
-10.19 |
144.0 MHz |
|
| DG0OPK_9EL |
2.06 |
11.53 |
183.23 |
49.35 |
1.54 |
5.06 |
239.29 |
-10.11 |
144.5 MHz |
|
| DG0OPK_9EL |
2.06 |
11.57 |
182.79 |
50.41 |
2.02 |
5.12 |
240.30 |
-10.09 |
145.0 MHz |
|
| DG0OPK_9EL |
2.06 |
11.55 |
173.08 |
54.96 |
4.21 |
4.99 |
245.82 |
-10.20 |
145.8 MHz |
L = Length in Wavelengths
FWD = Forward Lobe Noise Temperature
SIDELOBE = Sidelobe Noise temperature
BACK = Antenna Noise made from backside lobe
Gain = Gain in dBd of antenna (without losses)
Tlos = The internal resistance of the antenna in degrees Kelvin (high losses means critical design)
Ta = The total temperature of the antenna in degrees Kelvin. This
includes all the side lobes, rear lobes and internal resistance of the antenna.
G/T = Figure of merit used to determine the receive capability of the antenna
(Ga + 2.15) - (10*log Ta). The more positive figure the better.
simulated horizontal and vertical pattern
simulated SWR over frequency
simulated impedance over frequency
overall SWR measurement of the complete system
(on the antenna connector in my shack)
| Element |
Length |
Distance |
Diameter |
| reflector |
1024 |
0 |
5 |
| driven |
988 |
344 |
8 |
| director 1 |
962 |
577 |
5 |
| director 2 |
935 |
1071 |
5 |
| director 3 |
918 |
1703 |
5 |
| director 4 |
904 |
2411 |
5 |
| director 5 |
876 |
3050 |
5 |
| director 6 |
856 |
3666 |
5 |
| director 7 |
830 |
4300 |
5 |
stacking parameters for an array of 2 x 2 for low sidelobes and moderate gain
(that could be my use in the city or in my home location)
calculatet noise temperature parameters
for the complete system
(Tsky=200K,Tearth=1000K)
stacking
distance H = 2.5m , V = 2.3mGain @ 144 MHz = 16.75dBd (18.9dBi)
forward noise temperature of the system @
144MHz:
192.29K
sidelobe noise temperature @ 144 MHZ:
22.52K
backside lobe noise temperature @ 144
MHZ: 0.99K
loss temperature @ 144 MHZ:
4.7K
overall antenna noise temperature @ 144 MHz: ca. 220K
G/T value calculations (using Tant by YT1NT, and tnx for help from Boban YU7XL)
| frequency | gain |
noise temperature (without losses) |
G/T value |
| 144.0 MHz |
18.90dBi |
217.1 K |
-4.47dB |
| 144.5 MHz |
18.98dBi |
215.3 K |
-4.35dB |
| 145.0 MHz |
19.03dBi |
215.4 K |
-4.30dB |
| 145.8 MHz |
19.06dBi |
218.1 K |
-4.33dB |
stacking
parameters for an array of 2 over 2 for maximal gain
stacking distance H = 2.95m , V = 2.55m
Gain @ 144 MHz = 17.5dBd (19.7dBi)
forward noise temperature of the system @
144MHz:
187.52K
sidelobe noise temperature @ 144 MHz:
36.86K
loss temperature @ 144 MHz: 4.78K
overall antenna noise temperature @ 144 MHz: ca. 230K
G/T value regarding to VE7BQH chart : -3.96dB
Special Note:
This design is the work on many simulations and measurements over some month.
The mechanical work costs a lot of money and time of my friend Pit DM2CKK.
Special thanks also to Karsten DM2CT and Jens DD5JE.
Distribution and publishing of these data and information is permited ONLY
for radioamateur purposes and construction.
Use of these information and data for any commercial purposes is strictly prohibited
without the written authorization of the author.
if you are interested in some special parts or complete antennas write me an email ....
last change: 4.august 2007
(DG0OPK)