Simple Dipole Antenna

[Admin 2644]

 I don't really think so, it has to be checked...!!!

[alhaba.production 7]

13 hours ago, Admin said:

 I don't really think so, it has to be checked...!!!

Thanks sir

[Dedewe 1]

it is for 50 ohm for 75 ohms is there a size change mr

[Admin 2644]

51 minutes ago, Dedewe said:

it is for 50 ohm for 75 ohms is there a size change mr...???

 

,,,yes...!!!

[Dedewe 1]

what range according to mr

[Admin 2644]

,,,which frequency.../?

[Dedewe 1]

this is the frequency in my country mr

[Dedewe 1]

B3

[eco32 44]

i like to try do  such feed for a 1296MHZ, but I'm not sure about the dimensions, colleagues please tell me what would be the dimensions for a model with two reflectors. This one is too short, I modeled in matlab, resonance at 1500MHz (split coaxial balun):

 

Edited May 9, 2023 by eco32

[Admin 2644]

 

[eco32 44]

Thank You!, please give me few days to build this, i will show You the result

[eco32 44]

I cannot find a commercial implementation of such an "feed"  also no publication with  "rear dipole feed with two reflectors". May the name is very specific, google does not return anything meaningful.

[eco32 44]

It is based on Pacyfic Grid 917x720 and 15cm deep 5.6GHz grid antenna symulation + Yagi Uda in revers - directors works likea rediators (This is not a good representation, Matlab has big limitations)

1296MHZ => 17.3dBi

oryginal grid antenna https://www.cyberbajt.pl/produkt/350/pacific-grid-56-ghz28-dbi.html

 

[eco32 44]

something about thos antenna from 1968

The Radio Amateur's V.H.F. Manual  - A Manual of Amateur Radio Communication on the Frequencies Above 50 Megacycles  1968

https://dokumen.pub/the-radio-amateurs-vhf-manual-a-manual-of-amateur-radio-communication-on-the-frequencies-above-50-megacycles-11th-ed.html

 

(I will try do my own for a 1296MHz)

From the description, it seems that it is not a "simple dipole" but a slot antenna.

 

 

 

 

 

 

 

 

 

[Admin 2644]

,,,yes, it fits...!!!!

,,,and in the focus of an offset disc...

[eco32 44]

Diameters for a 1296MHz

On 15.05.2023 at 0:34 PM, Admin said:

,,,yes, it fits...!!!!

 

     Hi, it looks very good!

Could You try diameters for a 1296MHz?

lambda      127.118644      lamda      231.481481

                          

13cm(inch)      13cm(inch)      13cm(mm)      alfa      23cm

2+1/2      2.5      63.5      0.49953333      115.632716

11/64      0.171875      4.365625      0.03434292      7.94974923

1+1/4      1.25      31.75      0.24976667      57.816358

1+27/64      1.421875      36.115625      0.28410958      65.7661073

1+3/32      1.09375      27.78125      0.21854583      50.5893133

2+7/16      2.4375      61.9125      0.487045      112.741898

 3/16      0.1875      4.7625      0.037465      8.6724537

 15/16      0.9375      23.8125      0.187325      43.3622685

2+7/16      02-Jan      61.9125      0.487045      112.741898

[Admin 2644]

,,,okay, I'll try to satisfy your desire...!!!

[eco32 44]

Thats grid with dipole rear feed with splited coaxial balun, basic version (1) with one reflector on the feed

Edited May 24, 2023 by eco32

[eco32 44]

This type of antenna is patented : US5191350 LOW WIND LOAD PARABOLIC ANTENNA, for more details check pdf file.

 

US5191350 LOW WIND LOAD PARABOLIC ANTENNA.pdf

[Admin 2644]

,,,old trash...!!!

[eco32 44]

On 24.05.2023 at 8:14 PM, Admin said:

,,,old trash...!!!

MIT Radiation Lab Series V12 Microwave Antenna Theory and Design  1949 

chapter 8 Microwave dipole antennas and feeds

https://www.scribd.com/document/35903457...and-Design#

[Admin 2644]

,,,the dimensions of this are not clear...the dimensions are in inches and the wavelength in centimeters...???

,,,a very old book, it can help someone...

 

12 - Microwave Antenna Theory and Design.pdf

[Admin 2644]

,,,yes, it seems that this dipole with circular reflector is good....!!!

 

[eco32 44]

On 27.05.2023 at 9:33 AM, Admin said:

,,,yes, it seems that this dipole with circular reflector is good....!!!

WOW! The antenna is very broadband! It Covers the entire 23cm band, this type of design is also suitable for LTE/5G

I have read that for grid parabolic antennas the reflector can be narrower, it does not have to be a circle, it can be a rectangle with rounded corners

With  my firs 13dBi design, I made the QSO with 250mW over a distance of 8km using the reflection of a tall office building. (I have different grids: 600mmx400mm 13dBi, 700mm x 900mm 17dBi)

Edited May 31, 2023 by eco32

[eco32 44]

Design with slot or with  coaxial splited balun - the reflector disc is smaller than the previous design, I guess that's the reason for the lower gain.