Welcome to WIFI Antennas

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

Admin

Simple Dipole Antenna

67 posts in this topic

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

2 people like this

Share this post


Link to post
Share on other sites
51 minutes ago, Dedewe said:

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

 

,,,yes...!!!

1 person likes this

Share this post


Link to post
Share on other sites

,,,which frequency.../?

1 person likes this

Share this post


Link to post
Share on other sites

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):

 

WhatsApp Image 2023-05-07 at 15.59.28(1).jpeg

WhatsApp Image 2023-04-27 at 22.50.06.jpeg

Edited by eco32

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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.

Untitledmmm.png

Share this post


Link to post
Share on other sites

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.

MicrosoftTeams-image (144).png

 

 

MicrosoftTeams-image (149).png

MicrosoftTeams-image (150).png

 

MicrosoftTeams-image (151).png

 

MicrosoftTeams-image (140).png

 

MicrosoftTeams-image (146).png

 

MicrosoftTeams-image (143).png

 

 

 

Share this post


Link to post
Share on other sites

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

screenshot_324.png

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

screenshot_328.png

Share this post


Link to post
Share on other sites

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

1296+feed+diameter.jpg

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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

WhatsApp Image 2023-05-23 at 22.01.15.jpeg

WhatsApp Image 2023-05-23 at 21.53.41.jpeg

Edited by eco32

Share this post


Link to post
Share on other sites

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

screenshot_384.png

 

screenshot_387.png

1 person likes this

Share this post


Link to post
Share on other sites
On 27.05.2023 at 9:33 AM, Admin said:

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

Clipboard02vswr.jpg

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 by eco32

Share this post


Link to post
Share on other sites

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.

slotted dipole.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now