2M Antenna

[Admin 2578]

Good yield an antenna that can be mounted on an offset parabola...

 

 

[Admin 2578]

Another construction to enlarge frequency band in 3G...

 

 

[Admin 2578]

,,,an older achievement of the TUL user,for which the antenna was improved....!!!

[Admin 2578]

,,,and now let's see how this antenna behaves...

[Admin 2578]

,,,for which this antenna was simulated ... !!!!

 

[Admin 2578]

,,,for which type of antenna I tried an optimization to increase the bandwidth ... ???

[bejonet 58]

how many beamwidth degrees for this antenna

Edited February 8, 2019 by bejonet

[Admin 2578]

[Carlos 3]

looks easy to make

[Samsterino2.4 2]

Hello Admin , I've been here awhile following closely, i appreciate you more than you know! A true scientist! Thank you. So I wanted the first time I come forth to show you all the things that you helped me create that you don't know exists! They do. I constantly improve so they all need my revised touch so not yet. I want to go the next level and i need some guidance. I want to do a parabolic build with the best damn feed possible. I've seen the power of the parabolic dish just fooling around. I know how to calculate the focal point for a cassagrain centered but i don't know how to place an offset feed...and i haven't found a feed that vibes with me. So im wondering two things if you can point me in the right direction, i have options for the dish. I have an  elliptical shaped dish and a circular. From what I've learned i think center for the circle and offset for the ellipse. I need to know how to calculate for the offset and i'm asking for some secret sauce. What's the best director for these dishes. I like this patch but not if you know of a better  when does the amount of directors start to reduce Range when used with a parabolic dish. Measurements if you want them!! Thanks teacher you've already gave me access to so much! 

[Admin 2578]

,,,hi buddy...!!!

,,,as far as I understand , you want to use a Cassegrain Offset with this double patch antenna...!!!

,,,something like that ... !!!

[Hamza 43]

jomy how these patchs are supported ? or the construction not achieved yet ???

[Admin 2578]

,,, in the air with dielectric spacer supports in the center of the patch...!!!

[Hamza 43]

merci  mister jomy   i will try it for  parabolic offset

[Admin 2578]

However, this latest optimization has a wider frequency band...

,,, and a better gain in directivity....

[Hamza 43]

Dimensions please .

[Admin 2578]

On 11/19/2020 at 8:18 PM, Hamza said:

Dimensions please .

 

 

[Samsterino2.4 2]

The site was down for awhile?? I'm glad its back and everything is ok. I can host on my server anytime if you need as failover just let me know!

So to business. This is design i great. But I still don't know the distance from parabola and the offset distance? Still cannot find a formula for offset. Focal point of parabola f = D2 / 16d I know....but offset...how?

[Samsterino2.4 2]

This is hard to understand for me,,,im sorry i blame the eyes and old age. is the bottom strip 92mm end to end? and the angle of cut?? and then the patches,,,,, are they attached to bottom strip? If someone has a few pictures of the bottom angles so i can see how it looks! Thanks if you do!!

 

 

[Admin 2578]

10 hours ago, Samsterino2.4 said:

The site was down for awhile?? I'm glad its back and everything is ok. I can host on my server anytime if you need as failover just let me know!

So to business. This is design i great. But I still don't know the distance from parabola and the offset distance? Still cannot find a formula for offset. Focal point of parabola f = D2 / 16d I know....but offset...how?

Offset satellite antenna is a section of a paraboloidal reflector with oval form. The antenna surface is not round anymore, but oval (ellipse) and symmetric. The focal point is not mounted in the middle of the dish, but to the side of the dish (offset). Thus, the advantage of this technology, is that the antenna surface is not being shadowed by the feed anymore (from the satellite's point of view).
Another advantage is the less likelihood that snow will build up on the dish. The offset satellite antenna does not "look" straight up to the satellite as a Prime Focus antenna does, but it's inclined about 25° downward (almost upright position). Nevertheless, an offset dish appears for the satellite to be circular having the horizontal diameter.

 

 

[clanon 258]

On 11/19/2020 at 4:16 AM, Samsterino2.4 said:

 I want to do a parabolic build with the best damn feed possible.

you might wanna look for BEST EFFICIENCY (low SPILLOVER , perfect ILLUMINATION)

Blockage is important on small front feed dishes (the shade of the feed over the dish)

the gain is of NO IMPORTANCE (on the feed) reflector is CLOSE BY...

The SHAPE of the MAIN LOBE ( only one if possible)

f-D ratio is your KEY NUMBER (0.2 to 0.5)

lower f-D ratio = focus CLOSE to the rim- bigger f_D ratio focus FAR AWAY

from f-D ratio yo'll know WHAT lobe of directivity would give you best ILLUMINATION (efficiency)

THESE are the values for my dish 0.26 f-D ratio (meaning that the feed must provide 180 degrees of lobe at -6db)

feed for 0,25 0.3 f_D ratios

 

Edited December 6, 2020 by clanon

[clanon 258]

all the info on parabolic dishes

if you could get 70% efficiency you're GOLDEN

 

 

 

Edited December 6, 2020 by clanon

[Admin 2578]

,,, I think a new post should be opened with this topic (offset dish antenna)...!!!

,,, I will open a new post and you will complete it ,,, the above mentioned will be deleted...!!!

[vige3 0]

Hi,

Its very tempting proposal. Small antenna but high gain.

Just two remarks...

- Can a build this with N type connector?

- Can i use this antenna as main, not as feeder for parabola?

[Admin 2578]

15 minutes ago, vige3 said:

Hi,

Its very tempting proposal. Small antenna but high gain.

Just two remarks...

- Can a build this with N type connector?

- Can i use this antenna as main, not as feeder for parabola?

,,, yes, you can use the desired connector..!!!

Yes you can...!!!