Lutenna - The antenna made of Sugar

[Low Profile]

Probably because sugar crystals don't take up 100% of the volume.

 

[hexah]

The air in the spaces between the crystals are a dielectric, so you would be factoring in two dielectrics not just one (the sugar).

 

[Trust]

YouTube - GATR Setup Promo

same principle ??

 

[Low Profile]

It looks like the GATR is an inflatable dish, not the same (but an interesting concept nevertheless).

 

[pesarone]

hi
may be send to me pdf file plz
thx

 

[bostephen]

It´s not my invention, but i should be the first to build a multibeam antenna made of sugar

I´m preparing a PDF to explain the antenna and some possible versions of these type of antenna.

I am waiting for the PDF manual, coz the idea is jus t wonderful!

 

[bostephen]

The air in the spaces between the crystals are a dielectric, so you would be factoring in two dielectrics not just one (the sugar).

Sorry if my question is out of place, but since dielectric is mentioned here, I am tempted to ask if there is any material say glass that can work in an lnb in place of the dialectric plate to turn the H/V Horizontal/Vertical poarities into circular R/L Right/Left.

 

[Vorg]

A dialectric plate converts circular to linear, not linear to circular.

 

[Vorg]

I don't see how the gatr could work. Will have to look over their web site. The sphere works by bending the signals like a lens. Air would not bend the signal. So it must be in the materal use for the skin.

 

[casser]

I´ve abandoned this project a long time ago The main reason was i couldnt find other good dielectric materials to test.. i went to 2 styrofoam factories asking if they sell me a bag of polystyrene..but they refuse to sell/give.

Also my "original" idea is a bit wrong..a high performance lens sphere antenna need to have several layers of different dielectric materials.. see attach files to check a comparision from a sphere antenna with several layers. Althought a single layer dielectric sphere antenna works very good with small dimensions (100/200mm), bigger than that, it requires several layers, i cant give a theoretical explanation why this happen, but this what i think.

But..

A well known antenna manufacturer - Wavefrontier - has a spherical antenna of 750mm and 1000mm
-http://www.wavefrontier.com/wave/sphere.htm
brief explanation of the antenna
-http://www.wavefrontier.com/wave/technology.htm tech review

[warning]No live links please as per forum rules[/warning]

Since they only refer to polystyrene..so i believe it´s one layer only antenna

 

[Vorg]

We'll, hope this doesn't end up a double post. First try dissapeared. Foamed polystyrene looks like air to microwaves. was looking into using it to make a horn antenna and covering with foil. Having to put that project aside for now, but I got some more information on horn designs you might be interrested in Casser. But I'm not sure how much of it I should be posting public and I don't see a PM option here. It's not secret information,but was sent email, not posted on a forum.

 

[Topper]

You do not have PM facility until you have posted more and your post was moderated as you used a key word

Information is everyones right hence the purpose of a forum

 

[casser]

We'll, hope this doesn't end up a double post. First try dissapeared. Foamed polystyrene looks like air to microwaves. was looking into using it to make a horn antenna and covering with foil. Having to put that project aside for now, but I got some more information on horn designs you might be interrested in Casser. But I'm not sure how much of it I should be posting public and I don't see a PM option here. It's not secret information,but was sent email, not posted on a forum.

I tried once making a Horn antenna, but i had some problems sticking a round LNB into a rectangle antenna lol it was a 25dBi version, but didn't work. Conical horns are much simpler to build and give the extra 3dB, cant say if the Horn antenna also have that extra. The design that you have is about Horn ou Conical horn antennas?

if you want to build a antenna..i recommend Conical horns, this Lutenna or Lens antennas.

I never spoke about Lens antennas, because it´s very hard to build one that receive both pol. , but a lens antenna that work with only one pol (H or V) is very simple, a couple of styrofoam boards and aluminum cardboard does the trick very well. Also it´s multibeam. I´ll try to get a photo of a "prototype" i did with a lens antenna a couple of years agor that support for KU with both pol.

Foamed polystyrene is almost vacuum..i use a lot in antennas because of that, specially in conical horns made of cardboard i make a couple of "disks" of different diameter to stick inside the conical horn..the antenna becomes stronger and keep the conical form. Also it protects from the sun heat reaching the LNB..i´ll bet that a conical horn is a great solar oven...once i had a LNB so hot in a conical horn , that i almost burn my fingers.

 

[Vorg]

I emailed the addess in the pdf at http://www.redresa.org/LibroRESA/Documents/22a-UPNA_AG_2_A4.pdf and got a response.

The corrugations help if you want wide bands an low crosspolar levels. Let's say that for bands above 20% or two separate bands and for crosspolar levels below -35 dB you should use corrugations.
If that's not the case use a smooth profile.
Corrugated horns in any case are shorter than their same performance smooth profiles, around half the length (aperture size is the same, it is fixed by the neccesary gain).
Gaussian profiles lead to low sidelobe radiation patterns, as low as you want (limit usually -50 d.

No problem in making a horn or a corrugated horn in light material...

For radome the best material I know is GORE, please see the adjoining link:
http://www.gore.com/en_xx/products/fabrics/microwave/microwave_fabrics_radome_material.html

Regarding the horn antenna for C band; for the numbers you have given me, you need a horn antenna with around 43 to 45 dB gain (in the case of 8' dish diameter) or 40.5 to 42.5 dB gain (in the case of 6' dish diameter).

Both horn antenna requirements are impossible for just a horn, (well impossible not, but not practical). See the attached picture than ends in 30 dB gain horn antenna.
Your horn antenna would be around 4 metres long, perhaphs 3 metres with a very nice design but in such numbers. Regarding aperture size, the reduction comparing with a parabolic dish would be 10 to 15% in aperture diameter.

Holmdel horn antenna is just something similar to an offset reflector antenna configuration built in a block.

Corrugations can be made availlable to work for C and Ku bands, the main problem is the feeding of Ku band but there are several solutions, in any case corrugation depths would be around lambda/4 for C band but corrugation period must be much mor dense and around lambda/3 for Ku band, this means that for a C band corrugated horn of your requirements if 200 corrugations are needed if it must work at Ku band you need 600, and this would increase price and weight.

The chart he ref is in the pdf. And he would do a design, but he said a Holmdel style would take months. I did not ask about prices for a horn only because while much shorter then expected, it's still too big of a project. An improved Ku band design might be worth looking into though.

 

[yak_vi]

Hi, is possible use Styrofoam sphere? something like this:
_http://www.craft.com.au/images/DFB250.jpg

Thanks!