21dbi (or more) 4 by 4 Patch Array

[clanon 246]

Been beating around the bush for years to find a Good 4x4 patch array...

Higher than 21 dbi , good impedance through the whole band,low enough vswr, under -20dbi side lobes...

the original design is for 12,5 ghz and almost none side-lobes Power distribution Ratio 1:5:5:1

Changed it to WiFi ,  distribution ratio 1:1:1:1 (Original design Eliminated Sidelobes at the COST of 1,5-2dbi of gain)

I'm happy (some testing still needed )

REAL dielectric constant of Polystyrene foam is a guess (1.02-1.05)

 

 

[clanon 246]

Brass 0.2 mm (patches and Central Feed) , Copper Tape (0.0254 mm) feed branches

[clanon 246]

Efficiency of Polystyrene foam ...is unbeatable...

More losses on metal than dielectric...

 

[clanon 246]

Feed network is at 2 mm from Aluminum Reflector , Patches are at 4 mm from Reflector...

There's a "tendency" these days to believe that Laser cutting-3D printing  and AESTHETICS are a key factor...FALLACY

Energy doesn't care about aesthetics it only Flows were possible , mm or single degrees error don' make much of a difference

BUT dielectric Constant MUST BE KNOWN...to get to the ballpark.

Edited November 3, 2023 by clanon

[Admin 2545]

,,, some dimensions, is it possible...??

[clanon 246]

i have A model (my ssd failed with the original but i had the dimensions on paper) could put the dxf of the feed and patches are ALL the same

42 by 44 cm reflector

Model should be customized to Dielectric used in each case

 

branches.dxf

Centerfeedline.dxf

patches.dxf

Edited November 3, 2023 by clanon

[clanon 246]

Styrofoam (lowest density better)

cut with resistance wire (nichrome) at 2 mm flat

 

[clanon 246]

 

 

[Admin 2545]

,,,but if galvanized sheet and wire supply lines are used....???

[clanon 246]

it would be interesting...could be Laser cut or stamped...Wires have more REACTIVITY (Imaginary Z) Inductive reactance...impedance curve is always smaller...2mm copper ...maybe...

Copper tape is easy to cut with cutter under print drawing taped on top...perfect

you get more losses in the metal distances should stay the same and sizes...

to keep a good Impedance and low 2 mm or LESS from reflector the Feed network

Patches 4 mm or more from reflector (there is a step of 2 mm)

Edited November 4, 2023 by clanon

[Admin 2545]

[clanon 246]

yup...5.84 cm by 5.4 cm...(these are HIGHLY related to the Dielectric Factor , change from 0,4 to 0,5 would change several millimeters these dimensions)

[clanon 246]

On 3/11/2023 at 3:40 PM, Admin said:

,,,but if galvanized sheet and wire supply lines are used....???

I would give it a go ...BUT with circular patches...we'll see...(you had one like that YEARS ago... mimo...remember...

[tomasbj 5]

On 3/11/2023 at 2:06 PM, clanon said:

Styrofoam (lowest density better)

cut with resistance wire (nichrome) at 2 mm flat

 

Hi Guys, What is the loss tangent of this material?

[clanon 246]

one of the LOWEST in the world 0.0003  at 3000 mhz  , only one better Polypropylene...at higher frequencies...5.8 ghz ideal...

 

Edited November 21, 2023 by clanon

[tomasbj 5]

Very interesting, Thanks for sharing! I was working with Rohacell

Since it has very low relative permittivity and low tangent loss too.

[clanon 246]

Water absorption should be adressed in PES foam...Changes ALL.

PVC pipe has THIS weirdness...

Edited November 29, 2023 by clanon

[clanon 246]

VNA measurements