Looking for 2.4ghz yagi design for DIY pcb etching

[Akinetopsia 0]

Hello,

i'm looking for a PCB yagi design that i could etch myself, preferably single-sided.

i found this post, but it's missing two dimensions (the red arrows)

Worse comes to worst i could probably replicate the antenna from my cheap chinese adapter - which is apparently a good design but crippled by the cheap radio - however that would require milling the parts with my horrendously noisy tabletop cnc. Etching seems preferable.

 

 

I intend to replace the cheap adapter with an Alfa and would like to etch a pair of directional antennas so that i can remote control a telescope sitting out in the field about 600 feet away from the house:

 

 

 

 

[Admin 2545]

,,,the two dimensions upper the red arrows(6:11)...

,,,on this site you will find enough antennas to interest you...!!!

[Akinetopsia 0]

16 minutes ago, Admin said:

,,,the two dimensions upper the red arrows(6:11)...

 

Ah nice, thanks a bunch!

Quick question, looking at the original post, specifically this very small image:



this seems like a "shorted" design where the driven element is tied to the ground plane via the shielding, am i reading that right ?

I can work my way with regular electronics but i am a total noob regarding RF stuff and i must admit that shorting the active element to ground feels a bit wrong
While doing research I watched a few videos from andrew mcneil, although i might be completely wrong iirc he mentioned something about shorted systems impacting transmission power.

So if i understand correctly, the ground plane is connected in the following way ?

 

Again, thanks a lot!

Edited November 19, 2022 by Akinetopsia

[Akinetopsia 0]

Scratch that, overall dimension is about 23cm (9in) which is both larger than my UV transfer area and my copper clad laminate.

I really don't know enough to attempt to alter / design my own so I guess i'll have to replicate the antenna from the cheap wifi adapter after all, unless someone has another design to share.

It just so happens that Andrew McNeil i mentioned earlier did in fact test that same adapter and was surprised by that antenna:

He also shared the template for anyone interested:

https://drive.google.com/file/d/1zH7BWUTtpRWf4_ULaa7pfrSGhuKIpx-O/view

 

 

[Dr. Pepper 58]

If you only want a connection 600m away on a field you could also simply use 2 Cantennas. I made a fast and stable connection with 2 Cantennas over 7 Km without any problem, but there was nothing in between otherwise such ranges are near to not possible. 

[Akinetopsia 0]

I liked the idea of what amounts to basically 2D antennas, as lugging 80 pounds of kit from the city to the burbs kind of a pita plus my kit bag is already pretty full but i may look into cantennas .. 7km is damn impressive!

i do have some trees in the way, a patch about about 100ft / 30m long or so, though

 

I may also give this design a try as it's smaller, but it's two sided

https://drive.google.com/file/d/1ABpQVXIWWiwi8oFFaEO1FPkJDI2PzTeZ/view

Edited November 19, 2022 by Akinetopsia

[Admin 2545]

,,,for LINWLAN2,4GHz Antenna look at here : https://drive.google.com/file/d/1YUtCtA57I8AyKA4WGt4QRwAIShzAoUJn/view

,,,or maybe you want to do one of these...

[Admin 2545]

,,, it's still possible...

[Akinetopsia 0]

On 2022-11-20 at 3:11 AM, Admin said:

,,,for LINWLAN2,4GHz Antenna look at here : https://drive.google.com/file/d/1YUtCtA57I8AyKA4WGt4QRwAIShzAoUJn/view

,,,or maybe you want to do one of these...

 

Ah, i see it was already a known type !

Thanks! I must admit that last one looks like a death ray gun from some 50's b-movie a bit ;D

i went with this design:

It looks like crap, uneven etching and my laminator decided to strip a gear and jam with the board halfway in, hence the terrible soldermask. I'll most likely make another.

In fact I am probably going to try both types - just not the super long one.. as i mentioned the smaller the profile the better.

 

 

Edited November 21, 2022 by Akinetopsia

[Admin 2545]

,,,what do you use the telescope for...?...for drones...???

[Akinetopsia 0]

11 hours ago, Admin said:

,,,what do you use the telescope for...?...for drones...???

 

well i guess the scope is kind of a drone itself ?

I use it for astrophotography, stuff like this:

 

I picked the hobby during the pandemic but i haven't got the chance to use it many times yet. Basically once set up it is fully remote-controllable and automated.

Imaging deep sky objects requires a lot of integration time (exposure time, if you will), often tens of hours. While it's fun during the summer in Canada our winters are quite cold, but it's also when the nights are the longest and the sky clearer so the goal is to be able to leave it outside while sitting comfortably at the computer inside, a little bit like one would do with a large observatory -- except with a drink

I built the control system using a raspberry pi 4 running Astroberry, a Linux environment with a suite of astronomy-related software along with some custom code for the imaging. It basically has a complete desktop i can remote into.

Here's a better look at the kit:

 

[Admin 2545]

,,,oooh, it looks good to me, a very interesting hobby...!!!

... and then why do you still need the wifi antenna...???

[Akinetopsia 0]

> ... and then why do you still need the wifi antenna...???

In order to have an unobstructed view of the sky, i have to set it up in the middle of a field about ~600ft / 200m away (it's battery operated) and the signal i get from my current wifi adapter is too weak, slow and disconnects.

So basically i ordered an Alfa adapter and a small tp-link travel router that i'll modify each with a directional antenna: one on the scope and one from the house pointing at each other and *hopefully* get a good connection

 

I have to carry all that stuff from the city where i live to the family house where i can observe, hence why i want to DIY something portable

[Admin 2545]

,,,the Yagi antenna on the PCB does not have special qualities, why don't you try a Bester antenna...???!!!

[Akinetopsia 0]

hmm, i was under the assumption that a directional antenna focused the available transmission power from the radio where you want it, instead of of spreading it 180° around like with an omni

Am i mistaken in my understanding that two directional antennas pointed at each other would improve reception ?

 

As it is right now, i have the LINWLAN style antenna but with a bad/cheap wifi radio, and at the house i have a basic wifi repeater in the wiindow.

I want to change this to: better radio in the field, either with LINWLAN antenna or a yagi, and a yagi inside the house

 

What would you suggest ? I guess Cantennas could work but they take up luggage space

Edited November 23, 2022 by Akinetopsia

[Admin 2545]

,,,two of these antennas...

[Admin 2545]

,,,why don't you try the Batwing antenna...???

[Akinetopsia 0]

On 2022-11-23 at 6:53 AM, Akinetopsia said:

hmm, i was under the assumption that a directional antenna focused the available transmission power from the radio where you want it, instead of of spreading it 180° around like with an omni

i meant 360 there, didn't had my coffee

 

5 hours ago, Admin said:

,,,why don't you try the Batwing antenna...???

That's.. omni, no ? I need directional

 

Anyway turns out I ordered the wrong stuff. Both the Alfa AWUS036ACH -- which i chose only b/c it seemed like a good adapter going from McNeil videos and not for Backtrack/Kali stuff which seems to be its common use ;p -- and the tp-link WR802N travel router i chose are 2x2 MIMO... which i just learned about.

The way I understand it, i apparently can't just go and replace one antenna with a yagi or whatever becuse it seems MIMO requires the antennas to be paired and at a specific distance to eachother, ie: they need to work together..

Quote

from networkengineering.stackexchange.com:

What this means is that if you have one antenna inside and one outside, you will either have single spatial stream data rates either inside or out, but then no connectivity in the other location.

In the situation you describe, 802.11n won't work.

 

I'm going to have to figure out how to proceed from here, as this is what i was hoping for the TP-Link in the house

 

[Admin 2545]

,,,see this...

,,,the Batwing antenna CAN ALSO BE DIRECTIONAL...!!!

[Akinetopsia 0]

2 minutes ago, Admin said:

,,,see this...

,,,the Batwing antenna CAN ALSO BE DIRECTIONAL...!!!

Ah! sorry! quickly going through the thread i see that using a single "wing" is possible

So many options to try

I still need to figure what i'll do re MIMO. Every 150mps adapter i find seems to have low power output, which probably is the same as the cheap adapter i currently have

[Dr. Pepper 58]

I think you don't need a mimo configuration. A simple P2P connection is enough to send a few signals to your equipment. When a cantenna is to big, then perhaps a batwing with simple reflector or a slot dipol (Sputnik) should be the way to go. Another possibility would be a simple biquad. All these can be relatively small and fits in a small plastic container. You then only need two network adapters like the alpha card and attach a good antenna on both. One is a hotspot like on your computer one is connected to this from the telescope. 

 

When you can etch pcb's you could also try a pcb biquad. Should be the easiest task to do then. I think 9db gain should be plenty for your application when used on both sides.

 

 

[Akinetopsia 0]

Thanks everyone!

 

I'll definitely try other options -- but since i was a bit short for time and already had started messing with the design i had i went ahead and modified the tp-link to allow external antennas. It seems to be working well with two antennas oriented in 45deg "V" position (better polarization variety i read?) and looks fairly directional -- i tested it by aiming at a building through a window about 2 blocks away, but it's hard to tell in the city.

I didn't have time to complete and 3d print the enclosures i designed for it, nor as the mounting clips, but either way i'm going to give it a try tonight - no observation, just testing in-situ.

 

That tp-link is tiny, love it. Still waiting for the alfa.

Edited November 26, 2022 by Akinetopsia

[Akinetopsia 0]

oh yeah, i forgot: directional antennas apparently do have range in the opposite direction -- so the tp-link does function well as a repeater with those on.

... or maybe my crappy DIY antennas just aren;t directional much after all ..

Anyway for me it's a fun occasion to learn. I'll know if it does anything at all tonight. I'll post the verdict once i'm back

 

Thx again!

Edited November 26, 2022 by Akinetopsia

[Admin 2545]

,,, the dimensions of this antenna seem to be not the best...

[Akinetopsia 0]

14 hours ago, Admin said:

,,, the dimensions of this antenna seem to be not the best...

After some tests that does seem to be the case. i just ran with the first design i could make in time for this weekend
I did some random tests to see if i could pick other access points nearby .. well, far, but around the area and direct line of sight and it didn't pick up much.

I mean it did work for my use case tho, and well enough for me to use the remote desktop with no stuttering nor lag, i could trigger image captures and have real time previews with no issue whatsoever which is great! The raspberry wifi monitor was reporting 55-65% connection strength vs 20-40% and constant dropouts and connection losses before

However, that was with the cheap low-power adapter out in the field, and being nearly winter now, the tree patch that's in the way has lost all its foliage so there is a lot more air gaps with more or less direct line of sight.

It feels like it could be better, and most likely will when i get the alfa to replace the cheap adapter, but now I have some time to try the other designs that were suggested.

Edited November 28, 2022 by Akinetopsia