[sharing] custom designed NRF24 module with PIFA


#1

Hello, this is my design of custom antenna nRF24 module.
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for better detail please see the achievement .

based on schematics from Nordic company
replaceable with nRF24-module (nRF24L01) from market ,
In need of better radio range.

NRFbd3-meanderedPIFApaper.fzz (83.7 KB)

Featuring special usage of:
(The usage below should not be familiar to normal users, it is unusual and you need to know what you are doing)
A. special designed PIFA (printed inverted “F” Antenna) with different shapes.
B. with some technique Fritzing can make some part of solder-mask blocked, (see completed PCB - back side), this is done in order to yield better radio range, but seems copper mask doesn’t matter much.

C. Castellated Holes designed to cut manually ( safe some cost)

here’s how I did this:
(A)

  1. use many "via"s for precise locating, wire them up.
  2. convert via to bend point
  3. you may need to pull and ctrl+z to make them look nice.
    (you can see the designed antennas in the sketch)

(B) (use copper pads as mask-block, and export twice for different needed file)

  1. export using pads to cover up place where you want to show the copper/FRP naked
    (in my case, ground fill was used, and mask-block also blocks ground fill)
  2. find “maskBottom.gbs” and/or “maskTop.gts”, back them to somewhere else
  3. remove the pads used for mask-block, export again.
  4. copy the make file from step 2. and paste&replace them in later export.

© (Just some more holes extend over extra board space.)
the board was ordered in 0.8mm thickness for easy cutting.

this links to my FB-fanpage posting this project


and the bigger boards at left were the MCU(atmega328p) board for mounting /controlling nRF module. there were also mask blocks on them.

this design did made some small patch sample out,
SMD with stencil&paste by hand, and cooked by heat-plate usually used to grill .
The yield of the product is bad, not all worked.
However small amount of them did work with all function, radio.begin and all write&read.
that’s a sign of success design I guess.

I didn’t make big patch out of these, because my yield was poor,
and too much hassle for me to earn a little more range.
also good RF range seems consider more on capacity value than PIFA shape,
or a bigger antenna is needed. ( room availability is strict with my project)
Far beyond my skills, for now. Still I had some fun with this project.
And the working samples were reeeeeally cool to show around maker friends.
“hey look I designed my own antenna, and it Fking worked”

Hope this experience and usage can inspire you guys :slight_smile:


#2

It would be more useful to make these antennas as parts so people could just add them to their module of choice. That would also cut down on the vias which I expect are probably causing reflections back to the source due to the holes for the via. I wouldn’t expect solder mask to affect RF particularly (although I’m not an RF expert), but tricks (invisible copper) in a part can surpress the solder mask when desired (that won’t work in a sketch as far as I know).

Peter


#3

at my design I usually left the start and end via so I can drag the entire antenna together,
and after locating I’ll remove the vias.

I think people can experiment their own antenna design and not by using the same,
such as a looped dipole antenna (which I also tried, but effect is not good probably due to capacity needed is different)
here just showing possibility to do that.
its still much easier to use one in mass-productive market, and even cheaper.