Antenna for a Nordic Semiconductor nRF8001 Bluetooth Module

joeferner · May 21, 2015, 12:32am

I’m trying to design a board with a nRF8001 chip on it. I have no idea what I’m doing when it comes to antennas and RF for that matter. Does anyone have any tips on how to go about doing this. Should I try and create a PCB antenna or should I use an off the shelf chip antenna? I’ve watched the Contextual Electronics video on importing bitmap antennas but I’m not sure how to even go about creating a bitmap antenna to start with.

mcenhillk · May 21, 2015, 12:08pm

The data sheet for that chip should have an example layout that you use as a reference. you could also dig through Nordic’s app notes, I’m pretty sure they have a PCB antenna reference.

joeferner · May 21, 2015, 6:22pm

I found a reference design here (see the image below). I’m guessing the antenna is that trace around C5 and C6. This is the same design in the datasheet.

I also found a document on antenna tuning with lots of equations and the need for some expensive equipment.

Adafruit also has a design with a completely different antenna.

I may just copy the Nordic’s design, spin a PCB, and give it a try. But I’m not really sure how I would tests it’s efficiency.

StefanHamminga · May 21, 2015, 6:45pm

My pads version of the Texas Instruments Design Note DN007 2.4Ghz antenna:

github.com

StefanHamminga/SH_Antennas.pretty/blob/master/TI_DN007_2.4GHz.kicad_mod

(module ANTENNA_TI_AN0007_2.4GHz (layer F.Cu) (tedit 543CD76F)
  (attr virtual)
  (fp_text reference ANT1 (at 0 -2.5) (layer F.SilkS) hide
    (effects (font (size 0.6 0.6) (thickness 0.127)))
  )
  (fp_text value Antenna_PCB_type (at 6 2) (layer Cmts.User)
    (effects (font (size 0.7 0.7) (thickness 0.15)))
  )
  (fp_text user ANTENNA (at 6 0) (layer Cmts.User)
    (effects (font (size 1 1) (thickness 0.15)))
  )
  (fp_line (start 14 -3.76) (end -14 -3.76) (layer F.Fab) (width 0.05))
  (fp_line (start -14 -3.76) (end -14 3.76) (layer F.Fab) (width 0.05))
  (fp_line (start -14 3.76) (end 14 3.76) (layer F.Fab) (width 0.05))
  (fp_line (start 14 -3.76) (end 14 3.76) (layer F.Fab) (width 0.05))
  (pad 1 connect rect (at 0 -2.545) (size 25.38 1.21) (layers F.Cu F.Mask))
  (pad 1 connect rect (at -7.11 -2.045) (size 7 2.21) (layers F.Cu F.Mask))
  (pad 1 connect rect (at -11.7 -0.065) (size 2.18 5.97) (layers F.Cu F.Mask))
  (pad 1 connect rect (at -7.7 2.375) (size 9.98 1.29) (layers F.Cu F.Mask))
  (pad 1 connect rect (at -4.21 0.465) (size 3 1.21) (layers F.Cu F.Mask))

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