nRF15822 - Antenna tunning with SDR

[Jose Xavier]

Hi, I was thinking if it is possible to use, per example HackRF greatscottgadgets.com/.../, to tune the antena of the nRF15822 seeing if it is transmiting on the 2.4Ghz frequency or if it is not. What do you think?

I'm asking that because I got very poor range with my own board even with tx power on max and 250kbits data rate, I get some 10 meters in LOS otherway only get some 3/4 meters.

Schematic - nRF15822-nRF15822.pdf

[Asbjørn]

Looking at the screen shot you've attached here I don't think you'll get much extra performance out of tuning the antenna. I believe the loss in link budget is due to the component placement of the matching network. The discrete components from the three pins VDD_PA, ANT1 and ANT2 towards the antenna works as a DC feed, balun, impedance transformation and filter. That's why it's really important to follow our reference layout and schematic closely. You're layout deviate from this and hence I do believe you would not get all the output power from the chip that you could into the antenna. You could potentially see some improvements by tuning the matching network component values. Have a look at this white paper. Remember that the matching network also filters the harmonics and spurious and that if you want to sell this as a product you must meet the regulatory requirement for the region you want to sell this in.

For tuning the antenna I would recommend you to have a look at this document as well.

[Jose Xavier]

Thank you, I'll redesign it to make it similar to your reference. I'll also read the documents you shared! If I share the design after redesign it can you take a look again?

Thank you

[Jose Xavier]

Hi again, I redesign the board to follow the developmento board:

http://i.imgur.com/glCy9Hp.png

Do you think it is better now? I tried to match it as possible with the development board.