Possible to fine-tune/offset frequency of radio (nrf51822) in code?

[davman]

Hi,

We're using an off the shelf module with a trace antenna that can't be modified. Measured the module once assembled, and due to surrounding plastic materials, the impedance of the antenna is not 50ohm resulting in the resonance frequency being shifted by ~150MHz.

As this is a fixed offset causing a drop in efficiency, I wonder if it's possible via SoftDevice to compensate to this by offsetting the radio accordingly.

System can run either SD 6.0 or 7.0, Bluetooth LE only.

best david

[davman]

Thanks for input Håkon, modules with dipole trace antennas are honestly only suitable for bigger products as any sensor / wearable and such will be too small that getting enough clearance around an antenna is impossible.

Back to my tuning question. Technically I guess this is actually doable if the SD could allow for setting relative offsets in the RF part, like calibration values that just compensates back a bit in software for modules making physical tuning impossible.