• State Verified Answer
  • Locked Locked
  • Replies 6 replies
  • Subscribers 67 subscribers
  • Views 4903 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 103838
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

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

Parents
  • 0

    Hi,

    Just to clarify: If the antenna is not 50 ohm in the 2.4GHz domain, it does not mean that you will get an output on a different frequency. It just means that the impedance match is off, and the performance (the radiated effect) in the 2.4GHz domain will be reduced because the resonance frequency of the antenna is not 2.4G.

    If the module is pre-qualified, tuning the antenna will not require a re-qualification.

    When you mention a shift of 150 MHz, what is the impedance of the antenna in 2.4/2.44/2.48 GHz? Note that the antenna shall always be tuned in it's application, meaning that if it's a heart rate monitor, it should be located inside the final housing and put up against your body when doing antenna related tuning.

    We have a white paper on antenna tuning that may be of interest: www.nordicsemi.com/.../89766141

    Cheers, Håkon

Reply
  • 0

    Hi,

    Just to clarify: If the antenna is not 50 ohm in the 2.4GHz domain, it does not mean that you will get an output on a different frequency. It just means that the impedance match is off, and the performance (the radiated effect) in the 2.4GHz domain will be reduced because the resonance frequency of the antenna is not 2.4G.

    If the module is pre-qualified, tuning the antenna will not require a re-qualification.

    When you mention a shift of 150 MHz, what is the impedance of the antenna in 2.4/2.44/2.48 GHz? Note that the antenna shall always be tuned in it's application, meaning that if it's a heart rate monitor, it should be located inside the final housing and put up against your body when doing antenna related tuning.

    We have a white paper on antenna tuning that may be of interest: www.nordicsemi.com/.../89766141

    Cheers, Håkon

Children
No Data
Related