Hello there,
we use the DW1000 on self-designed PCB`s for a tranceiver and a receiving anchor which work in TDOA.
In order to fullfill certain EMC-compliances, we found out, that we are facing problems when having electromagnetic interference between 24MHz and 74MHz radiatet at the device.
The result is, that we have no radio-connection between the two devices.
Here is a picture of the pcv-design on the transceiver.
Is it possible to receive the disturbing waves throug the UWB-Antenna, which the causes the DW1000 not working properly anymore?
We where thinking of using frequency-filters between the Antenna and the DW1000.
Did anyone ever faced problems like this?
Best Regards
Worth narrowing the coupling path before adding filters:
- Antenna coupling is unlikely. At 24–74 MHz the UWB antenna is electrically tiny and a poor match, it’s not an efficient receiver that low.
- Suspect the 38.4 MHz reference crystal instead. Your interference band straddles this clock and its harmonics/sub-harmonics. Coupling into the crystal circuit (radiated or via ground/power) can jitter the internal PLL and break the link, this matches your symptom better than antenna desense.
- Check conducted paths too, power lines, SPI/digital traces, and cable harnesses can pick up VHF energy and carry it onto the board.
- Confirm with a near-field probe, over the crystal/PLL/power section before deciding on filters bandpass filters on the antenna line won’t help if the real path is conducted or crystal-coupled. Ferrite beads/common-mode chokes on power/digital lines plus a tighter ground guard around the crystal would be the fix if that’s confirmed.
If you’d like this properly diagnosed and validated, our EMC lab handles this kind of work, feel free to reach out via stancermtl.com.
