we’ve designed a tracer module for an indoor localization task based on DWM3210 modules. The modules are connected to SMA connectors by an 12mm straight connection. Onto the SMA connectors we’ve installed UWB antennas but the connection between the tracer and beacon is only stable for 2-3 meters.
We’ve also tested the system with the fully integrated DWM modules with onboard antenna. In this configuration we had a stable connection over 20+ meters what lead us to the conclusion that the antennas might be the issue.
Does anybody have a recommendation for SMA antennas?
Did you check the matching of your UWB antenna on a VNA?
On your module you could have excessive insertion loss in the transition from the chip to the SMA connector.
Is the integrated module you are comparing with your own, or off-the-shelf like DWM3001C or DMW3000?
There are antennas specifically designed for UWB frequencies 6–9 GHz. e.g. KyoceraAVX 1005193-B02 or Taoglas UWCD.20
sadly we don’t have a VNA to measure the signal quality
For our reference we used an DMW3000 off-the-shelf module and it worked fine. On our own tracer we’ve installed KyoceraAVX 1005193 antennas.
If the bad signal quality is caused by the onboard connection to the SMA connector what kind of connector would you recommend instead?
The layout of the transition to the SMA connector will depend on your stackup, PCB thickness and the connector used.
See this link for example for a transition from a 4 layer board: SMA Edge Connector Transitions in an RF PCB