We are currently using the Ai-Thinker BU01 and DWM1000 in our anchor design, integrated with an ESP32. The system is powered via PoE, with an additional USB Type-C input option.
This is the third revision of our hardware. Across revisions, we have significantly improved the PCB layout. The current design uses a 4-layer PCB (65 mm × 65 mm), with RF sections (Wi-Fi and UWB) properly isolated. The bottom layer is a solid ground plane, and we have included selective solder mask openings to aid heat dissipation. Additionally, there is a dedicated internal ground plane to help distribute heat more effectively. The enclosure is plastic and not IP-rated.
From a firmware and functional standpoint, the system is operating correctly. However, we are observing a temperature rise of approximately 20–25°C in the module during continuous receive mode.
We measured the current consumption in this mode to be around 178 mA, which matches the datasheet-listed specification. Upon further inspection, we noticed that both the BU01 and DWM1000 modules do not provide a ground pad or exposed thermal pad on the bottom side for efficient heat transfer to the PCB.
Given these observations, we would like to understand:
- Whether this level of temperature rise is expected under continuous receive operation, and
- If there are any recommended design practices or mitigations we may be missing to improve thermal performance.