Hello,
I have a custom board based on a nRF9160 SiP. It uses a shared antenna for GPS and Cellular, based on this : https://infocenter.nordicsemi.com/index.jsp?topic=%2Fnwp_033%2FWP%2Fnwp_033%2Fnwp_033_intro.html
I use a SMA connector, which is accessible to the end user. The antenna can therefore be removed.
I noticed that the power consumption profile was very different when the antenna is mounted and when the SMA remains "open" (no antenna). Not only the power draw is higher, but it's also very spiky ... which is not appreciated by the battery I use, and causes the device to reset because the voltage drops.
I attached a log, where the device turns on cellular, connects to nRFCloud, sends and read data.Note that in both cases (with and without antenna), the operation succeed because network coverage is good where I am.
I would like to know if this is an expected behavior ?
If so, is there a way to detect whether an antenna is connected or not ? Ideally, I need to detect the antenna presence prior to enabling cellular, but this might no be doable.
Maybe using SNR or something similar ? But I believe this would require the device to be already connected to the network ?
I found this documentation, but my hardware does not implement the required components/traces. https://docs.nordicsemi.com/bundle/nwp_033/page/WP/nwp_033/nwp_033_antenna_detect_magpio.html
Thanks !