I’m attempting to use SoapyLMS7 to gather some data from one of these couplers and a log-periodic antenna, similar to the VNA example, but there doesn’t appear to be any consistent phase coherency by default when using Soapy. I would expect the phase difference to be the same over two separate frequency sweeps using the same device, but instead I am getting two vastly different results:
The phase difference here is the TX phase minus the RX phase, using the coupler’s reflected and -30 dB coupled ports, going into LNAW 1 and 2.
I’m really unsure of what’s going on here, but my best guess is that the issue could be that Soapy is starting the LimeSDR in FDD mode? If that is the case, is there any way to use TDD mode using SoapLMS7? Thanks for any insight you can provide, and apologies if any of this doesn’t quite make sense, I’m still trying to piece it all together.