IQ Sampling without antenna array

[SDK_User_771]

Hi,

I got a question on IQ Sampling with the direction_finding_connectionless_tx/rx example.

Settings:

Sample Spacing = 125 ns

Sample Sapcing (Reference Period) = 125 ns

DFEPACKET.MAXCNT = 656

CTE Length = 160 us

Switch Slot/Sample Slot Length: 2 us

=> Number of Sample Slots: 37 

So 1 Sample/125 ns means 16 Samples/2 us Sample Slot and additionally 64 Samples during the reference period.

Problem:

Without the guard period and the switching slots, I should be able to get  (Number of Sample Slots)*16 + 64 Samples, which evaluates to 656 Samples with 37 Sample Slots.

But I only get 101 Samples. 

I am not using an antenna array (so only the chip antenna should do the sampling) , and have reduced the number of antenna patterns to {0x1, 0x2, 0x3} since 3 are mandatory for the code to work. My assumption is that still some antenna switching is performed in the code and I am looseing samples to that. 

Question:

What are the correct settings to get IQ samples only from the chip antenna, and if this is not possible, how can this number of 101 Samples be explained that I receive ?

(I also don't necessarily need the  IQ  samples in the context of direction finding, so I am also happy with a solution that disables the funcionality of this feature.)

Best regards 

[Simonr]

Hi

I don't think you'll be able to disable the switching periods etc. while using the Direction Finding sample applications like this, but I have asked the developers internally if they have any clever ideas to purely maximize the number of IQ samples you can achieve.

AFAIK the only documentation we have on doing this manually is the Direction Finding whitepaper that shows you how to set up every part of IQ sampling separately, so if you set up IQ sampling without antenna switching from scratch that would be my guess as to what the best procedure forward would be. I'll let you know if I hear anything from the developers on the matter.

Best regards,
Simon