LimeSDR VNA(Memo)

Setup

sudo -s apt install python3-pip

sudo -s pip3 install Cython

sudo -s pip3 install setuptools

python3 setup.py install

sudo -s apt install libpython3.5

Execution

python3 measureVNA900M.py DUT20dB

 -> DUT file and short file will be generate.

python3 calculateVNA_900M.py DUT20dB

 -> DUT20dB.s1p are generate.

 

from s1p, calculate power(=20*log10(SRQT(i^2+q^2)) and phase(=atan(I/Q)).

However the data have bad duw to

- Directibity of coupler is not so good(=about 20dB)

- Lime has 180 degree phase jump

The VNA can measure only s11 log-mag( -20dB>)

 

freq[HJz] I[mv] Q[mv] Power[dB] Phase[degree]
890000000 -0.3207844778 0.1656117838 -8.849557909 -1.09421666
891000000 -0.320746235 0.1248143493 -9.26440117 -1.199689209
892000000 -0.33145192 0.09156823234 -9.272167867 -1.301255368
893000000 -0.3298455399 0.06659722632 -9.46025948 -1.371570401
894000000 -0.323988073 0.04586521932 -9.703245322 -1.430166261
895000000 -0.3176111542 0.01769844856 -9.948620591 -1.515130259
896000000 -0.3137158057 0.02579331231 -10.04001283 -1.488762122
897000000 -0.3123975193 0.02814374638 -10.07074286 -1.48094934
898000000 -0.3198297211 0.03133417552 -9.86013707 -1.473136559
899000000 -0.319007123 0.04898002654 -9.822799017 -1.418447089
900000000 -0.341734431 0.06622322869 -9.16612285 -1.379383182
901000000 -0.3412811236 0.07168561031 -9.150248832 -1.363757619
902000000 -0.3647781632 0.08259255915 -8.54229973 -1.348132056
903000000 -0.3651387116 0.09934108934 -8.440723564 -1.305161759
904000000 -0.3674497304 0.1015131313 -8.376619988 -1.301255368
905000000 -0.34211872 0.1002489499 -8.958712934 -1.28575188
906000000 -0.3425551609 0.1062162584 -8.906714661 -1.270126317
907000000 -0.3201771305 0.1076086631 -9.427409269 -1.246565898
908000000 -0.3150940205 0.1183821603 -9.457755423 -1.211408381
909000000 -0.3118271442 0.1116265427 -9.598066235 -1.227033944
910000000 -0.325873772 0.08185771054 -9.473275999 -1.324693712

Although Lime has phase 180 jump, calculateVNA.py fix the error????

https://github.com/myriadrf/pyLMS7002Soapy