How do you plot the following ASCII file values into a smith chart
Asked by Dimitris on 10 Aug 2012
Latest activity Commented on by Star Strider on 10 Aug 2012
Hello I have been using an RF Vector Network analyzer tool to get some values from an RF experiment on antennas that i have done. The VNA saves the values only in ASCII format.
Does anyone know how to plot these values back to a smith chart. They are S11 parameters for some antennas i have build. These are the values format as loaded to matlab using load "filename.S1P
! HP8714C: C.04.50
! Reflection Data:
# MHz S RI R 50.0
0.300 -0.9961853 0.06274414
0.358 -0.9934387 0.07763672
0.417 -0.9972839 0.0786438
0.475 -0.9948425 0.09298706
0.534 -0.9908752 0.1139832
0.592 -0.9890747 0.1188965
0.651 -0.9916992 0.1288757
0.709 -0.9866943 0.1340637
0.767 -0.9827576 0.1525269
0.826 -0.9825745 0.1593323
0.884 -0.9830017 0.1655273
0.943 -0.9816589 0.1826782
1.001 -0.9760742 0.191803
1.059 -0.9742432 0.1988525
sorry for the long post.
The 50 is the resistance of the RF VNA.
And the three collum are the frequency angle and magnitude i think. Sorry for the log post and thanks in advance.
Products
No products are associated with this question.
1 Answer
Answer by Walter Roberson on 10 Aug 2012
Accepted answer
fid = fopen('filename.S1P', 'rt');
datacell = textscan(fid, '%f%f%f', 'HeaderLines', 3, 'CollectOutput', 1);
fclose(fid);
YourData = datacell{1};
Sorry, the use of the smith() or smithchart() function is not obvious to me.
Did you need to read the 50.0 out of the data file?
3 Comments
Dimitris on 10 Aug 2012
Hi thanks for the quick reply. I am kind of ne at malab so please be patient with me. I am inserting your code but nothing happens.
>> load TRACE0.S1p
>> fid = fopen('TRACE0.S1P', 'rt');
datacell = textscan(fid, '%f%f%f', 'HeaderLines', 3, 'CollectOutput', 1);
fclose(fid);
YourData = datacell{1};
how do i plot the data?
Walter Roberson on 10 Aug 2012
The data will be in the array YourData
As I already noted, I do not know how to use the smith() or smithchart() functions. I linked to the documentation for those, above, so you can read the documentation and figure out which is most appropriate.
Star Strider on 10 Aug 2012
I believe to use the Smith Chart, you need to have a complex vector. So it will be necessary to convert the magnitude and phase information to their complex equivalents to use it.
0 Comments