File Description:

All data from a particular experiment is in a main folder that bears the name of that experiment. Under the Experiment name directory, there is a subfolder called ‘RawData’, which contains all the setup and data files for that particular experiment. All of them are ASCII files. The file ‘SPECTRUM_ANALYZER_SETUP.DAT’ indicates the test parameters and the signal measurement type for each channel and trace number. The file ‘POSITIONS.DAT’ indicates the (x,y)-coordinates of each scanner position in inches.  The 201 stepped-frequency values are listed in the file ‘FREQUENCIES.DAT’ (units are Hz). Each data file is labeled with the position number of the scanner, the channel number and the trace number of the spectrum analyzer data.  For example, ‘POS0010_CHAN1_TRACE0004.DAT’ would indicate scanner position 10, Trace 4 on channel 1.  

Each trace was set up as a Smith Chart in order to measure both magnitude (dB) and phase (degrees). For each trace, the network analyzer considers magnitude to be the ‘primary’ measurement and the phase to be the ‘secondary’ measurement. As a result, each data file contains 402 floating point numbers, corresponding to the 201 frequencies, in the following format:

      Primary Point 1, Secondary Point 1, Primary Point 2, Secondary Point 2, ... 

These numbers are stored (in the scientific notation) as a continuous string of ASCII characters with comma's separating each of the 402 numbers. In Matlab, one can read data from such files using the ‘CSVREAD’ command.

The file ‘POSITIONS.DAT’ indicates the coordinates of each scanner position in inches.  The center-to-center separation between the Port 1 and 2 antennas on the scanner carriage is 10.5 inches. The (x,y) coordinates of the positions of antenna 1 and 2, corresponding to each scanner position, can be computed as follows:

x-coordinate of port 1 antenna position: x-coordinate of scanner position – 42.25 inches
y-coordinate of port 1 antenna position: 41 inches – y-coordinate of scanner position
x-coordinate of port 2 antenna position: x-coordinate of scanner position – 31.75 inches
y-coordinate of port 2 antenna position: 41 inches – y-coordinate of scanner position

Coordinates of antenna 3= (-54.75 inches, 32 inches) 
Coordinates of antenna 4= ( 54.75 inches, -32 inches)