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If you want to plot contours
Load_Pull > G_LPCM plots contours
Load_Pull > G_LPCM_A plots contours aligned to a specified value (like 1 dB compression)
Load_Pull > G_LPCM_C2 plots the intersection between two contours
If you want to plot contour interpolated min or max values
Load_Pull > G_LPCMMIN plots the contour min value
Load_Pull > G_LPCMMAX plots contour max value
If you want to plot a single contour at a specified value
Load_Pull > G_LPCM_V plots a single contour at a specified value
If you want to see the gamma points in your file
Load_Pull > G_LPGPM plots gamma points for a swept load impedance
If you want to plot swept data on a rectangular plot (like PAE vs. output power)
Data > PlotMD_R plots real data with an x and y-axis chose in the measurement (like PAE vs. output power)
I'm having a tough time plotting my data, how do I sanity check it?
- Plot the "pulled" gamma points (G_LPGPM)
- Do they look right (you should be able to visually confirm what they expect)?
- Are they the same for every independent variable value? (e.g. the gamma points are almost never a function of power, frequency, etc.)
- If the gamma points are wrong there's no point and looking any further at the data
- Plot the available input power vs. index for every independent variable value (PlotMD_R)
- Does it look correct (you should know the input power sweep range)?
- Are they the same for every independent variable value (e.g. the available input power is usually not a function of gamma, frequency, etc.)
- If the input power sweep is incorrect the source gamma data is probably incorrect and we can't properly compute anything that derives from input power (e.g. G_Trans, PAE, etc.)
- Plot the output power vs. index for each and every independent variable value (PlotMD_R)
- Does it look correct reasonable (e.g. physical and not fictional)?
- Plot the gain compression vs. index for each and every independent variable value (PlotMD_R)
- Does it look correct reasonable (e.g. physical and not fictional)?
- It's good to understand how hard the device was pushed so you have an idea of reasonable values for alignment
If all that looks good now you have a reasonable understanding of the gamma range over which the data was swept, the input power sweep, the output power of the device, and how hard the device was compressed.
The new load pull simulation script doesn't seem to auto-generate Graphs for me. Is that intended?
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Measured swept power load pull data often doesn't have a full power sweep at every gamma point. As a result, the contours plotted at a high input power point can look quite a bit different than the contours plotted at a low input power point because the number of gamma points over which the contours are plotting is different. For example, the traces below are show measured output power vs. input power for each gamma point. Note that not all traces are swept all the way to the highest input power. Contours plotted at the low input power level highlighted by the vertical red line cover the full gamma sweep in the data file because, as can be seen on the graph, all of the gamma points were swept to at least 21.7 dBm input power. The red circles on the contour graph below show the gamma points for the selected input power (i.e. the full sweep) and the contours cover the region highlighted by the red circles. However, when the input power is shifted to the highest available input power there is only data at ~60% of the gamma points. Thus, the resulting contours only plot over the region of the Smith Chart defined by the reduced number of gamma points. The red circles show the gamma points that were swept to the highest input power level while the grey circles show the gamma points which were not able to achieve the highest input power. The example that illustrates this issue can be downloaded here |
Why does my interpolated load pull data (LPINT) look strange at high power levels
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If the LPINT measurement shows "bad" results the cause is often that the load pull data is not very complete at high drive levels and, thus, LPINT is extrapolating outside of the remaining gamma sweep range. This is an extension of the reduced contour area case descibed in the question above.
Another way to diagnose this is to plot the gamma grid (G_LPGG) or convex hull (G_LPCH) at those power levels to see the reduced grid and that the matching network is now outside of the network, or simply use G_LPGPM and tune the power levels. For the above case look at the below gamma points low and high power levels and the subsequent match. Low Power Level Gamma PointsHigh Power Levels |
I love all this new load pull stuff but have some feedback; what's the best way to provide that?
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