Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Select Help > Open Examples... from the menus and type either the example name listed above or one of the keywords below.

Or in Version 13 14 or higher you can open the project directly from this page using this button. Make sure to select the Enable Guided Help before clicking this button.

...

Swept Load Pull Measurements 

 

NOTE:   FOR A MUCH MORE COMPLETE EXAMPLE OF WORKING WITH SWEPT LOAD PULL DATA SEE THE “Swept"Swept_Load_Pull_Measurements_Complete.emp” emp" EXAMPLE  

  

Overview  

  

This example is intended to show the functionality of the Load Pull Measurements utilizing the swept load pull file format, otherwise known as Generalized MDIF (GMDIFD). This project is setup such that the Circuit Schematics node in the Project Browser has specific data displays, where related graphs and measurements are grouped together. The data displays are numbered 1 through 4 and should be worked through in this same sequence. Each number schematic contains notes to guide you through the operation of the marker defined reference.

A full listing of measurements’ measurements' functionality and intended use is listed at the end of the document. A list of measurements used per data display is also provided in the following sections to aid you in future setup of these same coupled measurements.

Data Display Schematics  

   

  

1_Contours

This schematic contains two three graphs that are tied together through the use of a defined marker reference.

Input Power vs Index plots the input power in dBm against the input power’s power's sweep index. A marker m1 is defined on this graph for use in the Output Power and Efficiency Contours graphand Output Power and Efficiency Contours Rectangular graphs.

Output Power and Efficiency Contours uses several different Load Pull measurements, plotting different PAE and Pload data. The maximums of PAE and Pload (G_LPCMMAX), as well as general stepped contours for each measurement (G_LPCM) are also plotted. Displaying contours at specific values (G_LPCM_V) is also shown, as well as the over lapping region between PAE and Pload at specific values (G_LPCM_C2).

Output Power and Efficiency Contours Rectangular shows the same data as the Output Power and Efficiency Contours graph but on a rectangular real/imag graph

List of Load Pull Measurements Used: 

G_LPCMMAX 

G_LPCM 

G_LPCM_C2 

G_LPCM_V 

PlotMD_R

...

2_Rectangular_Plots

...

List of Load Pull Measurements Used: 

G_LPGPM 

PlotMD_R

...

3_Aligned_Plots

This data display is meant to show the functionality of the alignment based load pull measurements.   Aligning is the process of adjusting the load pull data such that all the values that achieve a given metric are aligned at the same x-axis index.   In other words, data aligning allows the user to plot contours at a fixed output power level, PAE, compression, drain current, etc.

...

Gain Compression From Max Gain for Aligned Comparisondisplays gain compression (defined from max gain) vs. output power for every load impedance (PlotMD_R).   The active (blue) trace is defined by the marker position in the Gamma Points and 4 dB Compressed Contour  graphgraph.   The horizontal line marks 4 dB compression and shows that not all impedance points allow the power sweep to reach this compression level.

Gain Compression from Max Gain Aligned to 4 dB Compressed displays gain compression (defined from max gain) aligned to 4 dB versus sweep index (PlotMD_R_A).   The active (blue) trace is defined by the marker position in the Gamma Points and 4dB Compressed Contour graph.   This graph shows that the data is nicely aligned at index = 14 and that contours (or any other plots) made at that iPower point will be the equivalent of a load pull done at a fixed 4 dB compression.

PAE and Output Power Contours at 4dB Compressed displays the output power and PAE contours at the specified gain compression level (G_LPCM_A).   The bold output power contour shows a 42 dBm value (G_LPCM_VA) and the bold PAE contour shows a 65% value (G_LPCM_VA) and are also outlined with their intersection or overlap region represented in red (G_LPCM_C2A). Importantly note that the iPower selection for each measurement is set to Auto Align.   This means the correct iPower index will be set automatically, corresponding to the value chosen in the Align to specify value (dB) box.

List of Load Pull Measurements Used: 

G_LPGPM 

G_LPGPM_A 

G_LPCM_V 

G_LPCM_VA 

G_LPCM_C2A 

G_LPCM_A 

PlotMD_R 

PlotMD_R_A

...

Reference Material - Graphically Viewing Load Pull Data

Load pull data can be viewed via measurements.   These measurements are found under the “Load Pull” "Load Pull" heading.

G_LPCM: This commonly used measurement plots the contours of the selected calculated quantity and is intended to be used with the Smith Chart.   The data file, calculated value to plot, contour step size, max number of contours plotted, characteristic impedance and sweep reference must be specified.

...

G_LPCMMAX: This measurement plots the maximum value of the selected calculated value and is intended to be used with the Smith Chart.   The data file, calculated value to be plotted, and characteristic impedance must be specified along with a specified sweep reference.

G_LPGPM: This measurement allows you to view the reflection coefficient (impedance/gamma) points the swept load pull data was taken at.   This measurement is used with the Smith Chart.   The characteristic impedance with which the reflection coefficients are normalized must be specified (defaults to 50 ohms).

...

PlotMD_R: This measurement allows the visualization a real-valued data from a swept load pull file. This includes calculated values, such as PAE, which can be selected from the measurement dialog.   

PlotMD_R_A: This measurement allows the visualization of real-valued data from a swept load pull file aligned to a specific value of a calculated quantity, for example plotting efficiency aligned to the 1dB Compression point.

...