Perform Transient simulation based on IQ measurement

This manual describes the procedure for using IQ measurements obtained from IQSTAR software to perform transient simulation. The transient simulator in VISION allows for obtaining the time domain response of a non-linear circuit excited by a modulated complex signal which can then be compared to measurement data from IQSTAR.

To begin this task, you will need:

A licence of VISION System Architect. See Installation and licence setup.
To have opened a schematic. See Create or select a schematic
An extracted U-HF-HPA model in Device model. See Extract U-HF model

The basic steps to perform a transient simulation based on IQ measurement files are:

1. Load an .imx file contained in the data_example directory of Vision using the import button:

Figure: Loading *.imx IQ file
When loading the *.imx file, a GUI allows you to choose whether to use the ideal reference file or the measured one as an eAWG source data. This choice allows access to the file loaded by the VSG (reference) or the one measured by the VSA.

Figure: GUI allows the selection of an ideal reference or a measurement-based
Automatic implementation of the transient-type simulation template.

Figure: Schematic generated after loading *.imx IQ file

The *.imx file loading process analyzes the data contained in it. It is then able to extract a number of ASCII files understandable by the AWG-VS source component. It associates these IQ files with the average power actually measured by IQSTAR.

Figure: Sweep block obtained by loading the *.imx IQ file

The analysis of the *.imx file also makes it possible to identify the characteristics of the IQ data needed for the simulation. Namely, the carrier frequency Fc, the number of measured samples, the sampling time step, the symbol rate, the roll-of used by IQSTAR, and more. These data are found in the equation block:

Figure: Equation block obtained after loading the *.imx IQ file
4. Click on the HPA device and choose the HPA_Imx.head. Now use the simulate button to run the model simulation with a test signal obtained from the measurement process.

Figure: Simulation Console
5. The first simulation results are accessible from the "Output Graph" tab

Figure: Simulation result Viewer

The simulation results are used to evaluate the response of the DUT. However, if the wish is to compare measurements and models directly, in that case, using the Whiteboard through its specific loading of IQ data, "Perform Comparison between Transient simulation and IQ Measurement" is advisable.