AWR eBooks

RF Electronics Chapter 2: Computer Simulation Page 42 2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0. Figure 2.52. Initial Bandpass T matching network model. When one needs to develop a model of an unknown network, impedance measurements will need to be made between all terminals of that network and a table similar to the one shown in table 2.3, for the impedances of figure 2.51, is then produced using those measurements. To develop a model of the network, the same trial guesses for the component values as shown in figure 2.48 are used, as shown in figure 2.52. As before these initial guessed values, will change during the network optimisation. To import measured data, a spreadsheet containing the measurements is normally imported as a data file. As AWR DE does not easily recognise frequency units other than Hz, when.txt data files are used, it is easiest to use Base Units (Hz, Henry and Farad) for the error calculations. As a result, the measurements that are imported as data files may need to be changed to contain Base Units values. A Text Data file is imported in the same way as Touchstone files, by right clicking on Data Files and selecting Import Data File or by using the Project Add Data File Import Data File dropdown menu. Again, it is worthwhile to add some comments and headings with each line starting with a "!". In this example, the impedance data produced as table 2.3 is used as the measurement file. It is slightly more difficult to use a text data file in AWR DE than it is to use a Touchstone file. This data can be imported into the project, using the following equations 2.6 in the global definitions: Eqn. 2.6 MeFreq, are the measurement frequencies, MeP1Z11M is the measured Port 1 impedance magnitude, MeP1Z11Ph is the measured Port 1 impedance phase and so on. These variables can now be used, to set up the error equations shown in figure 2.53, which correspond to a normalised difference between the measured impedances and those obtained from the impedance seen at ports 1 to 3. In figure 2.53 EP1Z11M is the error for the magnitude of Z11 for Port 1, MeP11Z11M is the measured value of the magnitude of Z11 for Port 1and MoP11Z11M is the magnitude of Z11 for Port 1 of the model. EP1Z11P is the error for the phase of Z11 for Port 1, MeP11Z11P is the measured value of the phase of Z11 of Port 1 and MoP11Z11P is the phase of Z11 for Port 1 of the model. MeP1Z11M = Col(datafile("Measurements"),2) MeP1Z11Ph = Col(datafile("Measurements"),3) MeP2Z11M = Col(datafile("Measurements"),6) MeP2Z11Ph = Col(datafile("Measurements"),7) MeP12Z11M = Col(datafile("Measurements"),4) MeP12Z11Ph = Col(datafile("Measurements"),5) MeFreq = Col(datafile("Measurements"),1) RF Electronics: Design and Simulation 42 www.cadence.com/go/awr

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