Perform CW simulation

How to perform CW simulation. A CW simulation only allows for taking into account the steady-state of the system response. The CW simulation considers that the envelope signal varies slowly over time, with regard to time constants of the system. A CW simulation is much faster than a transient simulation, however it is only possible for CW pulse type excitation, with constant (or slow) amplitude and frequency transition.

To begin this task, you will need:

The basic steps to perform a CW simulation are:

  1. Drag and drop the SIMCTRLR simulation controller block from the palette window in Simulation controls section to the schematic window.
    Figure: Simulation controller block


  2. Double-click on the SIMCTRLR block to open the Parameters window. By default, the Simulation name is "sim0" and it is editable. In the Simulation mode tab, choose the Simulation mode by selecting CW simulation. Choose the Analyse type by selecting Nominal analysis. In the Solver tab, choose the Solver Type by selecting Algebraic solver I.
    Figure: Simulation mode


  3. Now we will set up the schematic to simulate a HPA-U-HF model. Drag and drop the HPA block from the palette window in Non linear section to the schematic window. Double-click on the HPA block to open the Parameters window and fill in the Model parameter file field with the absolute or relative path of your extracted model in device modeler with the extension ".head".
    Figure: HPA block


  4. Drag and drop the CW-VS block from the palette window in Source section to the schematic window. Double-click on the CW-VS block to open the Parameters window and set the amplitude of the CW signal provided by the source. Here, we set -30 dBm. Connect the CW-VS block output [+] with the input [in] of the HPA block.
    Figure: CW-VS source block


  5. Drag and drop the DC-VS block from the palette window in Source section to the schematic window. We will use this block to indicate the carrier frequency of the CW signal to the HPA block. Double-click on the DC-VS block to open the Parameters window, change the signal type to "real signal" and set the carrier frequency in DC value field. For this example, the carrier frequency is 3 GHz. Connect the DC-VS block output + with the input fc of the HPA block.
    Figure: Set the carrier frequency


  6. Drag and drop the RES block from the palette window in Linear lumped section to the schematic window. We will use this block to present a 50 Ohms load at the output of the HPA block. Double-click on the RES block to open the Parameters window and set the resistance to 50 Ohms. Connect the HPA block output [out] with the input [+] of the RES block.
    Figure: Present 50 Ohms load at the output of the HPA model


  7. We will now place a probe to measure the output power of the model. In a CW simulation, we need to use the Pmeter block. Drag and drop the Pmeter block from the palette window in Probe section to the schematic window:
    • Place the Pmeter block between the HPA block and the RES block.
    • Connect the HPA block output [out] with the Pmeter block input [in].
    • Connect the Pmeter block output [out] with the RES block input [+].
    The Pmeter block measures amplitude of the incident power pin, absorbed power pabs and reflected power pref. Here we are interested in the incident power pin of the Pmeter block. Double-click on the Pmeter block to open the Parameters window and choose dBm as Probe type. Drag and drop the Waveform block from the palette window in Scope section to the schematic window and connect the Pmeter block output pin and the Waveform block input [1]. Double-click on the Waveform block to open the Parameters window, choose Real signal as Signal type and edit a probe name. Here we set "Pout".
    Figure: Pmeter block


  8. We will place a probe to measure the gain of the model. For the CW simulation, we need to use the RF Gain block. Drag and drop the RF Gain block from the palette window in Probe section to the schematic window:
    • Connect the RF Gain block input [in] with the HPA block input [in].
    • Connect the RF Gain block output [out] with the HPA block output [out].
    Double-click on the RF Gain block to open the Parameters window and choose dB Magnitude and Phase as Gain type to display outputs db(gain) and phase(gain). Drag and drop another Waveform block from the palette window in Scope section to the schematic window and connect the RF Gain block output db(gain) and the Waveform block input [1]. Double-click on the Waveform block to open the Parameters window, choose Real signal as Signal type and edit a probe name. Here we set "Gain".
    Figure: Waveform block


  9. Double-click on the SIMCTRLR block to open the Parameters window and edit a name to the simulation. Here we change the name for "sim0_HPA_U_HF". The model can now be simulated. In the menu bar of the workspace window, click on Simulate>Run simulation or on the shortcut . The output console is displayed:


    The console window contains the simulation time, the simulation mode, the repertory of the results, and also any warnings and errors encountered during the simulation.
  10. When closing the console window, simulation results appear in the application tree in the folder named after the simulation "sim0_HPA_U_HF". In Workspace window, the Log shows console information. Click on Output graphs tab to access the measurements provided by the probes.
    Figure: Output graphs