Waveform

The Waveform calculation allows you to compute and display the waveform of analog and digital signals after passing through a transmission line. This calculation type is available for all transmission line types.

Example

• Example - Calculate Signal Waveform

Waveform Calculation Walkthrough

To perform a Waveform calculation, follow these steps:

1. Set the initial calculation settings:

   • Set Target to Transmission line
   • Set Target type to Single-ended, Diff pair, Coplanar single-ended, or Coplanar diff pair
   • Set Mode to Time domain
   • Set Parameters to Waveform
   • Set Signal type to Digital or Analog

   

2. Select the required transmission line model and review it in the preview area.

   

3. Define the input parameters for the transmission line.

   

   Available parameters are listed below. Some of them may not be available for certain transmission line types.

   • H – Dielectric thickness (mm). For each dielectric layer, you can specify its own thickness using the H1..H4 parameters (the number of H(n) parameters is determined by the number of dielectric layers).
   • Er – Dielectric constant. For each dielectric layer, you can specify its own dielectric constant using the Er1..Er4 parameters (the number of Er(n) parameters is determined by the number of dielectric layers).
   • W1 – Trace width (mm).
   • W2 – Trace width after undercut (mm).
   • T1 – Trace thickness (mm).
   • C1 – Coating thickness (mm).
   • CEr – Coating dielectric constant.
   • D1 – Distance from the trace to the reference plane (mm).
   • S1 – Diff-pair trace spacing (mm).
   • TC – Conductor conductivity (S/m).
   • tgδ – Loss tangent.
   • LTL – Line length (mm).
   • FREQ – Frequency (MHz).
   • ZS – Source impedance (Ohm).
   • ZL – Load impedance (Ohm).

   Digital signal parameters:

   

   • Y2 – Signal amplitude (V).
   • TR – Rise time (ns).
   • TF – Fall time (ns).
   • PW – Pulse width (ns).
   • PER – Period (ns).

   Analog signal parameters:

   

   • YAMPL – Signal amplitude (V).
   • PHASE – Signal phase (°).

   Surface roughness parameters:

   • a – Nodule radius (µm).
   • N – Number of nodules in a unit area.
   • Af – Unit area (mm²).

4. Click Calculate in the lower-right corner of the calculation tab to run the calculation.

   

   Before running the calculation, you can click the dropdown arrow next to the Calculate button to choose between two calculation saving options:

   

   • Overwrite calculation – Saves the modified input parameters to the current calculation, overwriting previous data.
   • Save as new calculation – Saves the modified input parameters to a new calculation. This calculation will appear in the Projects panel.

Calculation Results for Single-Ended and Coplanar Single-Ended Lines

You can view the calculation results in table and graph formats at the bottom of the tab. The results show the Voltage (V) and Magnitude (dB) signal parameters as a function of time.

To choose which parameter is displayed in the graph, use the Axis Y setting in the Calculation results panel.

Calculation Results for Differential and Coplanar Differential Lines

The results show the Voltage (V) and Magnitude (dB) signal parameters as a function of time.

To choose which parameter is displayed in the graph, use the Axis Y setting in the Calculation results panel.

For differential lines, waveform parameters are calculated in two display modes: Differential and Common. You can choose the required display mode in the Calculation results panel.

See Also

• Example - Calculate Signal Waveform