matlab-design-pcb-transmission-line

Use design(microstripLine, freq) from RF PCB Toolbox to auto-size the trace for 50 ohms at your target frequency, then verify with getZ0(ms). Assign a substrate like dielectric("FR4") and a conductor like metal("Copper") for realistic results.

Use microstripLineCustom with TraceType='Differential' and set LeftCoupledTraceGap or RightCoupledTraceGap to add aggressor traces. Compute S-parameters and extract NEXT/FEXT from the aggressor ports of the resulting 4-port or 6-port matrix.

RF PCB Toolbox objects like microstripLine use a 2D field solver that is accurate for loss, coupling, and arbitrary stackups. RF Toolbox functions like txlineMicrostrip are closed-form analytical approximations and should only be used when RF PCB Toolbox is unavailable.

The rlgc function requires finite conductivity, so you must assign a metal such as metal("Copper") to the Conductor property before calling it. The default PEC conductor causes the error "Conductivity value must be finite with 2D field solver."

Use pcb2D for fast per-unit-length RLGC and impedance extraction of uniform cross-sections, which runs in milliseconds. Use full 3D sparameters analysis for discontinuities such as bends, steps, and stubs.

This workflow requires MATLAB R2025a or later and the RF PCB Toolbox. Features like pcbBendCustom and pcbTraceCustom for bend and trace discontinuity analysis were introduced in R2025a.