TmlExpert – Fast and Accurate TML Modeling and Simulation

Overview

Accurate transmission line modeling is essential for high-speed PCB system. The requirement can be very different ranging from a simple 2D RLGC simulation to a complicated 3D simulation. TmlExpert is built with the consideration of all the different simulation scenarios. It has three solver technologies including 2D RLGC, 2.5D MoM and 3D FEM to achieve the best accuracy and convenience. The 2D RLGC solver offers a quick way to check the transmission line properties such as RLGC per unit length (p.u.l.), impedance and attenuation for single-ended or differential microstrip and stripline. The 2.5D MoM solver can efficiently simulate tabbed routing and serpentine lines. For the transmission lines with 3D features such as those on a hatched ground plane and fiber weave pattern, the 3D FEM solver gives the most accurate modeling and simulation. All the transmission line types in TmlExpert are parameterized with built-in templates, which further enhances the transmission line exploration for SI engineers.

HighLights
  1. Accurate transmission line modeling is essential for high speed PCB system. The requirement can be very different ranging from a simple 2D RLGC simulation to a complicated 3D simulation.
  2. TmlExpert is built with the consideration of all the different simulation scenarios.
  3. TmlExpert has three solver technologies including 2D RLGC, 2.5D MoM and 3D FEM to achieve the best accuracy and convenience.
  4. TmlExpert has various templates for transmission-line structures including hatched ground plane and fiber weave
  5. TmlExpert can help design and exploration of advanced transmission lines
Main Feautres

2D Simulation with RLGC Solver

Plenty of TML's suitable for 2D analysis 2D FEM solver with MOR technique supports

  • Causal dielectric model
  • Conductor rough surface model
  • Conductor skin-effect model

Input

  • Intuitive GUI
  • Easy parametric setup

Output

  • RLGC, impedance, attenuation, delay, skew
  • S-parameter for a give length
  • Auto plot template result
  • Export parametric variables to HFSS

2.5D MOM Analysis

When 2.5D discontinuities exist in a TML, MOM solver is used

Tabbed routing is used in

  • pin field to help manage the impedance in this area to match the impedance to the rest of the transmission line on all routing layers.
  • open field to help compress routing while improving noise on external layers.

Serpentine is used to match delays within a pair or between two pairs

3D FEM Analysis of Fiber Weave Structures

Accurate fiber weave modeling can help to

  • Assess the effect of fiber weave on skew and loss in transmission in different direction.
  • Characterize skew due to various fiber weave patterns in PCB laminates.
  • Investigate possible techniques to reduce fiber weave effect, such as zigzag-style routing
  • Balance the trade-off by applying techniques with different trace routing direction or different fiber weave patterns in PCB laminates.

Modeling challenges

  • It is three dimensional and difficult to create model
  • It is computationally intensive to simulate

3D FEM Analysis of Hatched Ground Planes

  • Microstrip and stripline
  • Option to add EMI shielding layer
  • Edit hatch style
  • Orient trace in any angle
  • Solve the structure accurately and efficiently using 3D FEM
  • Export to HFSS

3D FEM Analysis of Grounded CPW

  • Create grounding vias in no time
  • Solve the structure accurately and efficiently using 3D FEM
  • Export to HFSS

Resource Center