## Multilayer Substrate Analysis

The CONMLS code is a modern Fortran implementation of the models discussed in [1, 2, 3, 4, 5] to simulate multilayer substrates enclosed by solid reference planes. Example screenshots of the graphical user interface are given in Figures 1 and 2.

Figure 3 illustrates the program functionality and main building blocks. An interpreter reads the input files, which are a high-level description of the structure to be simulated. These files are then decoded. A second code component gets the variables created by the interpreter and identifies the cavities and their related interconnect elements. Then, the calculator computes the parallel-plate impedance per cavity, generates or imports the transmission line models for traces, and calculates or reads the via-to-plane capacitances to approximate the near fields in the antipad region. The calculator combines the plane and trace model by applying modal decomposition, and creates the interconnection matrices for via capacitances and lumped elements. Finally, the partial results are concatenated using, for instance, segmentation techniques. Post-processing functions and utilities are available to store (e.g. as lydite- or touchstoner files [6]) and visualize the results. This version utilizes a revised CIM package [7] which allows the computation of arbitrary-shaped planes by applying the contour integral method. Another previously external algorithm for the computation of MTL systems with an hybrid 2D approach for arbitrary cross sections [7, 8] is included in the CONMLS code.

Figure 4 shows the required input files and their dependencies. The fundamental configuration is provided through the simulation setup (.sim-file). The choice of algorithms and their respective parameters is contained in this file. Moreover, models may be freely parameterized with regard to variables and parameter sweeps, all of which are to be defined in the simulation setup. Additional files such as the geometry specification are linked. Geometry definition of PCB layout, stackup, vias, and multi-conductor transmission lines (MTLs) are to be provided through .geo-files. These files may utilize physical material definitions that are located in .matr-files.

**Related Publications: **

R. Rimolo-Donadio

Development, validation, and application of semi-analytical interconnect models for efficient modeling of multilayer substrates

Ph.D. dissertation, Hamburg University of Technology, Hamburg, Germany, 2010

R. Rimolo-Donadio, X. Gu, Y. Kwark, M. Ritter, B. Archambeault, F. de Paulis, Y. Zhang, J. Fan, H.-D. Brüns, and C. Schuster

Physics-based via and trace models for efficient link simulation on multilayer structures up to 40 GHz

IEEE Transactions on Microwave Theory and Techniques, vol. 57, no. 8, pp. 2072–2083, Aug. 2009

R. Rimolo-Donadio, A. Stepan, H.-D. Brüns, J. Drewniak, and C. Schuster

Simulation of via interconnects using physics-based models and microwave network parameters

Signal Propagation on Interconnects (SPI), 12th IEEE Workshop, May 2008

T. Reuschel, S. Müller, and C. Schuster

Segmented physics-based modeling of multilayer printed circuit boards using stripline ports

IEEE Transactions on Electromagnetic Compatibility, vol. 58, no. 1, pp. 197–206, Feb. 2016

T. Reuschel, M. Kotzev, D. Dahl, and C. Schuster

Modeling of differential striplines in segmented simulation of printed circuit board links

IEEE Int. Symp. Electromagn. Compat. (EMC), Ottawa, ON, Canada, Jul. 2016

EIA/IBIS Open Forum

Touchstone(R) (.SnP) file format specification. Rev 1.1

http://vhdl.org/ibis/connector/touchstone_spec11.pdf, Mar. 2014

X. Duan, R. Rimolo-Donadio, H.-D. Brüns, and C. Schuster

A combined method for fast analysis of signal propagation, ground noise, and radiated emission of multilayer printed circuit boards

IEEE Transactions on Electromagnetic Compatibility, vol. 52, no. 2, pp. 487–495, May 2010

H. Färber

Segmentierte Modellierung gekoppelter Mehrfachstreifenleitungen auf Leiterplatten

Bachelor Thesis, TUHH, 2011

S. Müller

Including multiconductor transmission lines in a quasi-analytical model for multilayer structures

Diplomarbeit, TUHH, 2009

Please find blow:

- Download-Link (November 2017): CONMLS for Windows 64 bit computers (Demo Version)
- CONMLS manual:
**PDF**

(Source Wikipedia)

CONMLS uses the HDF5 format for storing data.