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Impedance Matching and Transmission Lines
A matching network optimizes the transfer of power from a source to a load by maximizing the power delivered to the load while meeting other performance specifications. For small-signal RF circuits, the power delivered to the load is maximized by conjugate-matching it to the source with a ...




Circuit Sage Tools


WEB TOOLS
Matching network transformations:
Interactive impedance matching tool
Lumped BALUN tool:
This tool calculates the Ls and Cs value of the lumped balun that transform single ended impedance to differential impedance.


MATHCAD/MATLAB
Simple Mathcad high-pass matching network routine:
Simple Mathcad routine to design an LC high-pass matching network given source and load impedances
Simple Mathcad high-pass matching network routine (.pdf):
.pdf file of Mathcad high-pass LC matching routine
Comprehensive Mathcad high-pass matching network routine:
Analysis of high-pass LC network, includes S-parameters plots and Smith Chart analysis
Comprehensive Mathcad high-pass matching network routine (.pdf):
.pdf file of comprehensive Mathcad high-pass LC matching routine
Simple Mathcad low-pass matching network routine:
Simple Mathcad routine to design an LC low-pass matching network given source and load impedances
Simple Mathcad low-pass matching network routine (.pdf):
.pdf file of Mathcad low-pass LC matching routine
Comprehensive Mathcad low-pass matching network routine:
Analysis of low-pass LC network, includes S-parameters plots and Smith Chart analysis
Mathcad Smith Chart impedance matching routine:
Mathcad routine for graphical impedance matching with a Smith Chart
Mathcad Smith Chart impedance matching routine (.pdf):
.pdf of Mathcad impedance matching routine
Mathcad Smith Chart impedance matching routines:
Collection of impedance matching networks
Mathcad Smith Chart impedance matching routines (.pdf):
.pdf of impedance matching netowkr collection
Mathcad transmission line matching routine:
Mathcad routine for matching impedances using different types of transmission lines
Mathcad transmission line matching routine (.pdf):
.pdf of Mathcad transmission line routine
Mathcad broadband matching network routine #1:
Roald Maximo's routine calculates LC elements of a broadband matching network
Mathcad broadband matching network routine #2:
Roald Maximo's routine calculates LC elements of a broadband matching network
Circuit Sage's Mathcad routine for T-Lines:
Circuit Sage's Mathcad routine for T-Lines
Mathcad inductor andalysis and synthesis tool:
Mathcad inductor andalysis and synthesis tool


Online Tools


MATHCAD/MATLAB
Interactive matching spreadsheet:
5th from the top, interactive Excel tool with circuit schematics
Smith Chart for Excel:
Plotting on a Smith Chart using Excel
Professor Reinhold Ludwig's MATLAB files:
From his book RF Circuit Design. Great stuff! Click on M-files on the left frame.
Mathcad routine for spiral inductors from UNC-Charlotte:
Mathcad routine for spiral inductors from UNC-Charlotte


SOFTWARE
Lance Lascari's Smith Chart program:
Matching network and filter synthesis
ZZMatch:
LC impedance matching design and analysis, for PC's. Includes Monte Carlo. $500, free to try for 20 days
RFMatch (FREE):
Freeware uses Smith Chart to do impedance matching. Very popular!
Wmatch:
From Michael Hutt, impedance matching over a range of frequencies using cascaded LC sections
LINC2 suite:
$500, differential filter design and many other features
RF Netwok Designer:
$119, design many types of networks
TRLine (FREE):
Freeware to design transmission lines, nice.
Diplexer, PI-EL, and RevLoad:
Freeware tools from Jim Tonne to help design matching networks
Puff :
Caltech software, no longer distributed individually. It comes bundled with this book. Both book and software are very popular
Csmith from Stephan Weber:
$35, looks really nice and offers Monte Carlo analysis
Nathan Iyer's Quicksmith (FREE!):
**Very** useful software, and did I mention it's free?! Highly recommended
WinSmith 2.0:
$150, originally from Eagleware, now Agilent
Impedance matching tool (FREE):
Impedance matching tool using the Smith Chart. Free.
ATLC:
Analyzes transmission lines of arbitrary cross sections
Stripline impedance calculator:
Impedance and line width calculator, DOS
Transcalc (FREE):
TL calculator can calculate either electrical properties or physical parameters from the user inputs
TRLINE (FREE):
Great learning tool for understanding the most common TL types
Rousslan Goulouev's TL tool:
Online tool to simulate planar structures, very good
Sonnet Lite (FREE!):
Looks *nice* and the price is right!
Arpeggio (FREE):
Free full-wave EM simulator
FDTD:
Models EM wave propagation on a PCB
Indentro inductor optimization tool from Lund University (Sweden):
FREE Windows software generates outputs for both FastHenry and Cadence
Fast Field Solvers (FREE):
FastCap and FastHenry field solvers to simulate EM behavior of 3-D structures
Agilent's Momentum:
Planar EM simulator
Ansoft HFSS:
Very popular EM simulator


WEB TOOLS
Agilent's interactive impedance matching game:
Impedance matching game to get the feeling of how to design an LC network with the Smith Chart
Jim Hawking's pi network calculator:
Intuitive Java tool and downloadable application
Interactive pi network calculator:
From Green Bay Professional Packet Radio
Hao Shi's Smith Chart applet:
Allows you to view gamma or an impedance/admittance on the Smith Chart and view parameters of any other point in the chart
Wheeler Stripline Impedance Calculator:
Free online javascript-based calculator
Amanogawa's transmission line tools (FREE):
24 TL online tools in Java, very nice!
Boris Bradel's transmission line applet:
Plots waveforms and Smith Chart
PCB trace impedance calculator from U. of Missouri-Rolla:
Calculates the characteristic impedance and per-unit-length parameters of typical printed circuit board trace geometries.


Online Articles
Professor Reinhold Ludwig's course notes at WPI:
Very good reference for transmission lines and matching, 28 lectures in .pdf with plots and equations
Motorola application note on RF power matching:
Practical article on matching for power amplifiers
Broadband HF antenna matching :
By William Sabin, using ARRL Radio Designer software
Philip H. Smith: A Biography:
Very interesting biography of the Smith Chart creator
SS-Mag's Smith Chart resources page:
Software and links to other pages about the Smith Chart
How to build a Smith Chart with Mathcad:
Using Mathcad to draw Smith Charts and solve matching problems
Maxim's tutorial:
Tutorial on RF impedance matching, presents equations used to build the Smith Chart
Impedance matching class notes:
Various note sets on impedance matching. Very nice.
Modelling skin effects in SPICE:
Simulation technique to model skin effect in SPICE, verified with experiment
Time-domain model of dispersion transmission line thesis:
Master's thesis uisng APLAC software
Transmission line scaling:
How length and width of a trace affect its bandwidth
Transmission lines articles:
By Douglas Brooks
Model for shielded suspended substrate microstrip line:
Model for SS Microstrip line in APLAC
UC - San Diego notes on transmission lines:
Nice! 26 pages with equations and simulation results
Transmission lines class notes:
From University of Surrey
Microwave circuit design class notes:
Various notes sets on transmission lines and waveguides. *Nice*
Lectures on transmission lines from Keio University:
Transmission-line effects of interconnects on digital interfaces and signal integrity
Distributed Integrated Circuits for high-frequency design:
Presents an alternative methodology to design high-frequency circuits
Non-linear transmission lines for pulse-shaping in silicon:
Implements silicon NLTLs for edge-sharpening of very high frequency signals.
De-embedding techniques for measuring IC transmission lines:
De-embedding technique verified by measuring 90-nm and 130-nm CMOS microstrip lines
Transmission-Line based technique for de-embedding noise measurements:
Techniques to measure noise at very high frequencies
Microstrip impedance table from RFMD:
Characteristic impedance of strip lines based on their dimensions
RFIC Design course notes at Oregn State:
Topics include LNA's, mixers, and impedance matching
Transmission Lines presentation from U. of Puerto Rico:
Basic equations of TLs, Smith Charts, microstrip lines.
MIT's OCW courses on electromagnetism:
ECE and Physics departments courses on electromagnetism and applications, lecture notes and animations (video)
Maxim RFIC App Notes:
Various topics on RFIC's including PA's and LNA's
Citeseer:
Great reserach tool, search over 1 million articles
Modeling and screening of on-chip interconnect inducatnce thesis from Stanford:
Presents inductance-screening tool that analyzes an extracted netlist and determines which nets are sensitive to inductances (most aren't)
Near-speed-of-light on-chip interconnects thesis from Stanford:
Explores limits of propagation speeds of signals over on-chip interconnects. Presents idea of modulating a digital signal in order to take advantage of the transmission-line effects of on-chip interconnects.
Optimal termination of high-speed on-chip interconnects paper from Osaka University:
Discusses how to optimize resistive terminations of on-chip transmission lines by trading off power dissipated with maximum signal bandwidth
Modeling of copper interconnects from 1 to 110 GHz paper from NTHU in Taiwan:
Modeling of copper interconnects with and without ground shielding is presented and verified with measurements of structures in 0.13-um CMOS.
Semi-coaxial transmission lines in CMOS paper from NTHU in Taiwan:
Design and measurement of semi-coaxial lines in 0.18-micron CMOS and comparison to microstrip and CPW's implemented in the same technology.


Books
RF Circuit Design, Second Edition by Chris Boswick:
Very good RF resource. From a reviewer: "...An excellent, concise, introduction to RF circuit design. The emphasis is on the practical aspects relating to RF circuit design..."
Microwave Transistor Amplifiers: Analysis and Design by Guillermo Gonzalez:
S-parameters and matching networks followed by microwave amplifiers. Very good book.
Electromagnetic Waves and Antennas by Sophocles J. Orfanidis (FREE!):
FREE online book from Rutgers, chapters 10, 12, and 13 with great information on Smith Chart, impedance matching, and transmission lines
Digital Transmission Lines: Computer Modelling and Analysis with CD-ROM by Kenneth Granzow:
from description: "...The text's most significant feature is its method of simulating crosstalk between closely spaced traces on a circuit board and providing design tools for its control. The author explains methods that he has successfully used to simulate multi-wire transmission line signal propagation; provides explanations that enhance students' understanding of propagation and crosstalk; and uses mathematical algorithms for their numerical evaluation..."
Electromagnetics Explained by Ron Schmitt:
From an Amazon review:"...Many engineers face a large gap between the elegant simplicity of Maxwell's equations and the practical aspects of electromagnetic issues. Electromagnetics Explained by Ron Schmitt bridges that chasm..."
High Speed Digital Design: A Handbook of Black Magic by Howard Johnson:
from description: "...this comprehensive volume will help engineers who work with digital systems, shorten their product development cycles, and fix their latest high-speed design problems...."
Foundations for Microwave Engineering by Robert Collin:
Re-issue of 1992 book that is highly regarded by many
Microwave Engineering by David Pozar:
Very good reviews of this book in Amazon, relatively inexpensive copies made available by resellers
Planar Microwave Engineering by Thomas Lee:
Very good reviews, and CD-ROM includes many tools like Puff from Caltech
Electromagnetics for High-Speed Analog and Digital Communication Circuits by Ali Niknejad:
from description: "...reviews the fundamentals of electromagnetism in passive and active circuit elements, highlighting various effects and potential problems in designing a new circuit...."
Besser Associates' Applied RF Techniques I:
5-day course offered on location, $2195
Electromagnetic compatibility courses from U of Missouri-Rolla's EMC lab:
2 courses, each about 40 video-taped lectures, on EMC principles and signal integrity in high speed circuit design
RF Circuit Design: Theory & Applications by Reinhold Ludwig:
Includes MATLAB CD. Lots of stuff on matching and transmission lines
Microwave Solid State Circuit Design by I. Bahl and P. Bhartia:
From description:"...Topics covered include transmission lines and lumped elements, resonators, impedance matching networks, hybrids and couplers, filters, active and passive solid state devices, oscillators, amplifiers, detectors and mixers, microwave control circuits, frequency multipliers and dividers, computer-aided design, microwave integrated circuits, and future trends in microwave circuits. Appendixes cover S-parameters and ABCD parameters; transfer functions: Bessel, Butterworth, Chebyshev, Gaussian, etc.; nonreciprocal components, and noise..."
Microwave Filters, Impedance-Matching Networks, and Coupling Structures by G. Matthaei:
From an Amazon reviewer:"...This book is the bible of Microwave Filters, Impedance-Matching Networks and Coupling Structures. The novice can jump right in and start designing structures. The experienced engineer will find in-depth study and insight into many rf structures..."
RF Design Guide: Systems, Circuits, and Equations by P. Vizmuller:
From and Amazon reviewer:"...Not only is this book fantastic on its treatment of practical rf design, but it also has (on an included 3.5" disk) five Excel spreadsheets -- with 100's of formulas -- that make such wireless designs far easier to calculate. I strongly recommend Mr. Vizmuller's book for both wireless circuit and systems design..." Another:"...Many formulas with Excel disk to calculate. Very impressive and saves hours and hours of headaches and math. ..." One question: Does *anyone* out there still own a 3.5" disk drive?? Anyone?? A 3.5" disk holds about a minute and a half worth of 128 kbps MP3 audio, if memory serves.