Computer-aided-engineering (CAE) software for high-frequency design and analysis comes in many shapes and sizes. What started as a handful-of tools running on time-share computers a few decades earlier has blossomed into a market populated by numerous software developers and extensive product lines. The software products are as varied from freeware tools to perform simple calculations and filter analysis to full-fledged frameworks under which other programs operate. What follows is a brief update on recent developments in RF/microwave CAE software companies and their tools. For more information on CAE companies mentioned (or not mentioned) here, please consult with the Microwaves & RF Product Data Directory, available online at www.mwrfpdd.com.

At one time, SPICE-based software was a CAE tool of choice for many high-frequency designers, although such dedicated programs have largely been replaced by suites of modern tools operating under a common framework or graphical user interface (GUI). Still, for engineers familiar with SPICE, Beige Bag Software (www.beigebag.com) offers their own flavor of the software in the form of B2 Spice. Currently available in Version 5.1.2a, this latest edition features an upgraded user interface. It can perform mixed-mode simulations and automatically convert netlists to schematic diagrams. It includes virtual instruments, such as distortion meters, wattmeters, and oscilloscopes, which allow users to include simulated measurements in their analysis. DesignSoft (www.tina.com) offers their TINA Design Suite, an affordable but fully functional software package for analyzing analog, digital, and mixed-signal electronic circuits and their printedcircuit-board (PCB) layouts.

EM Wonder (www.emwonder.com) and their EMtoSPICE program allows SPICE simulation in both the frequency and time domains using S-parameter data. It accepts S-parameters in Touchstone or Raw Data formats and generates accurate SPICE models over broad frequency ranges.

For amplifier designers, AMPSA (www.ampsa.com) and their Mosaic Impedance-Matching Wizard software provides the capability to design highquality impedance matching networks with microstrip. The latest generation of the software, Version 8.8, can automatically transform the electrical description of a synthesized circuit into microstrip or stripline form, with automatic compensation for discontinuity effects. Viahole terminations can be added for shorted stubs and commands are provided to curve or meander lines. It can import data from Touchstone files and can translate its own files into Super-Compact or Touchstone nodal-analysis circuit files. It can also create Microwave Office schematic scripts for Applied Wave Research's (www.mwoffice.com) framework, Microwave Office, from AMPSA's MultiMatch circuits.

For filter designers, Filter Solutions (www.filter-solutions.com) offers three different filter programs based on a customer's ability to pay or not pay, since one of the programs is freeware. The company's Filter Solutions, Filter Light, and Filter Free are comprehensive PC Windows based filter synthesis and analysis software packages for active, passive, transmission line, switched capacitor, and digital filters. Filter Light is a low-cost version of Filter Solutions with reduced functionality, while Filter Free is a freeware version with minimal functionality. Visitors to the firm's website can download any of the programs, with a no charge 20-day trial period for Filter Solutions and Filter Light, and simply no charge for Filter Free.

One of the more dynamic areas in RF/microwave CAE software in recent years has been in the advancement and acceptance of electromagnetic (EM) simulation tools. One of the earliest commercial suppliers of EM simulation software, Sonnet Software (www.sonnetusa.com), offers their excellent three-dimensional (3D) planar EM simulator that is an intelligent blend of analysis power and processing speed, usually trade-offs for most EM simlators. In an area of products in which simulators are described as "two-and-one-half dimensions" (2.5D) and 3D, Sonnet Software offers a video presentation on their website that describes four different types of EM analyses and gives a commercial example for each type. The excellent video, narrated by Sonnet founder and president Jim Rautio, details the differences between different types of EM tools, including full 3D analysis tools, planar 3D tools, and planar 2.5D tools. The video provides a "dream-team" lineup of four key EM tools—HFSS from Ansoft (www.ansoft.com), CST Microwave Studio from Computer Simulation Technology (www.cst.com), Momentum from Agilent Technologies (www. agilent.com), and Sonnet from Sonnet Software (www.sonnetusa.com)—that help designers tackle almost any highfrequency EM analysis issue.

Sonnet paid tribute this month to James Clerk Maxwell, recognizing the 175th anniversary of his birth on June 13th. Celebrating with the high-frequency industry at the annual Microwave Theory & Techniques Symposium (MTT-S) in San Francisco, Rautio presented a talk on the Life of James Clerk Maxwell and "those four simple equations" that have meant so much to the field of EM analysis.

One of the leading suppliers of 3D EM software, Zeland Software (www. zeeland.com), recently announced the seamless integration of their flagship IE3D EM simulator and the Applied Wave Research (AWR) Design Environment. The integration reinforces the EM simulation capabilities of IE3D with AWR's circuit and system-level simulation tools. The IE3D engine performs in the background of the Microwave Office Design Environment as if it were a built-in EM simulation, in the manner of the EMSight simulator from Microwave Office. The IE3D program is a full-wave 3D, MoM simulator that solves for the current distribution on 3D and multilayer structures of general shape, and has been used to analyze interconnects, packages, low-temperature-cofired-ceramic (LTCC) circuits, patch antennas, and integrated circuits (ICs).