• Interactive, live multiple plotting system
• 16-times increase in spectral resolution
• Direct setting of C/No, Eb/No, C/N & other noise
• Tight integration with schematic capture
• Windows Modeling Wizard for MODGEN
• Units and automatic units conversion

Eight years after introducing the world's first PC telecom simulator, Tesoft has ported its award-winning TESLA software to Windows 3.1 and Windows 95. At a desktop price, TESLA 2.0 offers the latest Windows features such as tool and status bars, balloon and hypertext help, clipboard, color graphics, fonts and color printer support. Tesoft backs its products with a 30-day satisfaction guarantee.

TESLA lets you simulate modems, synthesizers, spread spectrum and other telecom systems at the block diagram level. It supports nonlinear, mixed analog and digital time simulation. Spectrum analysis is also included.

Simulation begins with drawing a block diagram using OrCAD Capture for Windows. (Netlist entry is also supported.) TESLA exploits the Windows environment to offer seamless integration with OrCAD Capture. For example, you can switch to Capture with one keystroke and change the diagram. When you save the change and switch back, TESLA automatically updates the system being simulated.

The Windows interface is also used to full advantage to display results graphically. After a simulation, you can plot spectra, waveforms, BER test results, eye-patterns and logic analyzer style graphs. Multiple plot windows can be open on the screen along with the OrCAD block diagram. Plot windows remain active. You can zoom-in by drawing a box with the mouse. Convenient panning and cursor readout controls are also provided. After plotting a graph that you want to keep, making a hardcopy, clipboard copy or graphic file is just a menu-click away.

The new Windows interface features are the main additions in this version of the simulator, but there have been important improvements in other areas as well. You can now set important noise parameters such as C/No, Eb/No, C/N or temperature directly. Spectrum analysis resolution has been increased by a factor of sixteen. One handy new feature lets you specify units when entering model settings. For example, the oscillator model recognizes 63 variations of units for power level. So you can enter a level as 0dBm, 1mW or .6324Vpp and all will result in the same setting. A new Modeling Wizard feature simplifies the process of adding new blocks to the simulator. You can use the feature to drop-in an equation, to add blocks from the TESLA BBS or to create their own new blocks. TESLA for Windows remains compatible with block diagrams, netlists, macros and simulations saved from previous versions.

Simulation Example

The example simulation shown in the figure is a 100kb/s FSK spread spectrum transmitter and receiver operating at 918.4MHz. The chipping rate is 1Mb/s. Multipath interference is included. Half of the bandpass spread spectrum is shown at the right. The center frequency is at the left axis, where the multipath notch suppresses the area around the carrier frequency. The de-spread half-spectrum is also shown.

Although the multipath notch has removed a large portion of the center of the signal, the carrier envelope holds up well...

...and the eye pattern shows usable data. A 100kb/s FSK simulation without spreading showed no discernible eye pattern.

The conclusion: TESLA 2.0 for Windows easily models complex transmission effects such as the ones which give spread spectrum an advantage in multipath transmission.

Requires Windows 3.1 or 95. Includes a 30-day satisfaction guarantee: full refund less shipping. Price: $995-1999, depending on options; Delivery: Two weeks ARO.

OrCAD is a registered trademark of OrCAD, Inc. Windows is a registered trademark of Microsoft Corporation.

The new, high-frequency version of Spectre/XL features interactive simulation for nonlinear communications circuits such as mixers and receivers, especially the frequency translation of signals and noise. Spectre/XL embeds accurate circuit simulation inside Microsoft Excel, the world's most popular analysis and presentation package. Spectre/XL's instant what-if analysis gives RF and microwave designers a powerful tool for developing, evaluating and optimizing high-frequency circuits.

A demonstration version of Avista Spectre/XL version 1B is now available for download. Editor's Note: This is no longer available as of 3/11/03. It includes 7 demonstration circuits that illustrate many of the design features of Avista Spectre/XL. The demonstration version lets you change the values of components and run any analyses you choose, but you cannot create new circuits.

You must have a copy of Microsoft Excel 7.0 for Windows 95 or Microsoft Excel 5.0 for Windows, to use the demonstration software.

To install the demo software, you run the .EXE file at a DOS prompt, not by launching directly from Windows. After you run the .EXE file list the contents of your directory. You should see the file readme.txt for Excel 7.0 installation or the file readme.txt for Excel 5.0 installation. It contains instructions on how to install the software.

To start the download of the Avista Spectre/XL Demonstration package for Microsoft Excel 7.0, click on dspxl1b7.exe. To download the Demonstration package for Microsoft Excel 5.0 click on dspxl1b5.exe. Each file is a self-exploding executable with a size of 2.0 Mbytes and 3.0 Mbytes respectively. Each package includes the Demonstration User's Guide in Microsoft Word 6.0 format.

To download a copy of the Avista Spectre/XL Demonstration User's Guide, click on dusrguid.exe. The file is a self-exploding executable in Microsoft Word 6.0 format and its size is about 600 Kbytes compressed. To download the User's Guide in Encapsulated Postscript format, click on dspxleps.Z. The file size is 420 Kbytes compressed and was produced by the UNIX compress utility.

Over the past 12 years, Interactive Image Technologies has earned a reputation for high-quality, innovative software. And since its release in 1988, Electronics Workbench has gained worldwide acclaim. With over 20,000 customers, Electronics Workbench Version 3 led the way as the most intuitive simulation tool available. Now with Version 4.1, Electronics Workbench is the affordable mixed-signal simulator.