Electronic-design-automation (EDA) tools save time and design costs while allowing engineers to focus on making products more competitive. To keep delivering on such promises, however, EDA tools must be regularly updated. For example, Agilent Technologies' EEsof EDA division recently released the 2006A version of its Advanced Design System (ADS). This software update connects products from the company's Eagleware acquisition with the mainstream ADS user base. Essentially, ADS 2006A now offers RF architecture tools that guide the selection of frequencies, a unique simulation engine for RF block diagrams, and several synthesis modules.

The three new modules are the WhatIF frequency planner, Spectrasys spectral domain simulator, and eight synthesis modules. WhatIF is a graphical tool. It helps RF architects quickly choose frequencies and up/down-conversion architectures that minimize in-band spurious frequencies. In the past, architects struggled to accomplish this task with spreadsheets and homemade tools. This tool graphically simplifies the process while connecting frequency planning to the mainstream design flow.

Spectrasys is a simulation engine for RF block diagrams. Unlike spreadsheets and simple cascaded-chain tools, Spectrasys allows for mismatch, frequencydependence, harmonics, intermodulation frequencies, and noise and signal bandwidths to propagate in both directions in a block diagram. It keeps track of each spectral product and noise contributor throughout the system as a separate term. This feature, called Spectral Propagation and Root Cause Analysis (SPARC), simplifies the troubleshooting of RF systems (see figure).

In addition, Spectrasys displays RF budget results without needing to resimulate. Unlike spreadsheets or other simulators, which are not optimized for the task, Spectrasys allows the troubleshooting of fundamental architectural flaws in seconds because of its interactive, graphical nature.

After a working RF block diagram has been established, the user synthesizes circuits and filters using a collection of synthesis modules. The entire workspace can then be transferred live to Agilent's ADS software. In ADS, the designer can use a myriad of other circuit, electromagnetic (EM), system, and physical design tools to complete the RF design and verify that it will be manufacturable and operate under realistic signal and environmental conditions.

This new toolset allows the same block diagram to be reused as it transfers from WhatIF to Spectrasys, through Synthesis, to ADS circuit design, EM, and finally high-level system design and links to test equipment. In addition, ADS 2006A now embeds hyperlinks in the simulators and documentation, allowing ADS users to query the Knowledge Center database directly from the ADS graphical user interface.Agilent Technologies, Inc., 5301 Stevens Creek Blvd., Santa Clara, CA 95051; Internet: http://eesof.tm.agilent.com/.