In most companies, RF design has been something that happened in a different lab, or even a different location, by some engineers doing some rather peculiar circuit design. Tools have developed over time that have made the job of RF design and simulation much more simple and repeatable. But the industry has become much more complex with the emergence of "system" boards that contain a mixture of RF, analog, and digital. The analog and digital sections of the board have typically been designed with a PCB design solution, while the RF sections have been designed with specialized RF tools.
What has been absent is a way to transfer the RF circuit schematic and shapes, whose parameters must be untouched when transferred from the RF design and simulation tools to the PCB design tools—and back again—to handle the inevitable design tweaking.
Now, two leaders in their respective fields have developed a link between their tools that allows that uninterrupted and unmodified parametric data to be shared, and constantly maintained, between the two systems. Agilent and Mentor Graphics have teamed up Agilent's RF design and simulation solution, the ADS, with Mentor Graphics' PCB design tools (Expedition Enterprise and Board Station XE) to make RF design-to-PCB almost seamless.
A typical RF design would begin by entering the schematic in the ADS environment and creating a first pass at the RF circuit layouts. The library system, maintained in both environments, allows the ADS to use component data or real-world measurements to simulate the design. Once the working design has been successfully simulated, it is transferred to the Mentor Graphics system and merged into the rest of the PCB design.
Now, in the context of the rest of the PCB, designers typically must modify the RF circuits to fit and connect to the rest of the system design. Using the RF design capabilities in Mentor, modifications can be made to the RF circuitry. Using the dynamic link to the ADS system, the design on the actual PCB layout can again be simulated and perfected.
Once simulation shows that the product is viable and manufacturable, the physical board can be produced and tested. In the past, this moving of the design between the RF and the PCB design environments required a great deal of manual intervention and was susceptible to errors. This new system eliminates manual errors and allows significantly better simulation and PCB design within RF's special requirements.
