A Look Inside RF Design

RF EDA continues pushing the boundaries for today’s complex system designs. Connected workflows are creating shift left opportunities for engineering in virtual space. RF and microwave architects and designers can accelerate design and verification with powerful electromagnetic (EM) modeling and simulation technology. In the webinar for the 2023 launch of PathWave Advanced Design System (ADS), Keysight highlights a half dozen areas of improvements for ADS users. Before jumping to this informative session featuring slides interspersed with video segments, let’s look at some of the reasoning behind the PathWave ADS 2023 improvements.

End-to-end workflows smooth out friction

The most expensive operation in EDA is converting data from one format to another. In the past, RF EDA has been prone to data format discontinuities between layout, modeling, simulation, and physical measurements. Conversions add time, introduce the opportunity for errors, and add friction to the design workflow. Too much friction leading up to simulations tempts designers to reduce simulation efforts, stifling exploration and increasing the chance for flaws to leak into physical prototypes. Design complexity worsens this friction.

So, it’s no surprise that much of the PathWave ADS 2023 development effort focuses on smoothing out friction in the connected workflow. Many of these ideas come directly from ADS user input. An example is personalization tweaks in the data display to make items easier to see. Another is in a Broadcom guest video segment explaining how VS-Code helps streamline data conversion. There are also improvements in layout visualization: handling stacked vias and ground planes, and layout versus layout comparisons – including component views.

Layout vs. layout comparison in PathWave ADS highlighting a resistor value change.

EM-circuit co-simulation with push-button ease

Analog and digital designers have enjoyed push-button circuit simulation capability in EDA tools for quite some time. RF designs present a different problem. Accurate simulations start with high fidelity EM behavioral modeling, but more complex models drive simulation times higher. There’s also a need for multi-domain simulation using authentic modulated signals, with feedback from physical measurements. And there’s a need for dynamic electro-thermal simulation for capturing effects like self-heating and sun loading.

PathWave ADS 2023 targets all these needs – one of the video segments shows how modulated signals factor into understanding system performance metrics like error vector magnitude (EVM). By adding Keysight RFPro to PathWave ADS, EM-circuit co-simulation becomes as intuitive as circuit simulation by itself. A video segment shows displaying an EM mesh in a design layout, performing nested sweeps with parallel simulation, and seeing how process parameters affect outcomes. All this happens without users manually converting layouts or defining parameter stack-ups.

S-parameter sweep results on a multi-layer 3D structure in PathWave RFPro.

Interoperability gives designers more capability

There are two big hurdles for RF EDA interoperability: reading common data formats and connecting workflows with tools of choice from different vendors. Behind the scenes, Keysight is part of the Silicon Integration Initiative, or Si2, and its OpenAccess Coalition. Tools including PathWave ADS and PathWave RFPro can share design data from an OpenAccess database.

By unbundling PathWave RFPro, Keysight opens the door to work with RF designers who have layout environments such as Cadence Virtuoso and Synopsys Custom Compiler. An example is the recent announcement where RFPro and Synopsys Custom Compiler support EM simulation in TSMC’s N6RF design reference flow. There’s also a video segment on using RFPro with Synopsys Customer Compiler for a low-noise amplifier designed in GlobalFoundries FDX22.

With that background, both current PathWave ADS users and RF designers using other layout environments should enjoy the PathWave ADS 2023 launch webinar. There are also many other resources attached to the webinar video page for designers to see the range of capability PathWave ADS and PathWave RFPro provide.

Webinar: PathWave ADS 2023 for RF & Microwave Design