Webinar: RF board design flow examples for co-simulating active circuits

In part one of this webinar series, Keysight and Modelithics looked at the use of 3D passive vendor component models supporting highly accurate, automated 3D EM-circuit co-simulation of high-frequency RF board designs. Part two continues the exploration of RF board design flows for simulating active circuits on boards, again with accurate, parameterized Modelithics models with the appropriate versions driving simulations in Keysight EDA Advanced Design System (ADS), RFPro, and Genesys.

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Design efficiency depends on using purchasable part values in accurate simulations

In this webinar, Keysight features the use of Modelithics model libraries of vendor parts with RFPro in ADS to perform accurate EM-circuit co-simulation of RF boards, and Genesys RF circuit synthesis to automatically pick the optimal discrete purchasable vendor part values to meet performance requirements of circuits built on RF boards.

If you have ever simulated and optimized even a relatively simple circuit on an RF board design, you may have noticed that optimized component values are not available from any vendor. Designers must look up vendor parts catalogs to identify real-life purchasable components, substitute those in a circuit, re-simulate, and either live with the slightly changed results or redesign using different part values. It is a very inefficient workflow.

Genesys’ unique Vendor Parts Synthesis (VPS) utilizes the Modelithics COMPLETE Library for RF circuit synthesis. VPS starts with gradient optimization to obtain the optimal theoretical part values to meet specs, then switches to discrete grid search for the nearest purchasable real-life vendor part values and further optimizes for the best combination of upper or lower nearest discrete values to produce the best realizable results. Designers have accurate simulation results and a purchasable bill of materials ready when simulations complete, saving a tremendous amount of manual schematic adjustments.

Keysight ADS users can also employ gradient, followed by discrete optimization to obtain real-life-ready results with the Modelithics COMPLETE Library for Advanced Design System (ADS). Chris DeMartino, Applications Engineer at Modelithics, conveys a simple nonlinear component example – a model for and simulation of an Infineon BAS70 nonlinear Schottky diode in a 2.45 GHz detector circuit. Their measurement-based model of the diode delivers highly accurate simulations, as shown by the match in DC output voltage between simulated (red trace) and measured (blue Xs) results.

DeMartino provides detailed examples with Skyworks diodes and Mini-Circuits LNAs in his discussion on making EM-circuit co-simulation as easy as circuit analysis with ADS and RFPro.

Exploring what is possible with models for nonlinear components

Martin Trossing, Customer Success Manager for EDA at Keysight, builds on an example in ADS used in part one to illustrate 3D component spacing, but in this session emphasizes nonlinear behavior. His demonstration creates accurate simulations of amplifiers (LNA and PA) with EM-circuit co-simulation of the physical layout and Modelithics nonlinear component models.

Comprehensive evaluation of linear and nonlinear stability of amplifiers is easy with the Winslow stability analysis in ADS. One Winslow stability analysis with one schematic (no manual probe setups) replaces 14 separate traditional stability analyses, producing all results simultaneously.

After amplifier instabilities are detected, EM-circuit co-simulation and visualization can troubleshoot the physical locations and frequencies where undesired feedback occurs. This workflow enables amplifier designers to fix issues and eliminate multiple hardware re-spins.

Stepping through component models and RF board simulation

ADS RFPro mesh domain optimization (MDO) makes EM-circuit co-simulation of any chosen RF paths comprising layout traces and circuit models easy. It eliminates tedious traditional “cookie-cutting” of the layout for localized EM simulation, followed by manual connection of EM S-parameter ports to circuit nodes for EM-circuit analysis.

The Modelithics COMPLETE Library family contains over 28,000 passive and active components, accelerating EM-circuit co-simulations in Keysight EDA platforms and smoothly connecting designs to real-world component availability. More details and discussion follow in the RF board design flow webinar, and registration is open now:

Accelerate Your Design Flows with Highly Accurate Simulation Models