AWR recently published a white paper about the benefits of co-simulation. The title of the white paper is: An Electrical-Thermal MMIC Design Flow. The technical paper uses an actual design example to discuss the effectiveness of co-simulation between AWR’s Microwave Office high-frequency design software and CapeSym’s SYMMIC thermal analysis tool. An X-band RF power amplifier/low-noise amplifier MMIC for a transceiver application was designed in Microwave Office software and thermal coupling and other issues between the two circuits on the single die were quickly remedied with SYMMIC to produce optimum results.
An Electrical-Thermal MMIC Design Flow White Paper
Electronic circuit design typically begins with an assumption that the components are operating at ambient temperature. Monolithic microwave integrated Circuit (MMIC) design, in particular, violates this as the DC current flowing through the ever-shrinking devices induces heating to two, three, or even four times greater temperature (in °C). Such a large departure from assumed room temperature behavior impacts phase, gain, efficiency, noise, and intermodulation distortion. Circuit designers need tools with integrated electrical-thermal analysis to address these performance issues.
The advantages of an integrated electrical-thermal co-design flow are two-fold:
- Faster design turn-around since the MMIC designer is not dependent upon someone else to run simulations.
- Quicker ‘what-if’ electrical-thermal simulations to determine the optimum design such as the most compact active designs possible for a particular application (bias/power level/efficiency).
Through the script-based integration of SYMMIC’s thermal analysis software with the AWR design environment, practical thermal simulation is now a reality for the MMIC designer as an integrated part of an RF/microwave design flow rather than a disjointed piece of mechanical engineering software. SYMMIC’s template-based approach and sheer simulation speed combined with its scripted integration to microwave office means that more accurate device simulation is possible for electrical circuit design. Reliability can be concurrently considered with electrical performance in simulations that take no longer than a detailed electromagnetic simulation.