Less prototyping rounds and EMC challenges with simulation
Simulation speeds up design and helps improve the end product quality. EMC, or Electromagnetic Compatibility, is wise to be taken into account in design from the very beginning.
”In far too many projects the EMC requirements are remembered only at the very end of the development project. In the worst case, the design has to be completely restarted if the product causes radio frequency emissions more than the regulations allow, or the product does not function properly due to radio frequency interference”, warns Senior EMC Specialist Marko Luukkainen. Luukkainen, who works in Etteplan’s Jyväskylä unit, has got over 20 years of experience in RF and EMC field.
What if the EMC problem is nevertheless detected in the measurements only when the deadline is already approaching?
”There are many ways to act. Luckily, simulation helps recognize the problems and develop fixes as fast as possible. But when the fixes need to be done in a hurry, the functional quality and features of the product may have to be compromised. Also, the manufacturing costs may increase. The best results are achieved, when EMC is taken into account from the very beginning of the project”, reminds Luukkainen.
”EMC reviews and simulations are worth including to the development project from the beginning of electronics and mechanical design”, emphasizes Marko Luukkainen.
Old working methods revised
The traditional product development way of working is familiar to us all. Design, manufacture prototypes, measure, make the necessary changes and start another round. One cycle may take weeks or even months.
Some of the prototyping can often be replaced with simulation.
”Let’s plan, create a simulation model and make a computer do calculations for a day or two. Then let’s then analyse the results and make necessary corrections. This will save us huge amounts of time and unnecessary prototype rounds”, praises Luukkainen.
According to Luukkainen, simulation suits nicely for example for antenna design, for analysing EMC, RF interoperability, shielding effectiveness and radiating fields. It can also be used to review the current layout, design and mechanics.
“Also the traditional prototypes are still of course needed”, he admits.
”Avoid unnecessary pondering and many prototyping rounds. Turn to an EMC and simulation specialist as early as possible”, advises Luukkainen.
Picture - RF Immunity Simulation. The device (model) is placed in a virtual test chamber and the device is exposed to RF radiation of different frequencies from various angles. Red color represents possible high vulnerability.
Proven in practice: simulation works
”I used to doubt the possibilities of simulation. A recent project made me however change my opinion”, tells Project Manager Niko Auvinen from Etteplan’s Espoo office.
”We designed the electronics to a device operating in a demanding industrial environment. The electronics included proper EMI (Electromagnetic Interference) filtering which was carefully designed according to best practices. Yet measurements revealed problems. A mobile phone brought close caused functional errors in the device”, tells Auvinen.
There was not much time. Auvinen contacted Etteplan’s Jyväskylä office and Senior EMC Specialist Marko Luukkainen there. He inspected the device, modelled it and made the simulator do the calculations. The results calculated by the simulator correlated quite accurately with the measurements obtained with a real prototype.
Picture - The correlation between measurement and simulation. Simulation estimates the levels and frequencies of RF radiation emitted by the device.
So, the simulation model was proven valid and accurate enough for the analysis of the design. The root cause of the EMC issues was soon revealed by analysing the simulation model and correlations between simulations and test results.
This convinced the design team of the benefits of EMC simulation. From this point on simulation was used to find the best possible layout design for the areas with the immunity problems.
With the qualified help of the Jyväskylä unit the problem source was identified and the device was adjusted accordingly.
”The EMC immunity problem was repaired quickly, and the customer received a product filling all the requirements in time”, rejoices Niko Auvinen.
”This project convinced me. Simulation is a very good tool to solve EMC problems” says Auvinen. He will definitely use simulation in the upcoming projects as well.
Senior EMC Specialist