Harmonic Analysis in EMC - Developing a Software Tool for Frequency Spectrum Analysis

Abstract

EMC is crucial when it comes to designing modern electronic systems, ensuring their functionality, reliability, and regulatory compliance amidst the ever-expanding electromagnetic landscape. This master's thesis delves into the domain of EMC by investigating the possibility of developing a Python-based proof-of-concept tool. The software tool is designed to analyze frequency spectra acquired from radiated emission measurements. Its objective is to pinpoint fundamental frequencies through harmonic analysis, thereby facilitating the identification of operational frequencies from which disturbances originate. The software tool successfully identifies multiple fundamental frequencies, which was confirmed through analysis of schematics and electronic measurements. However, integer multiples of these fundamental frequencies are also falsely presented to the user, a shortfall that seems difficult to circumvent. This report presents an approach to maximizing the utility of the software tool, covering its development process, functionality, and compromises made in detail.

Popular Abstract

Automated Harmonic Analysis for Efficient EMC Troubleshooting

Imagine stepping into a room filled with people chattering. You see your best friend standing amidst the crowd and make your way over. As the two of you are speaking, you occasionally struggle to hear what your friend is saying. Sometimes the noise from the crowd is so loud that you have a hard time even hearing yourself think.

Replace your friend with a pair of wireless headphones and yourself with a laptop. Rather than communicating via sound waves at around 120 Hz, you are now communicating via electromagnetic waves at 2.4 GHz through a technology commonly known as Bluetooth. Instead of a crowd of people, you have a room filled with other peoples' computers, cellphones, and other various electronic devices. Just like when you have a hard time hearing your friend over the crowd of chatter, the laptop can have a hard time communicating with the headphones due to other devices emitting electromagnetic waves that interfere with the Bluetooth signal. Similar to when you have a hard time hearing yourself think because of the noise, imagine that the laptop screen starts to flicker because someone turned on a television in a nearby room.

Now imagine that you can hear two people talking extra loud in the crowd: their conversation disrupting the surroundings because of their high volume. You find this particular conversation extra disturbing because of the high volume, and you are unable to locate where this conversation is taking place because of the crowd. If only there was a way to know where those noisy individuals were so you could tell them to keep the volume down.

Electromagnetic interference (EMI) is the case when electronic devices emit unacceptable levels of electromagnetic radiation, we can consider them as “talking too loud” on the electromagnetic spectrum. When a device does not emit radiation that is deemed disturbing to its electromagnetic environment, electromagnetic compatibility (EMC) is achieved. Engineers go to great lengths to make sure that devices are within EMC standards. The process of achieving EMC can be an arduous affair, especially if the problematic device is complex with several printed circuit board assemblies (PCBAs). Just as you may struggle to locate particularly noisy individuals, engineers can encounter difficulties pinpointing the source of electromagnetic noise within electronic devices.

That is where this thesis project comes in. Many complex electronic devices have systems that operate on high-frequency analog and digital signals. These signals, along with their harmonics, can be radiated from the device. If fundamental frequencies can be determined by analyzing the harmonics, the emissions' origin can be pinpointed, and necessary measures can be implemented to minimize the issues. Similarly, you would be able to find the noisiest people in the room and ask them to lower their volume.

This thesis aims to explore the possibility of creating a software tool that is capable of analyzing frequency spectra from EMC measurements to determine fundamental frequencies based on harmonic analysis. The idea is that, by automating a part of the troubleshooting process, the procedure of achieving EMC will be less time-consuming and more efficient. Ultimately, this will lead to shorter time-to-market for products and greater cost efficiency for the company. This is achieved through saved man-hours and the ability to conduct more tests in-house, rather than at expensive testing sites.

• author: Hansson, Albin and Grosshög, Erik
• supervisor: Johan Gran; Johan Nilsson; Isak Stjernrup; Emil Jönsson
• organization: Department of Biomedical Engineering
• alternative title: Övertonsanalys inom EMC - Utveckling av ett mjukvaruverktyg för frekvensspektrumanalys
• course: BMEM05 20241
• year: 2024
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: EMC, Harmonics, Frequency Spectrum, Software tool, EMI
• language: English
• additional info: 2024-09
• id: 9158544
• date added to LUP: 2024-06-18 15:17:37
• date last changed: 2024-06-18 15:17:37