To help customers with filter selection, we generally provide a lot of information on what our filters can do. But in this new Filter Basics Series, we are taking a step back to cover some background information on how filters do what they do. Regardless of the technology behind the filter, there are several key concepts that all filters share that we will dive into throughout this series. By providing this detailed fundamental filter information, we hope to help you simplify your future filtering decisions. 

Part 6 expands on part 5 by covering more details on waveguides and transmission lines, including the different types of electromagnetic modes supported by each.

If you’re attending the 2022 International Microwave Symposium (IMS) June 19 – 24 at the Colorado Convention Center in Denver, you won’t want to miss the exciting information the team at Knowles Precision Devices has to share!

To ensure the efficiency and reliability of high-power wireless charging applications such as electric vehicle charging stations, wireless power transfer circuits need stable, high-capacitance, high-voltage capacitors to serve as the tank capacitor in the LC resonant circuit. Multi-layer ceramic capacitors (MLCCs) are increasingly being used in these applications due to their volumetric efficiency and cost-effective mounting techniques, but there are a number of design challenges that need to be addressed.

DC link capacitors are commonly used in power converters as an intermediary buffer between an input source to an output load that have different instantaneous power, voltages, and frequencies. In electric vehicle (EV) applications, DC link capacitors help offset the effects of inductance in inverters, motor controllers, and battery systems. They also serve as filters that protect EV subsystems from voltage spikes, surges, and electromagnetic interference (EMI).

Since a lot of electronic component manufacturers are now focusing production efforts on high-volume commodity applications, as their specialty component production equipment ages, many companies are electing to divest in this type of production. One component that we’ve seen fall into this category in recent years is the surface-mount electromagnetic interference (EMI) filter. These three-terminal chips use conventional multilayer ceramic capacitor (MLCC) manufacturing techniques to form a filter that has a short circuit end-to-end and has a capacitance between the end terminals and the side (ground) terminals. 

To help customers with filter selection, we generally provide a lot of information on what our filters can do. But in this new Filter Basics Series, we are taking a step back to cover some background information on how filters do what they do. Regardless of the technology behind the filter, there are several key concepts that all filters share that we will dive into throughout this series. By providing this detailed fundamental filter information, we hope to help you simplify your future filtering decisions.

Part 5 dives into more detail on lumped element and distributed element filter construction techniques and when each option is most appropriate to use based on your application.

Today, most converter circuits now include semiconductors and switches made of silicon carbide (SiC) instead of plain old silicon (Si). This is because when silicon and carbon are combined, the resulting material, SiC, has excellent mechanical, chemical, and thermal properties. Therefore, SiC-based converters can handle voltages up to 10 times greater than converters using just Si while also offering lower losses. These characteristics make these converters an excellent option for applications such as power electronics, industrial devices, and electric vehicle (EV) charging stations. In this post, we dive into the advantages of using snubber circuits to protect SiC-based converters and discuss how to further increase these efficiencies by focusing on capacitor selection.

To help customers with filter selection, we generally provide a lot of information on what our filters can do. But in this new Filter Basics Series, we are taking a step back to cover some background information on how filters do what they do. Regardless of the technology behind the filter, there are several key concepts that all filters share that we will dive into throughout this series. By providing this detailed fundamental filter information, we hope to help you simplify your future filtering decisions.

In part 4 of this series, we provide overviews of the main filter types and key filter technologies available today.

RF circuits for applications in the mmWave range (30 to 300 GHz) require high-performance filtering to meet the high-data, high-speed functionality that operating at these higher frequencies promises. However, filters for devices operating in the mmWave range will not function optimally if your printed circuit board (PCB) is not configured appropriately. For this reason, RF design engineers need to make a number of critical PCB design decisions that range from selecting the right materials to developing a board configuration that will limit common issues such as spurious-wave-mode propagation, conductor and radiation losses, unwanted resonance, and dispersion.

If you’re a long-time reader of our blog, you know that we typically dedicate our blog content to sharing our engineering team’s in-depth expertise and insights on the trends and technologies impacting the industries and applications we serve. We tend to be so focused on the exciting things we are working on to drive innovation in capacitor and RF filtering applications that we don’t share much about how we got to where we are now. But, as you can imagine, getting to the point we are at now with our world-class engineering and manufacturing teams, did not happen by accident.