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.
Peter Matthews

Recent Posts
Filter Basics 9: An Introduction to Poles and Zeros
Topics: Filtering
Practical Innovation at Knowles Precision Devices
Innovating essential high technology systems with demanding specifications is always challenging; making any sort of difference requires extensive resources and deep subject matter knowledge.
But that’s what keeps it interesting.
Topics: 5G, Capacitor, News and Events, RF and Microwave, Automotive, Military and Aerospace, Medical
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 8 of this series, we dive deeper into bandwidth by looking at the history of bandwidth, how bandwidth dictates data rate, and why the type of filter required will vary depending on an application’s bandwidth requirements.
Topics: RF and Microwave, Filtering
Understanding the Nuances of Space-Level Filter Qualification and Screening
When launching expensive mission-critical equipment and people into space, there is absolutely no room for failure of any component. Therefore, if you are an RF system designer working on an aerospace application, you must be sure you are selecting high-quality, high-reliability electronic components for all your designs. But do you have a process in place for this type of component selection? At Knowles Precision Devices, we know it can be a challenging to navigate component selection for aerospace applications as there are many combinations of standards and tests that can be performed to space-qualify parts.
Topics: Military and Aerospace, High Reliability, Filtering
Looking Closer at Snubber Capacitors in Electric Vehicles
In a previous article about electric vehicles (EV), we talked about using DC link capacitors as an intermediary buffer in power converters. Today’s topic covers another useful power module component – the snubber capacitor. Snubbers are energy-absorbing circuits used to protect electronics from voltage spikes and transients caused by turning a switch from the On to Off state. Opening a switch intrinsically induces a high voltage across the device, and the snubber provides an alternate flow path for the excess energy to be absorbed by the snubber capacitor and dissipated by a resister or other load.
Topics: Capacitor, Automotive, Electric Vehicles
Filter Basics Part 7: Different Approaches to Q Factor
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.
Topics: Filtering
Filter Basics Part 6: Waveguides and Transmission Lines
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.
Microstrip Filters Deliver Small Size at High Frequencies
When selecting a filter implementation, one factor that is common across all frequencies is optimizing the size of the filter given the application and the required performance. At mmWave frequencies this can be prove to be a particularly interesting problem, given the change in the physical dimensions of the system as one moves from say 600MHz to 38GHz.
Topics: RF and Microwave
Filter Basics Part 5: Lumped Element and Distributed Element Filter Construction
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.
Medical Imaging Quality Starts by Selecting the Right Components
Healthcare professionals and patients rely on magnetic resonance imaging (MRI) technology to examine soft tissues and organs in the body to detect a variety of issues, from degenerative diseases to tumors, in a non-invasive manner. To do this, the MRI machine uses a strong magnetic field and computer-generated radio waves to produce cross-sectional images. Thus, the quality of the MRI depends on the uniformity of the magnetic field – even the smallest trace of magnetism inside an MRI scanner can disrupt the field and degrade the quality of an MRI image.