At Knowles Precision Devices, we are well known for our expertise delivering high-performance mmWave filtering options. But did you know we also excel at providing a wide variety of lower frequency filtering options using a lumped element filter construction? In this blog post, we explore the basics of lumped element filter design, general lumped element filter characteristics, and how we can push lumped element filter design limits to develop a wide variety of high-performance low-frequency filtering options.

Before jumping into a discussion on ceramic coaxial resonators, it is important to understand what a resonator is and how these electrical components work. In general, a resonator is an essential component for constructing a bandpass filter since the resonator is what will allow specified frequencies, or bands of frequencies, to pass through the filter as shown in Figure 1.

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.

The Knowles Precision Devices DLI brand of technologies has expanded to offer more products and capabilities to our customers with the acquisition of Integrated Microwave Corporation (IMC). As a result, we now offer a complete range of RF and microwave filtering solutions including custom ceramic filters, resonators, and diplexers, lumped element filters and cavity filters from the VHF to the Ka band.

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 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.

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 3 of this series, we aim to help simplify filter selection by providing an overview and reference point for five of the most commonly discussed filter technology specifications.

At this point, you’ve likely seen a slew of mainstream news articles about 5G causing safety concerns around air travel. In fact, ahead of the rollout of new 5G services from major US telecom companies including Verizon and AT&T on Jan. 19, 2022, many international airlines canceled or delayed flights to major US airports where they believed 5G signals could possibly interfere with the radar signals required to properly operate landing equipment on their planes.

At Knowles Precision Devices, we truly do love all things RF. While we are focused on using our expertise in ceramics and thin film manufacturing to innovate on our high-performance filters, our engineers also enjoy keeping up with the trends impacting the entire RF “ecosystem.” This includes dedicating time to experimenting with various open-source RF modeling and analysis tools that we think our potential non-design engineer customers might find useful. One open-source RF and microwave network analysis tool we have been playing around with lately that we feel does a particularly good job is scikit-rf, which is based on the Python programming language.