Quality factor, or Q factor, is a common shorthand figure of merit (FOM) for RF filters. It’s typically expressed as the ratio of stored versus lost energy per oscillation cycle. Steepness of skirts, selectivity, and insertion loss are all specifications that can be described in terms of Q factor. While this FOM feels ubiquitous in RF, truly understanding how Q factor is determined and how it relates to other specifications is a complex endeavor because it’s contextual.
Topics: RF and Microwave
There are hundreds of filter applications operating across a wide range of frequencies, which presents a challenge for filter designers since most filter designs don't inherently operate across these wide ranges. Size, weight, power, and cost (SWaP-C) are also important considerations, so simply adding more filters to address different frequency ranges is not an attractive solution. There is, however, an alternative way of designing filters: combining filter technologies to meet the specific frequency, bandwidth, and size requirements of your application.
Passive gain equalizers are designed to rectify or flatten the frequency response of an RF amplifier. RF amplifiers are known to cause a non-uniform gain over the operational bandwidth of a device, which results in distortion and other unwanted effects. Equalizers generate a counter-gain profile to offset that uneven response. Pairing equalizers and amplifiers is critical in applications like broadband systems where consistent performance over a wide frequency range enhances signal fidelity and system performance.
Topics: RF and Microwave
Bias filter networks and self-bias networks are two types of biasing components developed by Knowles Precision Devices for use in high-frequency microwave and RF applications.
MRI systems are so robust and require so much infrastructure that they need their own dedicated room—until recently.
A portable magnetic resonance imaging (MRI) system, or point of care (POC) MRI machine, is a compact, traveling device that’s designed for patient imaging outside of the traditional MRI suite (e.g., emergency rooms, ambulances, rural clinics, field hospitals, etc.)
Radio frequency (RF) power dividers are designed to split an incoming signal into multiple outputs such that there’s a portion of the original signal’s power in each output. Given their critical function, power dividers play a particularly important role in antenna systems, telecommunications, and signal processing.
Defense applications tend to operate at high voltages and wide temperature ranges. They require components with increased efficiency, reduced size, and high power density. Because a wideband gap (WBG) semiconductor embodies these characteristics, defense and aerospace systems are increasingly using Gallium Nitride (GaN) for power conversion.
At a foundational level, the ability to store electric charge and more easily pass higher-frequency AC currents are two of the most identifiable properties of capacitors. However, at very high frequencies, the ideal behavior of a capacitor can be compromised. In those situations, the parasitic, resistive and inductive components of a capacitor have an outsized influence on its behavior.
Safety capacitors are designed to mitigate the effects of transient voltages and interference in electrical and electronic circuits, especially high-voltage applications, ensuring their safe operation. Even everyday devices need safety capacitors: modems and other telecoms equipment, AC-DC power supplies, power distribution switchgear, and electric vehicles (EVs) and other automotive applications.
In power electronics, the DC link refers to the section that connects the input and output sides of the power conversion system (Figure 1). The primary function of the DC link is to store energy during the times when the input power is higher than the output power and release energy when the output power demand exceeds the input power. The DC link should include a capacitor that servers as a supporting filter to act as a buffer, minimize voltage ripples, and smooth and stabilize the power flow between various components such as rectifiers, inverters, and other converters in the power system.