From industrial to automotive to aerospace applications, power electronics are demanding higher capacitance in smaller packages. Therefore, to meet both capacitance demands and size requirements, electronic designers simply cannot continue to add more capacitors. While capacitor stacking is an option, many stacked assemblies are still quite large and stacking often introduces new failure modes, such as piezo electric cracking (Figure 1). 

As the name implies, “thin film” is a precisely deposited layer of material used to fabricate electronic components. “Thin” can mean as little as a fraction of a nanometer thick. Circuits constructed with thin film are used in a wide range of electrical and optical applications, but they are most advantageous when high-frequency performance, tight tolerances, thermal conductivity, and long-term reliability are paramount concerns. Particularly in the high-frequency microwave space, small size, line definition, and repeatable construction offer significant performance benefits.

As interest and adoption increase in the electric vehicle (EV) arena, associated technologies are advancing quickly. Batteries are becoming more powerful and charging infrastructure is increasingly robust and efficient. With all these advancements, EV batteries are good for more than powering cars on the road.

High-speed broadband and fiber optic devices used across a variety of communication and military and aerospace applications require circuits that couple RF signals. Since this involves removing the DC component and allowing only the high-frequency AC component to pass or bypass, this can be a complicated process. The blocking capacitor needs to present a near reflectionless transition at the frequency the line is seeing and at a bandwidth that allows the entire signal to pass without degradation. 

The Knowles Precision Devices DLI brand of technologies are designed to address the complex challenges of implementing high-performance mmWave filters across the widest range of specifications. Our Microwave Product Catalog covers how to select the best catalog or custom components for your application needs, while our new Microwave Products Guide provides valuable information and recommendations for how to work with our DLI brand microwave products once you have the components in hand.

To choose the right filter for your application, you'll need to evaluate filter type, identify the specific filter technology that best suits your application, and ensure the filter meets your required specifications. This post is designed to serve as a quick reference on the common terms that are used to discuss filter type, technology, and specifications.

To start, there are four key Filter behaviors that sort them into types: Low Pass, High Pass, Band Pass, and Band Stop.

As the backbone of the X-ray machine, X-ray tubes produce the radiation that generates the electromagnetic waves known as the “X-ray.” This is done by using a high voltage to accelerate the electrons released by a hot cathode to a high velocity. Those electrons then collide with the anode, which is a metal target usually made of tungsten. This process requires an input voltage typically ranging from 180 to 480 VAC with a power supply that transforms and steps up the voltage to extremely high voltage outputs ranging from 10kV and 120kV DC. A high-level diagram of the power supply required to power the X-ray tubes is shown in Figure 1. 

According to the U.S. Bureau of Transportation Statistics, electric vehicle (EV) sales in the U.S. reached record high monthly volume in March 2021 and continued to rise, nearly doubling in 2021. This marks the sixth consecutive year of growth in electric vehicle (EV) sales and the demand is continuing to grow.

As the demand for faster communications across consumer and commercial devices continues to increase, operating frequencies of RF devices are being pushed higher and higher. This creates a number of challenges for RF device designers, as filter size must be reduced to compensate for smaller device sizes and shorter wavelengths while also maintaining high levels of performance. While surface mount technology (SMT), and in particular microstrip implementations, are an excellent option to meet these demands, it is important to note that not every SMT microstrip filter is created equal. There are a variety of choices to discuss with your filter supplier, such as substrate type, plating technology, and topology that can dramatically reduce the size and increase the performance of an SMT microstrip filter. One particular choice that Knowles Precision Devices has guided customers through for decades is the decision to use thin film for these filters.

At Knowles Precision Devices (KPD), we handle the specialty components that go in the systems that can’t quit. We have the extensive resources and subject matter knowledge to innovate around the technical and environmental challenges facing high-impact industries including military, aerospace, and beyond.