Electrical arcing can cause any number of issues in a circuit that lead to unreliable operation. Without effective snubbing, arcing is associated with early failures in relays, switch contacts and solid-state components (e.g., SCRs and TRIACs). 

When it comes to aerospace and defense applications, every single component plays a role in the success and longevity of the system. Capacitors are vital in flight control systems, radar systems, signal intelligence equipment and more. They support functions across guidance and control systems, electronic warfare (EW) and power supply units. To best support these development projects, Knowles sought MIL-PRF-55681 qualification for ten capacitor styles we manufacture and test in the United States. With this qualification, you can be assured that you’re using robust and dependable ceramic capacitors in your mission-critical systems. 

This is the second installment in our RF Components for Radar series. In the first installment, we provided an overview of the key functional units in radar, including duplexing, filtering, power amplification, waveform generation, low-noise amplification (LNA), receiving and analog-to-digital conversion (ADC). Here, we’ll focus on duplexing.  

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. 

To protect people and critical equipment, military-grade electronic devices must be designed to function reliably while operating in incredibly harsh environments. Therefore, instead of continuing to use traditional silicon semiconductors, in recent years, electronic device designers have started to use wide band-gap (WBG) materials such as silicon carbide (SiC) to develop the semiconductors required for military device power supplies. In general, WBG materials can operate at much higher voltages, have better thermal characteristics, and can perform switching at much higher frequencies. Therefore, SiC-based semiconductors provide superior performance compared to silicon, including higher power efficiency, higher switching frequency, and higher temperature resistance as shown in Figure 1.

From military aircraft to electronic warfare defense systems, aerospace and defense applications are placing new demands on their power electronics. Defense electronics systems must function reliably for their lifetime while operating at higher voltages and wider temperature ranges, and all while becoming smaller, lighter, and consuming less power.

As countries around the world continue to work on more sophisticated ways to conduct military missions – including weaponry that can reach intended targets quicker with even greater accuracy while remaining virtually undetectable – aerospace and defense companies are pushing the missile speed boundaries. Military aircraft and weaponry today are capable of traveling at supersonic speeds and are even entering hypersonic speed territory. 

After decades of viewing MIL-SPECs as the gold standard for qualifying and screening parts for viability in space, NASA has recently changed course, and is adopting commercial-off-the-shelf (COTS) parts as an option for a variety of space applications. Burgeoning changes in industry trends, a drive to remain competitive, and the desire to guide budget-constrained missions pushed the organization to commission a NASA Engineering and Safety Center (NESC) study to evaluate the reliability of COTS parts. Upon completion of the study, NASA aims to create a consistent set of requirements at the agency level to minimize risk and impact of part selection/usage on the performance of NASA spaceflight technology.

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.