Many critical military operations around the world are increasingly relying on a variety of electronic warfare devices for a range of threat suppression, detection, and neutralization activities. This means that numerous devices operating across the RF spectrum including low-frequency devices in the VHF band and mmWave devices in the Ka band are necessary. As shown in Figure 1, when many electronic warfare devices are in use, a large number of signals are being sent and received and crossing paths. Therefore, it’s easy for any one of these devices to experience issues with interference if proper filtering techniques are not in place.

We are pleased to announce that the Knowles Corporation recently acquired Integrated Microwave Corporation (IMC), a leader in the design and manufacture of custom precision RF microwave filters and multiplexers for the aerospace, defense, and communications industries. With this acquisition, the Knowles Precision Devices Microwave group can now offer a complete range of RF and microwave filtering solutions that support applications from the VHF to the Ka band. In addition to the small, temperature-stable filters our customers have come to know us for, we can now deliver ceramic and cavity filters for lower frequency and/or higher power applications. The full range of the IMC filter technologies we now offer is shown in the graphic below.

To provide a better understanding of build-to-print in general and the breadth of our offerings, as well as how our thin-film technology can benefit your applications, we’ve put together a Build-to-Print Basics series. In this final post of our Build-to-Print Basics series, we discuss the quality standards we follow to ensure our components are qualified for military and space grade applications as well as the additional testing or spec design we can perform as needed by our customers.

As early adopters of beamforming technology in the 1960s, aerospace and defense organizations have a lot of experience using the initial large-scale active electronically scanned arrays (AESAs) for military radar tracking applications. But these arrays aren’t as convenient for some applications today as the operational frequencies of the targets of interest for many military applications are increasing. This means the wavelengths of the signals that need to be monitored are getting shorter and these radar applications need denser arrays since antenna spacing needs to be set at one half the wavelength. For example, at 25GHz, the wavelength in free space is approximately 12mm (0.47”), leading to half-wave spacing for antennas of 6mm (0.24”). Also, as arrays become denser, the new challenge for RF system designers is avoiding interference in these tighter spaces, especially when transmitting signals.

To provide a better understanding of build-to-print in general and the breadth of our offerings, as well as how our thin-film technology can benefit your applications, we’ve put together a Build-to-Print Basics series. In part 14 we discuss a range of non-standard testing services our facilities can provide when needed by our build-to-print customers.

Today, electronic warfare applications need to detect a wide variety of signals ranging from UHF communications to GPS and other data signals in the L band to high-frequency radar signals that can fall in the X, S, or K bands. Therefore, these receivers need to operate across an extremely wide range of bandwidths to pick up and understand signals anywhere from 300MHz to 20GHz and beyond. However, a basic general wideband antenna isn’t sufficient for these applications because selectivity is needed to determine what you are actually listening to. Additionally, as if the task of designing an ultra-wideband receiver with selectivity wasn’t challenging enough, RF designers are simultaneously facing pressure to reduce the size, weight, and power (SWaP) of these applications as well.

Explosives are dangerous by design. For applications involving detonation, like munition and down-hole exploration, explosives should be built to avoid unintentional or premature detonation caused by any rise in temperature or shock. These applications require a number of specialty components including capacitors that discharge high energy at temperatures up to 200°C.

To provide a better understanding of build-to-print in general and the breadth of our offerings, as well as how our thin-film technology can benefit your applications, we’ve put together a Build-to-Print Basics series. In part 13 we provide an overview of how we use our build-to-print process and thin-film expertise to develop bias networks that support the functionality of active microwave components while also minimizing the space needed in a circuit for certain components and simplifying circuit assembly.

In part 1 of this two-part guide, we talked about the trade-offs you need to make when selecting the type of capacitor that will be the best fit for your application and the basics of trimmer capacitor design including dielectric material options. This second post focuses more on the details of trimmer capacitor specs and how to determine what's right for your application.

As you already know, capacitors are essential circuit elements for storing and suppling charge on demand. For inductors and resistors, capacitors act as the building blocks of passive circuits and the supporting components for active circuits. While a wide range of fixed-value capacitors are used in most electrical circuits, it is sometimes preferable, or necessary, to use a component with a variable capacitance range.