Emerson & Cuming Microwave Products offers a broad range of dielectric products used in antennas, transmission lines, cavity tuning probes, electronic modules and RF/microwave devices. Products may serve as low loss spacers, structural supports and encapsulants, thermal barriers as well as radomes. ECCOSTOCK® low loss dielectrics are available with loss tangents as low as .0001 and dielectric constants ranging from as low as 1.03 to as high as 30. Products are available as flexible and rigid foams including foam in place systems, rigid thermoset materials, composites with controlled K values as well as powders and adhesives.

Emerson & Cuming Microwave Products offers a broad range of products under the ECCOSHIELD® brand name for EMI/RFI applications. These products work by containing or excluding electromagnetic energy in RF modules and components, waveguides and structural enclosures. The ECCOSHIELD® product line offers a wide range of volume resistivities to achieve desired shielding effectiveness. Products are available as non-hardening caulking compounds, silicone or vinyl based sheets as well as conductive adhesives and coatings.

We are equipped with the technical know-how, software, and modeling capabilities to solve complex project issues

As a leader in the design and development of absorber technology materials, we understand that while material quality and design is important, being able to adequately solve and perfect challenges that arise during the design phase is key to a successful consumer experience. Our engineers thrive on innovation and welcome any request that comes their way. This is what separates us from our competitors – expert knowledge and a high quality product.

We have a full line of microwave absorber products for free space and cavity resonance applications, low loss dielectric filled polymers, custom molded elastomeric and reticulated foam, along with textile and custom composite products.

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Microwave absorbers

Microwave absorbers have been used in military and commercial applications for several decades. Traditionally they’re used for EMI reduction, antenna pattern shaping, and radar cross reduction. Recently with the rise of wireless electronics and the movement to higher frequencies, microwave absorbers or “noise suppression sheets” (NSS) are used to reduce electromagnetic interference (EMI) inside of the wireless electronics assemblies. Two types of NSS are used for these types of applications:

MAGNETIC ABSORBERS

These are thin (0.1 to 3 mm) polymeric materials filled with magnetic particles. These materials have both high permeability (magnetic loss properties) and high permittivity (dielectric loss properties). This combination of properties makes these materials extremely effective in eliminating high frequency EMI. Laird Technologies has two product types that are used for commercial applications:

FOAM ABSORBERS

These absorbers are based upon open celled foam permeated with a carbon coating. The carbon coating makes the resultant product lossy at microwave frequencies, acting like a free space resistor to incoming electromagnetic energy. These foam products range from 3.2 mm to 6.4 mm for internal cavity applications and can be several centimetres thick for outdoor applications. Two main product types are offered by Laird Technologies

Figure 1

ABSORBER APPLICATIONS

Electronics operating at high frequencies can have problems with emission of high frequency noise. Once put inside an enclosure, the energy will add in phase at certain frequencies to cause resonances, which will hinder the performance of the device. A good example of this phenomenon is seen above in Figure 1. The amplifier was measured in the condition shown and subsequently remeasured inside of its enclosure. When put inside the enclosure the performance was severely degraded due to cavity resonances inside of the enclosure. The measured data is shown in Figure 2.

Figure 2