Dual band elastomer absorber
Between these 2 resonant frequencies, reflectivity remains typically below -10dB.The nitrile matrix is a very durable material. It has good outdoor weathering characteristics, good resistance to moisture and hydraulic fluids and has proven excellent performance in naval applications. Water and salt water immersion tests showed after 1 month immersion a weight increase of only 0.5 - 0.7 %. No influence on reflectivity was noticed.
RFSS Salisbury Screens
Low frequency range cavity resonance elastomer absorber
Construction consists of a conductive coating ""lossy"" fabric, separated from a conductive ground plane by a low dielectric foam core. As a tuned (narrowband) absorber, the material must have an electrical thickness of 1/4 of a wavelength at the frequency of operation. This promotes signal attenuation by both energy dissipation within the ""lossy"" fabric material, as well as cancellation of the incoming and emerging signals at the surface, where they are 180 degrees out of phase. Through accurate control of the coating process used for the ""lossy"" fabric, absorption levels of greater than 20dB are easily and consistently achieved with a 10% bandwidth at the specified operating frequency.
RFHC - Treated Honeycomb Core Absorbers
Microwave absorbing honeycomb
Laird uses either Nomex® or fiberglass honeycomb core and applies a ""lossy"" coating to it. The RF core can have a uniform coating to optimize insertion loss or a graded coating to optimize reflection loss. The cell sizes generally used are 0.125"" to 0.187"" (3,2 mm to 4,8 mm) thick with densities of 3 to 4 lb./ft3. The performance curve shows the typical performance of a 0.5"" (12,7 mm) thick core, providing good attenuation over a broad frequency range. We can optimize the performance to account for laminated skins or core and can assist in selecting the right materials to minimize performance degradation. RFHC materials are used as ""lossy"" loads in spiral antennas and high-power antenna couplers. They are used with laminated skins to manufacture radar absorbing structural (RAS) panels and components. Our engineering staff can design a material that meets your special requirements.
Microwave Absorbing Textile Covers
Microwave Absorbing Textile Covers
Many of these products are based upon Laird RFRET foam material. RFRET is open-celled lightweight foam, which is flexible and provides excellent broadband microwave absorption. The absorber can be sewn or RF welded into different textile materials. The textile cover is chosen based upon the environmental properties desired. Vinyl, neoprene, silicone and Hypalon® are commonly used materials. Reinforcements include nylon, fiberglass, polyester and Kevlar®. A variety of attachment schemes can be used including Velcro®, zippers, buckles, tie downs and other standard attachments. Camouflage materials can also be used to provide both RF and visual protection. The foam works equally well at millimeter wave frequencies. Laird is working with other companies to provide infrared protection and integrate conductive materials into fabric coatings. A variety of conductive materials are available including Flectron nickel/copper coated fabric, aluminized glass mat, lightweight scrims and wire screens.
RFFOAM - Flexible and Structural Microwave Absorbing Foam
Shapeable free space absorber foam
The product comes in custom shapes and sizes and provides excellent broadband microwave absorption along with light weight. It is an excellent option for inside of radomes, antenna pattern improvement, and other applications in enclosed areas. For outdoor applications the material can be filled with a closed cell rigid urethane foam to create a broadband structural foam. Nominal density of the product is 12-15 pounds per cubic foot and in thicknesses from25"" to 2"". The materials can be molded to shape, machined or bonded into complex covers and components. If skins are applied, rigid lightweight structural panels are formed. Laird has developed new types of foam, including syntactic foam and phenolic foams
Custom Molded Elastomeric Covers
Tuned free space elastomer absorber
Specific elastomers can be chosen for specific environments or applications. Elastomers process by Laird for outdoor use include nitrile, neoprene, natural rubber, urethanes, silicones, fluorosilicones, and fluoroelastomers (Viton®). Fluorosilicones and fluoroelastomers provide good fuel resistance, chemical resistance and high temperature capabilities. Urethanes and nitriles offer fuel resistance with good toughness and abrasion resistance.