Foam Absorbers

C-RAM LF is a series of lightweight, flexible, broadband radar absorbers made from graded layers of lossy open-cell plastic foam. It is designed to provide typically 20 dB of reflectivity reduction in a frequency range dependent upon grade. The product is flexible enough to conform to moderately contoured surfaces. C-RAM LF is useful for reducing reflections in radar test ranges, inside radomes, around antennas, and for modifying antenna radiation patterns. It is also available in two weatherproof versions:

C-RAM LF-W is standard LF absorber wrapped in a thin weatherproof fabric tarp. The coating on this tarp is polychloroprene. Color is olive green. For severe weathering conditions, the product can be supplied wrapped in a white colored hypalon tarp which will withstand long term sun and rain exposure, but with a penalty of reduced reflectivity performance.

C-RAM AR is a line of reticulated foam radar absorbing sheet materials, comprised of urethane foam and a gradient lossy coating. C-RAM AR absorbs microwave energy across a wide range of frequencies. Typically the thicker the material the lower in frequency C-RAM AR will attenuate. C-RAM AR has proven to be ideal for lining shrouds of communications antennas for the suppression of sidelobes. It can also be used to cover fences to separate adjacent antennas, and shield or isolate equipment. The open-cell structure permits airflow freely through the absorber. When used outdoors, rain will also freely drain from the product. Cuming Microwave offers two types of C-RAM AR: our standard performance AR and high performance AR.

Typically the standard performance AR is suitable for most antenna shroud applications, and high performance AR is suited for applications where maximum attenuation is desired, such as RCS reduction, chamber fences, Radomes, electronic enclosures and foam through applications. If standard performance AR is suitable it will cost less than high performance AR. Reticulated foam absorbers in general are the lowest cost absorbers, including high performance AR. AR can also be supplied as an insertion loss material. On specialty applications AR has been purchased up to 3.0” thick. Consult the factory if a required thickness is not listed.

C-RAM CS and CS-HT are series of materials with controlled surface resistivity and dissipation factor. Both materials are based on a lightweight woven fiberglass cloth, which is coated with a carbon loaded coating yielding well controlled resistance and RF loss.

C-RAM CS and CS-HT are space cloth type materials exhibiting traditional woven fabric characteristics allowing air and liquids to pass through the material.

Standard C-RAM CS will tolerate continuous use through 215°F. C-RAM CS-HT is made with a binder which exhibits high thermal breakdown, thus the material will withstand continuous use through 300°F and short time exposure up to 375°F.

C-RAM CS can be provided with a conductive surface, but preferably a non-conductive outer coating is applied for protection and performance consistency. For this reason C-RAM CS is tested and controlled by its insertion loss, measured with the material at a 0° incidence angle.

Cuming Microwave offers a series of syntactic foams, both low loss dielectric, and treated lossy materials. These lightweight, high strength materials can be tailored to meet specific program requirements. Both the dielectric and lossy properties can be adjusted to meet unique project applications.

Cuming Microwave’s cyanate ester syntactic materials are available in uncured, pack-in-place, cured sheet stock and molded to shape. The Pack-In-Place has the consistency of wet sand, and is readily packed into complex shapes. The product can be purchased as a 250 oF cure or a 350oF cure material. Please contact Cuming Microwave’s Technical Staff to discuss the specifics of your application.

Low loss dielectric parameters can be adjusted with the use of metallic fillers. We can also add loss to the material with various lossy fillers.

C-RAM PIM-465 is a line of outdoor reflectivity foam sheet material, comprised of urethane foam and a lossy carbon loading. C-RAM PIM-465 absorbs RF microwave energy across 700 MHz through 3 GHz. frequencies. C-RAM PIM-465 has proven to be ideal for PIM reduction, mainly used to cover metallic surfaces. it can also be used to cover fences. The open-cell structure permits airflow freely through the absorber. When used outdoors, rain will also freely drain from the product.

C-RAM PIM-465 FR is a line of flame retardant indoor reflectivity foam sheet material, comprised of urethane foam and a lossy carbon loading. C-RAM PIM-465 FR absorbs RF microwave energy across 700 MHz through 3 GHz. frequencies. C-RAM PIM-465 FR has proven to be ideal for PIM reduction, mainly used to cover metallic surfaces. It can also be used to cover fences. The open-cell structure permits airflow freely through the absorber.

C-RAM PIM-645 is a line of outdoor isolation foam sheet material, comprised of urethane foam and a lossy carbon loading. C-RAM PIM-645 absorbs RF microwave energy across 700 MHz through 3 GHz. frequencies. C-RAM PIM-645 has proven to be ideal for PIM reduction and isolation between antennas; it can also be used to cover fences to de-couple adjacent antennas, and shield or isolate equipment. The open-cell structure permits airflow freely through the absorber. When used outdoors, rain will also freely drain from the product.

C-RAM PIM-645 FR is a line of flame retardant indoor reflectivity foam sheet material, comprised of urethane foam and a lossy carbon loading. C-RAM PIM-645 FR absorbs RF microwave energy across 700 MHz through 3 GHz. frequencies. C-RAM PIM-645 FR has proven to be ideal for PIM reduction and isolation between antennas; it can also be used to cover fences to de-couple adjacent antennas, and shield or isolate equipment. The open-cell structure permits airflow freely through the absorber.