Rigid and Castable Absorbers

PPG aerospace engineered materials cuming microwave Rigid and Castable Absorbers

Cuming Microwave manufactures a range of epoxy and silicone-based rigid and castable absorbers, loaded with high magnetic loss carbonyl iron and ferrite fillers. The proper filler and loading level can produce a very lossy material in UHF, microwave or millimeter wave frequencies. Unlike carbon based absorbing materials, these products utilize magnetic hysteresis loss and operate on the magnetic field. They are not electrically conductive and can be placed directly in contact with circuitry.

These products can be precision machined to complex final shapes from sheet, bar and rod stock, similar to aluminum or hard plastic. In addition, we can custom mold materials to shape, and can supply 2-component liquid resins for casting in place. These materials have been used to produce waveguide loads and absorptive housings, and they can be cast directly into RF device packages to attenuate unwanted noise and resonances.

Product

Name
Magnetic Silicone Casting Resin for UHF Frequencies
Category
Rigid and Castable Absorbers
Product Code
C-RAM: KFS
Safety Data Sheet
Product Data Sheet
English US
Name
Iron/Epoxy Casting Resin
Category
Rigid and Castable Absorbers
Product Code
C-RAM: KR
Safety Data Sheet
Product Data Sheet
English US
Name
Iron/Silicone Casting Resin
Category
Rigid and Castable Absorbers
Product Code
C-RAM: KRS
Safety Data Sheet
Product Data Sheet
English US
Name
Iron/Epoxy High Loss Stock
Category
Rigid and Castable Absorbers
Product Code
C-RAM: RGD
Safety Data Sheet
Product Data Sheet
English US

Product Details

RIGID EPOXY/IRON LOSSY MAGNETIC SHEET AND ROD STOCK - C-RAM RGD (330-1)

C-RAM RGD is a series of iron filled epoxy sheet materials having a high magnetic loss. It is available in several grades, as given in the table below, having a range of permittivities and complex permeabilities.

C-RAM RGD can be machined into terminations and loads for attenuators, waveguides, coaxial lines, and microstrip circuits. It can also be used for lowering the Q of cavities and eliminating unwanted resonances.

C-RAM RGD is a hard epoxy plastic and can be readily sawed, ground, milled or otherwise machined to complex shapes. Since it is ferromagnetic, it is easily held in place with magnetic chucks during machining.

The material has good thermal conductivity and can be used to dissipate heat, including that generated by its own magnetic loss mechanism. C-RAM KR (see Technical Bulletin 330) is the two component liquid resin version of RGD. It can be mixed, poured and cast into molds or cavities; when cured, it will have the properties of C-RAM RGD.

IRON FILLED EPOXY CASTING RESIN FOR RF LOADS - C-RAM KR (330-3)

C-RAM KR is a series of two-part liquid casting resin kits which can be used to mold waveguide terminations, attenuators, loads, and other RF absorbing parts. When cured into a solid, these parts have the same properties as parts machined from bars or blocks of C-RAM RGD (see Technical Bulletin 330-1). C-RAM KR is available in the same range of iron loadings as C-RAM RGD. In general, best performance is obtained at lower frequencies with high iron loadings, whereas low loadings work best at higher frequencies. Generally C-RAM KR-117 and -124 are the preferred materials below 20 GHz.

IRON FILLED SILICONE CASTING RESIN FOR RF LOADS - C-RAM KRS (330-4)

C-RAM KRS is a series of two part liquid RTV silicone casting resin kits which can be used to mold wave guide terminations, attenuators, loads, RF gaskets, and other radar absorber parts. When cured, the material converts to a flexible, high temperature silicone rubber. Parts cast from C-RAM KRS have the same performance as parts machined from bars or sheets of C-RAM RGD-S (See Technical Bulletin 330-2). C-RAM KRS is available in the same grades as C-RAM RGD-S.

C-RAM KRS will cure and adhere to itself or to other silicone surfaces, however, it will release from most substrates. If adhesion is required, an application of C-PRIME 215 is recommended.

LOSSY MAGNETIC UHF SILICONE CASTING RESIN - C-RAM KFS (330-6)

C-RAM KFS is a casting silicone for radar absorbers and loads, primarily for UHF and lower microwave bands. C-RAM KFS is a two-part liquid RTV silicone casting resin system. When cured, it converts to a flexible high temperature silicone rubber.

C-RAM KFS will adhere to itself and to most other silicones. It will release well from most other substrates unless an adhesion primer is used. C-PRIME 215 is recommended.

C-RAM KFS is used to mold loads and intricately contoured parts used for attenuation of signals and suppression of standing waves and RF noise, or to provide a lossy RF gasket. Pre-molded sheets of KFS are available as C-RAM FDSS (TB 310-5).C-RAM KRS will cure and adhere to itself or to other silicone surfaces, however, it will release from most substrates. If adhesion is required, an application of C-PRIME 215 is recommended.