Engineered Materials, a subsidiary of PPG's aerospace division 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.