Abstract: A bulk RF absorber and a method for constructing same. The absorber is composed of multiple sheets of a reticulated dielectric material, each sheet being coated with at least one layer of radiation absorbing material to create a radiation absorption gradient across a width dimension of the sheet. The sheets are stacked with their respective absorption gradients aligned to form the bulk absorber. In one embodiment, the coated sheets are constructed by lengthwise feeding the dielectric material through a sputtering region and interposing a partial mask between the sputtering material and the face of the dielectric material. The contour of an edge of the mask, the sputtering rate and feed rate determine the resulting absorption gradient of the coated dielectric material. In another embodiment, a dipping process is used to coat each sheet with radiation absorbing material.

Abstract: A bulk RF absorber and a method for constructing same. The absorber is composed of multiple sheets of a reticulated dielectric material, each sheet being coated with at least one layer of radiation absorbing material to create a radiation absorption gradient across a width dimension of the sheet. The sheets are stacked with their respective absorption gradients aligned to form the bulk absorber. In one embodiment, the coated sheets are constructed by lengthwise feeding the dielectric material through a sputtering region and interposing a partial mask between the sputtering material and the face of the dielectric material. The contour of an edge of the mask, the sputtering rate and feed rate determine the resulting absorption gradient of the coated dielectric material. In another embodiment, a dipping process is used to coat each sheet with radiation absorption material.