Printed-circuit isolation barrier for co-site interference mitigation

An apparatus includes an isolation barrier configured to absorb electromagnetic energy. The isolation barrier includes multiple layers stacked on one another. Each of the multiple layers includes at least one dielectric material, at least one thin-film resistive material carried by the at least one dielectric material, and conductive strips in electrical contact with the at least one thin-film resistive material. The isolation barrier also includes vias through the multiple layers. Multiple ones of the vias are positioned along each of the conductive strips, and the vias electrically couple the conductive strips in the multiple layers to one another. The isolation barrier is configured to guide the electromagnetic energy through the multiple layers to enable absorption of the electromagnetic energy by the at least one thin-film resistive material.