Several embodiments are disclosed that provide for a frequency selective surface that can be placed like a radome on top of or under an existing radome or as a new radome on top of one or more radiating or receiving apertures or antennas to provide for a high-Q filter function to remove unwanted neighboring frequency interferences. The conformal structure comprises of an array of subwavelength electrically connected broken metallic rings and/or broken wires loaded with electromechanical resonators such as quartz or LiNbO3 crystal resonators, Bulk Acoustic Wave (BAW) resonators, and/or Surface Acoustic Wave (SAW) resonators at said breaks. When excited by an incident electromagnetic wave this collection of loaded rings and/or wires behaves as a filter which is capable of rejecting and/or passing frequencies over a narrow bandwidth. This medium can be formed into conformal shapes which can be placed over antennas and apertures as a frequency selective material, to introduce these frequency characteristics into the radiation pattern of the antenna, thereby reducing the gain of the antenna very sharply near the outside edges of the intended operating band. By loading the elements of this FSS with capacitors and/or inductors, additional spectral features can be added to the frequency response of the material to introduce broad pass and reject bands, to enable additional design flexibility for shared apertures. These reject or pass bands are significantly more narrow than achievable with traditional LC loaded FSS structures.