Embodiments of a filter for electromagnetic radiation are disclosed herein. The filter includes a first glass-ceramic substrate having a first refractive index, a second glass-ceramic substrate having the first refractive index, and a first region disposed between the first glass-ceramic substrate and the second glass-ceramic substrate. The first region has a second refractive index that is less than the first refractive index. Further, the second glass-ceramic substrate is arranged substantially parallel to and spatially disposed from the first glass-ceramic substrate. The filter transmits at least 70% of electromagnetic radiation within a band of frequencies and reflects at least 80% of electromagnetic radiation outside the band of frequencies. The band of frequencies is located within the frequency range of 20 GHz to 100 GHz.