Simple dielectric waveguide bandpass filter

A dielectric waveguide bandpass filter is developed which consists of two, parallel-coupled, dielectric-waveguide gratings, each having a distributed load at one end. This structure gives the filter a low passband loss (probably less than 1 dB for the case of tapered grating spacing), and approximately 30 dB of attenuation in the stopband. The structure is considered to have potential uses in both millimeter-wave and integrated optics applications.