Full Title

Auxiliary devices (coupling devices of the waveguide type H01P5/00) > Frequency-selective devices, e.g. filters > Hollow waveguide filters (H01P1/212, H01P1/213, H01P1/215, H01P1/219 take precedence) > Cascaded cavities; Cascaded resonators inside a hollow waveguide structure (H01P1/205 takes precedence)