The invention discloses a
waveguide filter based on
electromagnetically induced transparency. The
waveguide filter comprises an upper cavity, a lower cavity, a medium substrate, a
signal input port and a
signal output port, wherein the upper cavity and the lower cavity form a standard rectangular
waveguide, and the medium substrate is inserted into the portion between the upper cavity and the lower cavity of the standard rectangular waveguide. A rectangular
metal ring, an out-of-
band rejection sheet, two rows of metallized through holes and a grounding epitaxial band are arranged in a
metal micro-strip structure on the front face of the medium substrate, and two symmetric C-shaped
resonance structures and a grounding epitaxial band are arranged on a
metal micro-strip structure on the back face of the medium substrate. The rectangular metal ring located on the front side of the medium substrate and the two symmetric C-shaped
resonance structures located on the back face of the medium substrate interact to generate a passing band of an electrically induced transparent window and a passing band of a magnetically induced transparent window, namely, the
electromagnetically induced transparency effect is formed, upper sidebands and lower sidebands of the passing bands of the
waveguide filter obtained through the effect are respectively provided with a transmission zero,
high selectivity is achieved, and the
waveguide filter is compact in structure and easy to design.