WAVEGUIDE ULTRANARROW MICROWAVE FILTER Russian patent published in 2023 - IPC H01P1/20 

FIELD: radio engineering.

SUBSTANCE: relates to the filters. The waveguide filter contains a regular section of a rectangular waveguide, an inductive diaphragm and a cylindrical inductive pin in the center of the waveguide, as well as two additional cylindrical inductive pins located between the central pin and the ends of the waveguide symmetrically with respect to the central pin. All three pins are located on the same axis along the direction of propagation of the main electromagnetic wave of the rectangular waveguide, the radius of the central pin is greater than the radii of the peripheral pins, and the distance from one of the side walls of the rectangular waveguide to the center of each pin is less than the same distance to the other side wall. In addition, all three pins have rectangular ribs, regular along the height of the waveguide and located along the longitudinal axis passing through the centers of the pins, and the central pin has two symmetrical ribs along this axis, and the peripheral pins have one rib each located opposite the first or second rib of the center pin, respectively.

EFFECT: reduction of the longitudinal size of the filter to a value of 2.3λ, providing a relative bandwidth of less than 0.1% and improving the matching in the bandwidth, as well as the ability to select the center frequency without tuning elements.

4 cl, 5 dwg