High-selectivity double-frequency waveguide filter based on linear structure

The invention discloses a high-selectivity double-frequency waveguide filter based on a linear structure. The high-selectivity double-frequency waveguide filter comprises a rectangular cavity, first, second, third and fourth resonant metal columns, a resonant bimetal column, a bent short-circuit metal column, first, second and third short-circuit metal columns, and first and second coupling diaphragms, wherein the first, second, third and fourth resonant metal columns, the resonant bimetal column, the bent short-circuit metal column, the first, second and third short-circuit metal columns, the first and second coupling diaphragms are distributed in the cavity; two feed ports are distributed at the front end and the rear end of the cavity; the first resonant metal column, the third resonant metal column and the resonant bimetal column form a high-frequency passband resonator, the second resonant metal column, the fourth resonant metal column and the bent short-circuit metal column form a low-frequency passband