Patent ID: 8878635

Claim:
A tunable band-pass filter comprising: a rectangular waveguide including a first waveguide part and a second waveguide part, which are acquired by dividing the rectangular waveguide along an E-plane of the rectangular waveguide at a center position of an H-plane in the rectangular waveguide; a metal plate sandwiched by the first waveguide part and the second waveguide part in such a way as to be parallel to the E-plane; at least one dielectric plate arranged in the rectangular waveguide in such a way as to extend along a longitudinal extension direction of the metal plate; and a drive mechanism changing a relative positional relationship between the dielectric plate and the metal plate from an outside, wherein the dielectric plate is arranged parallel to the H-plane, and wherein the drive mechanism flaps the dielectric plate around a portion near the metal plate to thereby change a relative angle formed by the dielectric plate and the metal plate.