Filter

Abstract

A dielectric waveguide tube band-pass filter assuming lower characteristic change upon mounting, and having smaller dimensions and lower loss. Conductor layers (2a, 2c) are formed on the top and bottom surfaces of a dielectric substrate (1), wherein the top conductor layer 2a and the bottom conductor layer 2c are connected together through via-holes (3a). The via-holes (3a) are formed in at least two rows along the signal transfer direction. In the dielectric waveguide tube configured by the top and bottom conductor layers (2a, 2c) and the via-holes (3a), via-holes (3b) are arranged in the signal transfer direction at spacing equal to or below ½ of the in-tube wavelength to thereby configure resonators. The dielectric band-pass filter is configured by coupling adjacent resonators together through the via-holes (3b) configuring inductive windows. On the surface of the dielectric substrate (1), a co-planar line (4) including the conductor layer (2) as the ground and the conductor layer (2b) as a signal conductor is configured so as to overstride the inductive windows configured by the via-holes (3a).

Dependencies are inferred from the claim text.