band pass filter

Abstract

In the resonator-coupled bandpass filter using the column wall waveguide, the error between the center frequency and the target center frequency is suppressed. A bandpass filter (1) includes: a substrate (2) made of a dielectric material sandwiched between a pair of conductor layers (3, 4); A column wall (11, 12) composed of conductor columns (11i, 12i), a plurality of resonators (22) in which the conductor layer (3, 4) is a pair of wide walls and the column walls (11, 12) are narrow walls ~24) for coupling. A recess (221-241) is formed in at least any one of the resonators (22-24), and the recess (221-241) penetrates any one of the wide walls (conductor layer 4) and reaches the inside of the substrate (2).

Description

technical field

[0001] The present invention relates to a bandpass filter that limits the passband of radio waves. Background technique

[0002] In a bandpass filter (BPF, BandpassFilter) that limits the passband of a signal propagating in a metal waveguide, the technology for adjusting the center frequency of the passband is described in Patent Document 1. figure 1 and figure 2 middle. of Patent Document 1 figure 1 and figure 2 The described BPF is a resonator-coupled BPF to which three-stage resonators are coupled.

[0003] The same number of conductor insertion holes as the number of configuration stages are formed on the side surface of the waveguide of the BPF. The conductor insertion hole is provided for inserting the conductor rod from the outside of the waveguide toward the inside. This BPF can adjust the center frequency by adjusting the amount of protrusion of the conductor rod into the waveguide.

[0004] The BPF of Patent Document 1 uses a metal waveguid...

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