bandpass filter

Abstract

Abstract PURPOSE:To obtain a miniature and inexpensive band-pass type filter BPF which can improve the attenuation characteristics easily and assuredly in a higher harmonic area, by adding an attenuation pole of a notch filter to a pass band of a high degree which is produced by the resonance of a high degree of a resonance element of the BPF. CONSTITUTION:The series resonance circuits A and B shown by broken lines are equivalent to screw rods 42 and 43 are form a notch filter which contains an attenuation pole in a higher harmonic area of a BPF. For the BPF, both rods 42 and 43 are controlled to change the length of a part protruded from the inside wall surface of an external conductor housing 31 as well as the distances between the tip parts at the open edge sides of rods 42 and 43 and the center conductors 38a and 39a of an input contact plug 38 and an output contact plug 39 respectively. Then an inductance component L or a capacity component C of both circuits A and B can be changed. Therefore the frequency of the attenuation pole of the notch filter, i.e., the resonance frequency of the notch filter can be changed in an extremely easy way.

Inventors

• 👤 Masao Nakamura
• 👤 政夫 中村

Bibliographic Details