Comb-line type band pass filter

Abstract

Abstract PURPOSE:To obtain a band pass filter with excellent leading characteristic, small size, less insertion loss and excellent dielectric constant characteristic by providing a resonance element comprising plural rod conductors arranged in a line with the same polarity and an indirect coupling circuit coupling indirectly the resonance elements one another. CONSTITUTION:The indirect coupling circuit 5 consists of a transmission line such as a coaxial cable, a semi-rigid cable or a strip line and indirect coupling loop elements 62 and 65 connected between the line and when the loop element 62 and the resonance element 22 are coupled positively (or negatively), the loop element 65 and the resonance element 25 are coupled negatively (or positively). The axial length of the resonance elements 21-26 is formed nearly 1/4 lambda in electric length and the mechanical free end is opened electrically. Further, the length of the indirect coupling circuit 5 is selected to be 1/2 lambda (where lambdais the resonance wavelength) or an odd number multiple in electric length including the length of the indirect coupling loop elements 62 and 65.

Inventors

• 👤 Hiroshi Hatanaka
• 👤 博 畠中

Bibliographic Details