Comb-line dielectric filter

Abstract

Abstract PURPOSE:To make the attenuation at a low frequency skirt steep by prolonging the electric length of an inner conductor more than the 1/4 wavelength of the pass band center frequency, connecting one end of each inner conductor directly to the outer conductor and connecting the other end to the outer conductor via the inductance. CONSTITUTION:The length of the inner conductors 6-8 is longer slightly electrically than the 1/4 wavelength of the center frequency of the filter pass band, the inductance elements 12-14 provided to the upper face 2 of the dielectric block 1 are connected between the upper end of the inner conductors 6-8 and the outer conductor 9 to make the resonance frequency of the inner conductor coincident with the center frequency of the filter pass band. Moreover, the upper end of the inner conductors 6, 8 at both ends is connected to the device via input/output inductances 15, 16 to match the impedance in cooperation with the inductance elements 13, 14. Thus, the skirt characteristic of the low frequency is made step and a disturbing signal is blocked by a few stages and the device is made small in size and low in the cost.

Inventors

• 👤 Moriaki Ueno

Bibliographic Details