Directional coupler

Abstract

Abstract PURPOSE:To obtain a sufficient directivity at a coupling frequency band by coating and arranging a coated dielectric to increase the effective dielectric constant more than the dense coupling part onto the coarse coupling part. CONSTITUTION:A coarse coupling section 4a and a dense coupling section 4b having an electric length equal to nearly 1/4 wavelength of the center frequency of the coupling frequency band are formed continuously in the coupling section 4 and the coated dielectric substance 5 having a higher effective dielectric constant than the close coupling part 4b is provided. The signal fed to an input terminal 1a of a couple of center conductors 1, 1 is outputted from an output terminal 1c via the coarse coupling section 4a and the dense coupling section 4b, then the coated dielectric substance 5 provided on the coarse coupling section 4a reduce the phase speed difference of the balanced/unbalanced mode. Thus, the signal is sent while the directivity is improved in the coupling frequency band.

Inventors

• 👤 Junichi Maruta

Bibliographic Details