| 摘要 |
PURPOSE:To obtain a coaxial dielectric filter whose characteristic is not deteriorated with a small size by providing plural resonance grooves to one major face of a dielectric base and providing a coupling groove between the resonator grooves so as to couple the two dielectric bases symmetrically in a way that each of resonance sections is opposite to each other. CONSTITUTION:Three resonance grooves 12 whose depth is changed stepwise in the lengthwise direction respectively are provided to one major side of each dielectric base 10 and a coupling groove 14 is provided between the resonance grooves 12. A ground conductor film is formed on the dielectric base 10 and a conductor film whose one end is short-circuited and whose other end is opened is formed in the said resonance slots 12 to constitute the resonance part of 1/4 wavelength. Moreover, the two dielectric base 10 are coupled symmetrically so that resonance parts are opposite to each other thereby constituting the coaxial filter. Lumped capacitors C1, C2 are inserted in the step in the equivalent circuit and the lengthwise size of the grooves is reduced thereby. |
