| 主权项 |
1. A tunable dual-band resonator structured such that a stub is added to each half-wavelength resonator, each thereof provided with half-wavelength resonator protrusions (capacity-component adjust parts), symmetric planes of the stubs, functioning as an electrical/magnetic wall, respectively, the dual-band resonator operating in two frequency-bands due to resonance in an odd-number mode and resonance in an even-number mode, and being capable of adjusting a resonator length such that the half-wavelength resonator serves as the resonator in the odd-number mode, while the half-wavelength resonator and the stub serve as the resonator in the even-number mode, thereby causing the odd-number mode to resonate on a low-frequency side, while causing the even-number mode to resonate on a high-frequency side, alternatively, enabling the odd-number mode to resonate on the high-frequency side, while enabling the even-number mode to resonate on the low-frequency side;
said dual-band resonator being made up of: an odd-number mode resonator in a shape including a ground conductor in a predetermined thickness disposed on the back surface of a dielectric body, and a strip conductor disposed on the top surface thereof, the relevant strip conductor being one length of a thin strip conductor cut off at an open-end thereof (a location where the strip is not linked), provided with a deeply retreated groove having a width g, one length of the strip conductor in a laterally symmetric shape, having a width d, being provided at the tip of the groove as well as the end face of the strip conductor; and an even-number mode resonator in such a shape as to be formed when the stub having a length l is connected to an end face on the opposite side of the open-end of the strip; wherein the dual-band resonator operating as the odd-number mode resonator, when the electric current flows to the symmetric planes of the stubs, while operating as the even-number mode resonator when the electric current does not flow to the symmetric planes; characterized in that a dielectric rod circular in cross section is provided in the space above the respective stubs, and a dielectric rod circular in cross section is provided in the space above the half-wavelength resonator protrusions (capacity-component adjust parts) of the half-wavelength resonator, thereby enabling resonance frequency in the even-number mode, and resonance frequency in the odd-number mode, to be tuned independently from each other. |
