Dielectric filter, antenna duplexer, and communications appliance
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsTomoya Maekawa, Hiroshi Kushitani, Hiroshi Shigemura, Toru Yamada, Toshio Ishizaki, Hideaki Nakakubo
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Abstract
A dielectric filter, has a plurality of resonators; and at least one transmissions line provided among said plurality of resonators, wherein a band rejection characteristic is formed around a resonance frequency of said resonator, and a line length of said transmission line is shorter than ¼ of a wavelength corresponding to the resonance frequency of said resonator.
Claims40
A dielectric filter, comprising:
- a plurality of resonators;
- and
- at least one transmission line provided among said plurality of resonators,
- wherein a band rejection characteristic is formed around a resonance frequency of said resonator, and a line length of said transmission line is shorter than ¼ of a wavelength corresponding to the resonance frequency of said resonator.
The dielectric filter according to any one of 1 to 8, wherein a line length of said transmission line is at least equal to or longer than {fraction (1/102)} of a wavelength corresponding to a resonance frequency of said resonator.
A dielectric filter comprising at least one transmission line, a plurality of resonators connected to said transmission line, and a plurality of capacitors provided between said resonator and said transmission line, and forming a band rejection characteristic around the resonance frequency of the resonator,
- wherein a plurality of values of capacitances of said capacitors are different to each other.
A dielectric filter having a layered structure, comprising:
- a first shield electrode;
- a dielectric layer (1) provided on said first shield electrode;
- a plurality of resonator electrodes provided on said dielectric layer (1);
- a dielectric layer (2) provided on said plurality of resonator electrodes;
- a transmission line electrode which are provided on said dielectric layer (2) and whose both ends are input/output terminals;
- a plurality of capacitors connected to said transmission line electrode, provided on same dielectric layer (2), positioned opposite said plurality of resonator electrodes partially through said dielectric layer (2);
- a dielectric layer (3) provided on said transmission line electrode and said plurality of capacitor electrodes;
- a second shield electrode provided on said dielectric layer (3);
- and
- side electrodes provided on sides, wherein
- a band rejection characteristic is formed around a resonance frequency of said resonator;
- and
- an area of said resonator electrode opposite said capacitor electrode through said dielectric layer (2) is different each other from an area of said capacitor electrode.
A dielectric filter, comprising:
- a plurality of resonators;
- at least one transmission line provided among said plurality of resonators;
- and
- a capacitor provided between said resonator and said transmission line,
- wherein:
- a band rejection characteristic is formed around a resonance frequency of said resonator;
- a line length of said transmission line is shorter than ¼ of a length of a waveform corresponding to a resonance frequency of said resonator;
- and
- said plurality of capacitors have different capacity values.
A dielectric filter, comprising:
- a plurality of resonators;
- and
- at least one transmission line provided among said plurality of resonators,
- wherein a band rejection characteristic is formed around a resonance frequency of said resonator, and a line length of said transmission line is longer than ¼ of a wavelength corresponding to the resonance frequency of said resonator.
Dependencies are inferred from the claim text.