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US 7,397,330 B2Granted
Filter and radio communication device using the same
AssigneeKabushiki Kaisha Toshiba
InventorsHiroyuki Kayano, Noritsugu Shiokawa, Mutsuki Yamazaki
Life of this patent
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Abstract
A filter includes a resonant unit which has a plurality of resonators respectively formed of each microstrip line and connected in cascade with one another, and a coupling unit which has at least one inter-resonator coupling of the resonant unit in an area within a range of ±45° (⅛-wavelength) in an electrical length from a voltage maximum point at a intermediate of the microstrip line.
Claims15
A filter, comprising:
- a resonant unit which has a plurality of resonators formed of microstrip lines and connected in cascade with one another;
- and
- a coupling unit which has a plurality of couplings of the resonant unit in an area within a range of ±45° (⅛-wavelength) in an electric length from voltage maximum points of the microstrip lines and at least one inter-resonator coupling of the resonant unit in an area within a range of ±45° (⅛-wavelength in an electric length from a voltage maximum point at an intermediate of the microstrip lines.
A filter, comprising:
- an input line which receives an input signal;
- an output line which outputs an output signal;
- a resonant unit which has a plurality of resonators each formed of a microstrip line including a first resonator coupled to the input line, a second resonator connected to the output line and a plurality of third resonators positioned at intermediates between the first resonator and the second resonator and connected in cascade with one another;
- a first coupling unit which has a coupling between the input line and the first resonator in a first area within a range of ±45° in an electric length from a voltage maximum point at an intermediate of the microstrip line of the first resonator;
- a second coupling unit which has a coupling between the second resonator and the output line in a second area within a range of ±45° in electric lengths from a voltage maximum point at an intermediate of the microstrip line of the second resonator;
- and
- at least two third coupling units which have inter-resonator couplings of the third resonators in third areas within ranges of ±45° in electric lengths from voltage maximum points at intermediates of the microstrip lines of the third resonators.
4 more elements
Dependencies are inferred from the claim text.