High frequency filter with a dielectric board element to provide electromagnetic couplings
AssigneeLK-Products Oy
InventorJari Pelkonen
Life of this patent
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Abstract
A coaxial resonator filter (1', 50, 50', 50") comprises a dielectric boardlike element (11, 51, 51") and on its surface at least one electrically conductive element (17, 19, 20, 21, 52) to provide an electromagnetic coupling to at least one coaxial resonator (3, 53). The dielectric boardlike element may be the same as the filter's base plate, in which case its outer surface comprises a continuous earth plane (55), or it may be parallel to a separate electrically conductive base plate (56). Link (17), tap (19) and capacitive (20) coupling elements can be realized on the surface of the dielectric board.
Claims16
A high-frequency filter comprising:
- a first coaxial resonator including a first inner conductor and a first outer conductor;
- a second coaxial resonator including a second inner conductor and a second outer conductor, each of said first and second coaxial resonators including a top end and a short circuited bottom end, and an air gap existing between each said respective inner and outer conductors;
- a base plate attached to the short circuited bottom ends of said first and second coaxial resonators;
- a dielectric board including a first hole and a second hole therethrough;
- and
- at least one electrically conductive element on a surface of said dielectric board to provide an electromagnetic coupling to at least one of said first and said second coaxial resonators, wherein said first inner conductor extends through said first hole, said second inner conductor extends through said second hole and said dielectric board is located at a distance in the direction toward the base plate from said top end of said at least one of said first and second coaxial resonators to which said dielectric board is coupled.
A duplex filter for filtering a transmitting and receiving signal in a radio apparatus in which the transmission and reception occur via one and the same antenna, comprising:
- at least a first coaxial resonator including a first inner conductor and a first outer conductor, and a second coaxial resonator including a second inner conductor and a second outer conductor, each of said first and second coaxial resonators including a top end and a short circuited bottom end;
- a base plate attached to the short circuited bottom end of said first and second coaxial resonators;
- a dielectric board including a first hole and a second hole there through;
- and
- at least one electrically conductive element on a surface of said dielectric board to provide an electromagnetic coupling to at least one of said first and said second coaxial resonators, wherein said first inner conductor extends through said first hole, said second inner conductor extends through said second hole and said dielectric board is located at a distance in the direction toward the base plate from said top end of said at least one of said first and second coaxial resonators to which said dielectric board is coupled.
Dependencies are inferred from the claim text.