Abstract: A mixed-mode cavity filter is disclosed. The disclosed cavity filter includes: at least one first cavity configured to hold a metal coaxial resonator; and at least one second cavity configured to hold a dielectric resonator, where a first coupling window is formed in a wall formed between the first cavity and the second cavity, the first coupling window includes a horizontal window formed parallel to a bottom portion and a vertical window formed perpendicularly to the bottom portion, and the horizontal window and the vertical window overlap each other in at least a partial area. A mixed-mode filter according to an embodiment of the invention can achieve a small size and a light weight while providing low losses.

Abstract: A tunable filter for expanding tuning range includes: a housing, which has multiple cavities defined by partitions; a resonator contained in the cavity; at least one sliding member installed over the resonator; a main cover coupled to an upper portion of the housing; and at least one tuning element coupled to a lower portion of the sliding member and made of a metallic material. Tuning is accomplished by a sliding motion of the sliding member, and the resonator includes a cylindrical first conductor and a second conductor coupled to an upper portion of the cylindrical conductor, where a cross section of the second conductor is shaped as a circle with a portion removed such that an area of overlap between the tuning element and the second conductor is varied according to a sliding of the tuning element.

Abstract: A frequency-tunable filter using a sliding system is disclosed. The frequency-tunable filter includes: a housing, in which a multiple number of cavities are defined by partitions; a sub-cover, which is coupled to an upper portion of the housing and in which a guide groove is formed; at least one sliding member installed in the guide groove; a main cover coupled to an upper portion of the sub-cover; a resonator held in the cavity; and at least one tuning element coupled to a lower portion of the sliding member to be inserted inside the housing, where tuning is achieved by a sliding movement of the sliding member, and at least one first guide member is coupled to at least one side surface of the sliding member such that the first guide member guides a sliding movement by way of contact with the side surface of the guide groove.

Abstract: A multi-mode filter for realizing wide-band is disclosed. The multi-mode filter includes a housing; a plurality of cavities formed in the housing; a plurality of resonators located in each of the cavities; at least one connector formed through a side wall of the housing; and at least one coupling element connected to the at least one connector in the cavities, the at least one coupling element coupling the at least one connector with at least one of the resonators respectively, wherein each of the at least one coupling element has “T” shape in view of front section and “L” shape in view of side section.

Abstract: A multi-mode filter for realizing wide band using capacitive coupling and inductive coupling and capable of tuning coupling value is disclosed. The multi-mode filter includes a housing; a first cavity and a second cavity formed in the housing; a first resonator located in the first cavity, a second resonator located in the second cavity, a wall configured to separate the first cavity from the second cavity; and a first coupling element, wherein a groove is formed between the housing and the wall, the first coupling element is inserted in the groove in crossing direction to the wall, one part of the first coupling element is disposed in the first cavity, another part of the first coupling element is disposed in the second cavity, and the first coupling element is connected to a ground.

Abstract: A DC blocking device using impedance matching is disclosed. The disclosed DC blocking device comprises: a first strip line configured to receive a signal and including a first line section and a first joining section joined to a part where a signal is received; and a second strip line separated from the first strip line at a designated distance and including a second line section and a second joining section for joining an output signal, where coupling occurs from the first strip line to the second strip line, the first strip line and the second strip line each have at least one bending section, and the first line section and the second line section have smaller line widths than the first joining section and the second joining section. The disclosed DC blocking device has the advantage of minimizing spatial constraints when it is installed in a mobile communication apparatus, and of achieving proper coupling even if the length of the part of the DC blocking device where coupling occurs is reduced.

Abstract: A frequency tunable filter comprises a housing having a plurality of walls therein defining a plurality of cavities; a cover mounted on the housing; a plurality of resonators contained in the cavities; at least one sliding member located between the cover and the resonators; and a plurality of metal tuning elements attached to a lower part of the sliding member, wherein frequency tuning is performed by sliding of the sliding member.

Abstract: A DC blocking device of a small size is disclosed. The disclosed DC blocking device may include: an internal conductor where RF signals are inputted; and an external conductor electrically connected to a ground; wherein the internal conductor has an insertion groove, and an insertion conductor is inserted into the insertion groove without touching the internal conductor and at a designated distance, and the diameter of the external conductor in the portion where the insertion conductor is inserted is set to be different from the diameter of another portion. The disclosed DC blocking device has the advantages of minimizing the spatial constraint when the DC blocking device is mounted on a mobile communication device, and of achieving suitable coupling even if the length of the part where coupling is achieved is reduced in the DC blocking device.

Abstract: A tunable filter for enabling the adjustment of tuning characteristics includes: a housing, in which multiple cavities are defined by partitions; a resonator contained in the cavity; at least one sliding member installed over the resonator; a main cover coupled to an upper portion of the housing; and at least one tuning element coupled to a lower portion of the sliding member and made of a metallic material. The tuning element is coupled to the sliding member by a rotatable bolt, and the bolt is coupled to the tuning element at a point that is a particular distance away from a center of the tuning element. The tunable filter using a sliding system according to certain embodiments of the present invention has the advantage of enabling adjustment of tuning characteristics by way of the rotation of the tuning element, and accordingly, can be used adaptively in various environments.

Abstract: A tunable filter for expanding tuning range includes: a housing, which has multiple cavities defined by partitions; a resonator contained in the cavity; at least one sliding member installed over the resonator; a main cover coupled to an upper portion of the housing; and at least one tuning element coupled to a lower portion of the sliding member and made of a metallic material. Tuning is accomplished by a sliding motion of the sliding member, and the resonator includes a cylindrical first conductor and a second conductor coupled to an upper portion of the cylindrical conductor, where a cross section of the second conductor is shaped as a circle with a portion removed such that an area of overlap between the tuning element and the second conductor is varied according to a sliding of the tuning element.

Abstract: A frequency-tunable filter using a sliding system is disclosed. The frequency-tunable filter includes: a housing, in which a multiple number of cavities are defined by partitions; a sub-cover, which is coupled to an upper portion of the housing and in which a guide groove is formed; at least one sliding member installed in the guide groove; a main cover coupled to an upper portion of the sub-cover; a resonator held in the cavity; and at least one tuning element coupled to a lower portion of the sliding member to be inserted inside the housing, where tuning is achieved by a sliding movement of the sliding member, and at least one first guide member is coupled to at least one side surface of the sliding member such that the first guide member guides a sliding movement by way of contact with the side surface of the guide groove.

Abstract: A frequency tunable filter comprises a housing having a plurality of walls therein defining a plurality of cavities; a cover mounted on the housing; a plurality of resonators contained in the cavities; at least one sliding member located between the cover and the resonators; and a plurality of metal tuning elements attached to a lower part of the sliding member, wherein frequency tuning is performed by sliding of the sliding member.