Abstract: A reflectionless frequency filter circuit is provided. The reflectionless frequency filter circuit may include a first partial circuit including a first inductor and a first resistor connected in parallel with the first inductor, a first inverter connected in parallel with the first partial circuit, and a third partial circuit connected in series with the first inverter, and the third partial circuit may include a third inductor and a third resistor formed in a branch line between the first inverter and the third inductor.

Abstract: A reflectionless frequency filter circuit is provided. The reflectionless frequency filter circuit may include a first partial circuit including a first inductor and a first resistor connected in parallel with the first inductor, a first inverter connected in parallel with the first partial circuit, and a third partial circuit connected in series with the first inverter, and the third partial circuit may include a third inductor and a third resistor formed in a branch line between the first inverter and the third inductor.

Abstract: Provided is a resonator filter using conductive plates having a curved surface to connect an input/output coaxial connector to a resonator. The resonator filter includes: a plurality of resonators for resonating; an input/output coaxial connector; an input/output supporting unit formed between the input coaxial connector and one of the resonators and/or between an output supporting unit formed between the output coaxial connector and other resonator for electrically and mechanically supporting the input/output coupling; and a connecting unit for connecting the input/output supporting unit and the input/output coaxial connector, wherein the input/output supporting unit is a conductive plate with a curved surface having a center axis similar to the resonators.

Abstract: A realization method of a multiple passband filter that equalizes a group delay without using an external equalizer is disclosed. The realization method includes the steps of: a) calculating a transfer function based on poles and zeros; b) extracting an input/output coupling coefficient and a coupling matrix from the calculated transfer function as a network parameter; and c) physically designing and realizing elements of the filter to have the extracted network parameter.

Abstract: Provided is a resonator filter using conductive plates having a curved surface to connect an input/output coaxial connector to a resonator. The resonator filter includes: a plurality of resonators for resonating; an input/output coaxial connector; an input/output supporting unit formed between the input coaxial connector and one of the resonators and/or between an output supporting unit formed between the output coaxial connector and other resonator for electrically and mechanically supporting the input/output coupling; and a connecting unit for connecting the input/output supporting unit and the input/output coaxial connector, wherein the input/output supporting unit is a conductive plate with a curved surface having a center axis similar to the resonators.

Abstract: Provides is a screwdriver-and-nut wrench-combined tuning tool for radio frequency filter which is capable of preventing a movement of a tuning screw occurred when locking it with a tuning nut by making their combined body, preventing a difficulty of tuning resulted due to a separate use of a screwdriver and a nut wrench when a space for access to a tuning unit is not sufficient, and minimizing an interruption of turns of the tuning screw and the tuning nut by locking or turning the screwdriver and the nut wrench independently. The screwdriver-and-nut wrench-combined tuning tool for radio frequency filter comprises a case, a nut wrench positioned to rotate inside the case for turning or holding a tuning nut, a screwdriver positioned to rotate inside the nut wrench for turning or holding a tuning screw, a nut wrench locking unit that is fitted to the nut wrench or the case for locking the nut wrench; and a screwdriver locking unitthat is fitted to the case for locking the screwdriver.

Abstract: Provides is a screwdriver-and-nut wrench-combined tuning tool for radio frequency filter which is capable of preventing a movement of a tuning screw occurred when locking it with a tuning nut by making their combined body, preventing a difficulty of tuning resulted due to a separate use of a screwdriver and a nut wrench when a space for access to a tuning unit is not sufficient, and minimizing an interruption of turns of the tuning screw and the tuning nut by locking or turning the screwdriver and the nut wrench independently. The screwdriver-and-nut wrench-combined tuning tool for radio frequency filter comprises a case, a nut wrench positioned to rotate inside the case for turning or holding a tuning nut, a screwdriver positioned to rotate inside the nut wrench for turning or holding a tuning screw, a nut wrench locking unit that is fitted to the nut wrench or the case for locking the nut wrench; and a screwdriver locking unitthat is fitted to the case for locking the screwdriver.

Abstract: A realization method of a multiple passband filter that equalizes a group delay without using an external equalizer is disclosed. The realization method includes the steps of: a) calculating a transfer function based on poles and zeros; b) extracting an input/output coupling coefficient and a coupling matrix from the calculated transfer function as a network parameter; and c) physically designing and realizing elements of the filter to have the extracted network parameter.