A frequency variable filter includes variable resonators aligned in a predetermined direction, a coupling part configured to couple the adjacent variable resonators, and a coupling variable dielectric. The variable resonator includes a resonator and a frequency variable dielectric disposed in a movable state relative to the resonator, and is configured to be able to change a resonance frequency according to a position of the frequency variable dielectric with respect to the resonator. This applies to aligned variable resonators other than this variable resonator. The coupling variable dielectric is disposed in a movable state with respect to the coupling part and configured to adjust a coupling coefficient according to an amount of insertion into the coupling part. The coupling variable dielectric is disposed so that a movable surface of the coupling variable dielectric is on the same plane as a movable surface of the frequency variable dielectric.

A frequency variable filter includes variable resonators aligned in a predetermined direction, a coupling part configured to couple the adjacent variable resonators, and a coupling variable dielectric. The variable resonator includes a resonator and a frequency variable dielectric disposed in a movable state relative to the resonator, and is configured to be able to change a resonance frequency according to a position of the frequency variable dielectric with respect to the resonator. This applies to aligned variable resonators other than this variable resonator. The coupling variable dielectric is disposed in a movable state with respect to the coupling part and configured to adjust a coupling coefficient according to an amount of insertion into the coupling part. The coupling variable dielectric is disposed so that a movable surface of the coupling variable dielectric is on the same plane as a movable surface of the frequency variable dielectric.

A waveguide assembly is disclosed herein. In an embodiment, a waveguide assembly includes a circuit board, a housing and a waveguide filter channel. The circuit board has at least one waveguide interface formed from an electrically conductive material. The housing is configured to be attached to the circuit board so as to align with the at least one waveguide interface. The waveguide filter channel is formed between the circuit board and the housing, with the circuit board and the housing each forming at least a portion of the waveguide filter channel. The waveguide filter channel is configured to at least one of (i) receive a radio frequency signal from the at least one waveguide interface or (ii) output the radio frequency signal to the at least one waveguide interface.

A waveguide assembly is disclosed herein. In an embodiment, a waveguide assembly includes a circuit board, a housing and a waveguide filter channel. The circuit board has at least one waveguide interface formed from an electrically conductive material. The housing is configured to be attached to the circuit board so as to align with the at least one waveguide interface. The waveguide filter channel is formed between the circuit board and the housing, with the circuit board and the housing each forming at least a portion of the waveguide filter channel. The waveguide filter channel is configured to at least one of (i) receive a radio frequency signal from the at least one waveguide interface or (ii) output the radio frequency signal to the at least one waveguide interface.

A filtering device for use in a medical microwave delivery system is disclosed. The filtering device comprises a DC block and a microwave absorbing element. The microwave absorbing element is disposed around the DC block and/or around one or more elements within the DC block. Also disclosed is a medical microwave delivery system comprising a microwave generator system and the filtering device, wherein the filtering device is coupled to an output of the microwave generator system.

A filtering device for use in a medical microwave delivery system is disclosed. The filtering device comprises a DC block and a microwave absorbing element. The microwave absorbing element is disposed around the DC block and/or around one or more elements within the DC block. Also disclosed is a medical microwave delivery system comprising a microwave generator system and the filtering device, wherein the filtering device is coupled to an output of the microwave generator system.

A power cable for transmitting electrical power, the cable includes at least two electrical conductors extending mainly along a power transmission axis, a first of the conductors called the external conductor surrounding a second of the conductors called the internal conductor along the axis, at least one insert arranged between the internal conductor and the external conductor, the insert extending over only part of the cable along the axis, the insert introducing a first impedance between the internal conductor and the external conductor with a value different from a second impedance between the internal conductor and the external conductor outside of the part of the cable over which the insert extends.

A current filter externally coupled to a cable includes a coupling portion coupled to a cable portion to surround the cable portion including at least one cable, the coupling portion including a flexible metal, and a ground portion detachably attached to the coupling portion and transmitting a current flowing through the coupling portion to a ground plane.

A filter cable, which solves the problem that devices which can better cope with various problems in complex electromagnetic environment and have simple and reasonable structural design are lacking in the related art. The filter cable comprises a core wire; the core wire comprises an insulating substrate and a first conductor layer surrounding the insulating substrate; the first conductor layer has a first etching pattern; the first etching pattern is distributed along the axial direction of the filter cable; and the first etching pattern is used to make the filter cable equivalent to a first filter circuit to realize the filtering function.

A band-stop filter comprises: a housing having a top wall, a bottom wall and at least one side wall, the housing defining an internal cavity; a signal input port and a signal output port that are respectively disposed on one of the at least one side wall; a resonating element that is disposed in the internal cavity and includes a top, a bottom, and a side; and a transmission line that is disposed in the internal cavity and coupled between the signal input port and the signal output port, the transmission line comprising a coupling section that is coupled to the resonating element, wherein the coupling section is configured to surround more than half of the side of the resonating element and not directly contact the housing and the resonating element.