A band-pass filter includes first to sixth stage resonators. Each resonator includes a resonator conductor portion formed of a conductor line. The resonator conductor portion has a first end and a second end which are opposite ends of the conductor line. The resonator conductor portion of each of the first and sixth stage resonators includes a narrow portion, a first wide portion located between the narrow portion and the first end, and a second wide portion located between the narrow portion and the second end. Each of the first and sixth stage resonators is lower in unloaded Q than the other resonators.

An on-chip microwave filter circuit includes a substrate formed of a first material that exhibits at least a threshold level of thermal conductivity, wherein the threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum computing circuit operates. The filter circuit further includes a dispersive component configured to filter a plurality of frequencies in an input signal, the dispersive component including a first transmission line disposed on the substrate, the first transmission line being formed of a second material that exhibits at least a second threshold level of thermal conductivity, wherein the second threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum computing circuit operates. The dispersive component further includes a second transmission line disposed on the substrate, the second transmission line being formed of the second material.

Transmission-line filtering with enhanced frequency response is disclosed. In an example aspect, an apparatus includes a transmission-line filter to enhance a frequency response of a filtering operation. The transmission-line filter includes an input port, an output port, and multiple transmission-line base units. The multiple transmission-line base units are disposed between the input port and the output port and are coupled to the input port and the output port. Each of the multiple transmission-line base units includes a respective transmission line of multiple transmission lines. At least one transmission-line base unit of the multiple transmission-line base units includes a multi-resonant circuit.

A radio frequency filter includes a first conductive pattern; a second conductive pattern connected to a first point of the first conductive pattern and extended; a third conductive pattern connected to a second point of the first conductive pattern and extended to surround a portion of the second conductive pattern; a fourth conductive pattern; a fifth conductive pattern connected to a third point of the fourth conductive pattern and extended; and a sixth conductive pattern connected to a fourth point of the fourth conductive pattern and extended to surround a portion of the fifth conductive pattern. The first conductive pattern extends toward the fourth conductive pattern and the fourth conductive pattern extends toward the first conductive pattern. A distance between the first conductive pattern and the fourth conductive pattern is greater than or equal to a distance between the third conductive pattern and the sixth conductive pattern.

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.

An electromagnetic field band-stop filter includes a plurality of unit structures that have reflection characteristics on an electromagnetic wave of a predetermined frequency. Each of the plurality of unit structures includes: a plurality of electrode parts each of which is disposed along a side of a polygon in a non-contact manner with another electrode part; and a plurality of conductor parts which are provided for the plurality of electrode parts on a one-to-one basis and each of which has at least one bent portion between one end and other end, the one ends of the plurality of conductor parts being connected to the electrode parts on a one-to-one basis and the other ends of the plurality of conductor parts being connected at one point on an inner side of the electrode parts in the individual unit structure. The plurality of unit structures are regularly and two-dimensionally disposed by disposing electrode parts of the plurality of unit structures to be adjacent to each other with a spacing that reflects the predetermined frequency.

A semiconductor technology implemented high-frequency channelized filter includes a dielectric substrate with metal traces disposed on one of two major surfaces of the substrate. An input and output port disposed on the substrate and one of the metal traces carrying a high-frequency signal to be filtered between the input and output port. Other of the metal traces are connected to the one metal trace at intervals along the length of the one metal trace each providing a reactance to the high-frequency signal where the reactance varies with frequency and additional traces of the metal traces serving as a reference ground for the one metal trace and the other metal traces. A silicon enclosure mounted to the substrate with a first planar surface with cavities in the enclosure that extend through the first surface, and internal walls within the silicon enclosure defining the cavities. A layer of conductive metal covers the first planar surface, cavities and the internal walls. The silicon enclosure having substantially continuous areas of metal on the first planar surface about the periphery of the silicon enclosure that engage corresponding areas of the additional traces about the periphery of the substrate. The cavities surround the respective other metal traces with the internal cavity walls engaging the additional traces adjacent the respective other metal traces to individually surround each of the other metal traces with a conductive metal thereby providing electromagnetic field isolation between each of the other metal traces.

A technology for a dual-common port multi-bandpass filter is described. The dual-common port multi-bandpass filter can include two or more analog filters. The dual-common port multi-bandpass filter can include a first common port coupled to an input of each of the two or more analog filters. Each analog filter can be configured to filter one or more frequency bands. The dual-common port multi-bandpass filter can include a second common port coupled to an output of each of the two or more analog filters. Each input of each of the two or more analog filters is impedance matched with the first common port. Each output of each of the two or more analog filters is impedance matched with the second common port.

A first switch is configured to open and close connection between an end part of a first transmission line and ground, and a second switch is configured to open and close connection between an end part of a third transmission line and ground.

A filter for electromagnetic noise comprising: a printed circuit board (5) having conductor tracks, having a first side and having a second side opposite the first side; a first busbar (1), which is secured on the first side of the printed circuit board (5) and is electrically connected to at least one of the conductor tracks; and a second busbar (2), which is secured on the second side of the printed circuit board (5) and is electrically connected to at least one of the conductor tracks. The printed circuit board (5) is arranged between the first busbar (1) and the second busbar (2) for the insulation thereof.