Multi-pole filters are provided herein. A multi-pole filter includes a substrate having a first resonator layer on a first side of the substrate and a second resonator layer that is electrically coupled to the first resonator layer and is on a second side of the substrate that is opposite the first side of the substrate.

An architecture for, and techniques for fabricating, a cryogenic microwave filter having reduced Kapitza resistance are provided. In some embodiments, the cryogenic microwave filter can comprise a substrate and a conductive line. The substrate can be formed of a material having a thermal conductivity property that sufficiently reduces Kapitza resistance in the cryogenic environment. The conductive line can be formed in a recess of the substrate and facilitate a filter operation on a microwave signal propagated in a cryogenic environment. In some embodiments, the conductive line can be formed according to a sintering technique that can reduce Kapitza resistance.

An electrical filter structure for forwarding an electrical signal from a first port to a second port in a frequency selective manner, wherein the filter is an edge-coupled filter, the filter comprising: a plurality of coupled line sections coupled in a series, comprising at least a first coupled line section and a last coupled line section; wherein the first port is connected with the first of the coupled line sections using a first transmission line; wherein the second port is connected with the last of the coupled line sections using a second transmission line; wherein the electrical filter comprises an open stub; wherein a length of the open stub is chosen such that an electrical length of the open stub is equal, within a tolerance of +/−20 percent, to a fourth of a wavelength of a signal having a frequency of twice a passband center frequency of the filter.

An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

An electrical filter structure for forwarding an electrical signal from a first port to a second port in a frequency selective manner, wherein the filter is an edge-coupled filter, the filter comprising: a plurality of coupled line sections coupled in a series, comprising at least a first coupled line section and a last coupled line section; wherein the first port is connected with the first of the coupled line sections using a first transmission line; wherein the second port is connected with the last of the coupled line sections using a second transmission line; wherein the electrical filter comprises an open stub; wherein a length of the open stub is chosen such that an electrical length of the open stub is equal, within a tolerance of +/20 percent, to a fourth of a wavelength of a signal having a frequency of twice a passband center frequency of the filter.

A band pass filter (1) includes two resonators (8) and (10) including respectively linear conductors (9) and (11) disposed inside a dielectric substrate (2), and a pair of input-output lines (13) and (14) to which the two resonators (8) and (10) are connected in parallel. Both ends of the linear conductor (9) of the resonator (8) are left open. The resonator (10) includes vias (12A) and (12B) through which both ends of the linear conductor (11) of the resonator (10) are connected to a ground conductor (6) on a first surface (2A) of the dielectric substrate (2). The pair of input-output lines (13) and (14) include respectively vias (15A) and (15B) for connection to a ground conductor (7) that is disposed on a second surface (2B) of the dielectric substrate (2).

An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

An architecture for, and techniques for fabricating, a cryogenic microwave filter having reduced Kapitza resistance are provided. In some embodiments, the cryogenic microwave filter can comprise a substrate and a conductive line. The substrate can be formed of a material having a thermal conductivity property that sufficiently reduces Kapitza resistance in the cryogenic environment. The conductive line can be formed in a recess of the substrate and facilitate a filter operation on a microwave signal propagated in a cryogenic environment. In some embodiments, the conductive line can be formed according to a sintering technique that can reduce Kapitza resistance.

An architecture for, and techniques for fabricating, a cryogenic microwave filter having reduced Kapitza resistance are provided. In some embodiments, the cryogenic microwave filter can comprise a substrate and a conductive line. The substrate can be formed of a material having a thermal conductivity property that sufficiently reduces Kapitza resistance in the cryogenic environment. The conductive line can be formed in a recess of the substrate and facilitate a filter operation on a microwave signal propagated in a cryogenic environment. In some embodiments, the conductive line can be formed according to a sintering technique that can reduce Kapitza resistance.

A microstrip DC block includes a first signal line having a first signal line end and a first centreline (C.sub.1); a second signal line having a second signal line end and a second centreline (C.sub.2); a first spur-line extending from the first signal line end towards the second signal line end; a first stepped impedance line extending from the first signal line end towards the second signal line end, wherein the first stepped impedance line is parallel to the first spur line; a second spur-line extending from the second signal line end towards the first signal line end; a second stepped impedance line extending from the second signal line end towards the first signal line end, wherein the second stepped impedance line is parallel to the second spur line, and wherein the second stepped impedance line is coupled to the first stepped impedance line.