A transmission line for transmitting radiofrequency range current between a first conductive element and a second conductive element, the transmission line comprising a signal current line and at least one return current line, the signal current line and the return current line(s) extending in parallel. Each current line comprises at least one first segment and at least one second segment. Each first segment is partially aligned with at least one adjacent second segment, aligned segments being separated by a first dielectric gap, and each aligned first segment and second segment forming a capacitive coupling across the first dielectric gap. This solution enables a transmission line which provides only small capacitive loading onto its surroundings, and which therefore can extend, e.g., through an antenna element without significantly affecting the performance of the antenna element.

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).

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.

This invention reduces, in a type of bandpass filter that is called a strip-line filter or a microstrip filter, a variation in filter characteristics that can occur in a case where the design of the first line and the second line is changed. The bandpass filter (filter 10) includes a ground conductor layer, n resonators (141 to 146), and first and second lines (lines 151, 152), wherein the first and second lines (lines 151, 152) are respectively connected to a third side (side R13) of a first resonator (resonator 141) and a seventh side (side R63) of an n-th resonator, a gap (G1) is provided in an area of a fourth side (side R14) which area is close to a second resonator (resonator 142), and a gap (G6) is provided in an area of an eighth side (side R64) which area is close to an n−1-th resonator (resonator 145).

Deterioration is reduced in filter characteristics in a type of bandpass filter that is called a strip-line filter or a microstrip filter. A bandpass filter (filter 10) includes a ground conductor layer (12), a plurality of resonators (141 to 146) arranged in a layer spaced from the ground conductor layer (12), a first line (line 151) connected to a first-pole resonator (141) and a second line (line 152) connected to a last-pole resonator (146), wherein a direction in which the first line (line 151) is drawn out from the first-pole resonator (141) and a direction in which the second line (line 152) is drawn out from the last-pole resonator (146) are opposite to each other.

The filter unit has a center frequency and comprises a first dielectric substrate, a first conducting plane, and at least one transmission arrangement. The at least one transmission arrangement comprises a shunt node which has a shunt connection to the conducting plane. The electrical length of the shunt connection defines the center frequency of the filter unit. The transmission arrangement further comprises a plurality of transmission lines connected in series between an input port and an output port, wherein each port is connectable to auxiliary systems with a system impedance. Moreover, each transmission line has a characteristic impedance and wherein the characteristic impedance of each transmission line is less than the system impedance.

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.

Deterioration is reduced in filter characteristics in a type of bandpass filter that is called a strip-line filter or a microstrip filter. A bandpass filter (filter 10) includes a ground conductor layer (12), a plurality of resonators (141 to 146) arranged in a layer spaced from the ground conductor layer (12), a first line (line 151) connected to a first-pole resonator (141) and a second line (line 152) connected to a last-pole resonator (146), wherein a direction in which the first line (line 151) is drawn out from the first-pole resonator (141) and a direction in which the second line (line 152) is drawn out from the last-pole resonator (146) are opposite to each other.

This invention reduces, in a type of bandpass filter that is called a strip-line filter or a microstrip filter, a variation in filter characteristics that can occur in a case where the design of the first line and the second line is changed. The bandpass filter (filter 10) includes a ground conductor layer, n resonators (141 to 146), and first and second lines (lines 151, 152), wherein the first and second lines (lines 151, 152) are respectively connected to a third side (side R13) of a first resonator (resonator 141) and a seventh side (side R63) of an n-th resonator, a gap (G1) is provided in an area of a fourth side (side R14) which area is close to a second resonator (resonator 142), and a gap (G6) is provided in an area of an eighth side (side R64) which area is close to an n−1-th resonator (resonator 145).

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, where 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.