Provided is a filter capable of suppressing variation in characteristics. A filter has: a plurality of resonators each having a via electrode and a first strip line that is opposed to a first shielding conductor and connected to one end of the via electrode; a first coupling capacitive electrode that has a first comb-shaped electrode including a plurality of first electrodes and that is provided to the first resonator; and a second coupling capacitive electrode that is provided to the second resonator, that has a second comb-shaped electrode including a plurality of second electrodes, and that is formed on the same layer as that of the first coupling capacitive electrode, wherein the first and second electrodes are arranged so as to be adjacent to each other.

Embodiments of the present invention provide an electrical filter structure having a direct-coupled-stub filter (DCSF). The lengths of the transmission line portions can be arranged such that electrical lengths of the transmission line portions are shorter, by at least 10 percent, than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter structure. Moreover, lengths of the stubs can be selected so that the electrical lengths of the stubs are longer, by at least 2%, than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter structure. The filter structures of embodiments of the present invention can advantageously improve filter characteristics without changing the topological structure of the filter.

A radio frequency power amplifier and a device are disclosed. A first microstrip line and a second microstrip line are coupled, one end of the second microstrip line is an open stub and another end of the second microstrip line is grounded; and the first microstrip line having a first width is connected to a first transmission line having a second width which is wider than the first width. Therefore, some harmonic bands suppression can be implemented independently. Furthermore, the harmonic termination is independent and may not impact one or more fundamental components during matching a network. In addition, it may not take up more space and is sufficiently compact. Furthermore, sufficient wide harmonic response bandwidth can be provided.

A filter includes first and second resonators and first and second stub resonators. Each of the first and second resonators includes a first conductor part and a second conductor part electrically connected to the first conductor part and having an impedance smaller than an impedance of the first conductor part. The first stub resonator is electrically connected to the first conductor part of the first resonator. The second stub resonator is electrically connected to the first conductor part of the second resonator. The shape of the first stub resonator and the shape of the second stub resonator are different from each other.

Techniques relate to an on-chip Josephson parametric converter. A Josephson ring modulator includes four nodes. A lossless on-chip flux line is capacitively coupled to two adjacent nodes of the four nodes of the Josephson ring modulator. The lossless on-chip flux line has an input port configured to receive a pump drive signal that couples differentially to the two adjacent nodes of the of the Josephson ring modulator. The pump drive signal thereby excites a common mode of the on-chip Josephson parametric converter.

Surface scattering antennas with lumped elements provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the surface scattering antenna is a multi-layer printed circuit board assembly, and the lumped elements are surface-mount components placed on an upper surface of the printed circuit board assembly. In some approaches, the scattering elements are adjusted by adjusting bias voltages for the lumped elements. In some approaches, the lumped elements include diodes or transistors.

A resonant unit and a filter, where the resonant unit includes a dielectric substrate, a metal microstrip disposed on a plane of the dielectric substrate, where the metal microstrip is used as a signal input/output port, and a defected ground structure disposed on another plane opposite to the plane of the dielectric substrate, where the defected ground structure includes a ground loop and an interdigital structure located inside the ground loop, the interdigital structure includes multiple fingers, and the ground loop or at least one finger in the interdigital structure includes at least one embedded interdigital structure. Harmonic suppression capabilities of the resonant unit and the filter can be improved, and an area can be reduced.

A resonant unit and a filter, where the resonant unit includes a dielectric substrate, a metal microstrip disposed on a plane of the dielectric substrate, where the metal microstrip is used as a signal input/output port, and a defected ground structure disposed on another plane opposite to the plane of the dielectric substrate, where the defected ground structure includes a ground loop and an interdigital structure located inside the ground loop, the interdigital structure includes multiple fingers, and the ground loop or at least one finger in the interdigital structure includes at least one embedded interdigital structure. Harmonic suppression capabilities of the resonant unit and the filter can be improved, and an area can be reduced.

A device includes: a substrate; a first superconductor layer on the substrate, the first superconductor layer having a first kinetic inductance; and a second superconductor layer on the first superconductor layer, the second superconductor layer having a second kinetic inductance that is lower than the first kinetic inductance, in which the second superconductor layer covers the first superconductor layer such that the second superconductor layer and the first superconductor layer have a same footprint, with the exception of at least a first region where the second superconductor layer is omitted so that the first superconductor layer and the second superconductor layer form a circuit element having a predetermined circuit parameter.

A filter circuit includes an input node, an output node, a first filtering element and a second filtering element. The first filtering element has a first terminal coupled to the input node and a second terminal, and is configured to provide a first signal conducting path toward the second terminal for conducting a first signal received at the input node to the second terminal. The second filtering element has a first terminal coupled to the input node and a second terminal, and is configured to provide a second signal conducting path toward the output node for conducting a second signal received at the input node to the output node. The second terminal of the first filtering element and the second terminal of the second filtering element are open-circuit terminals.