A filter device includes first to third resonators. Each of the first to third resonators includes a first line part and a second line part electrically connected to the first line part and having an impedance smaller than an impedance of the first line part. The impedance ratio in at least one of the first to third resonators is 0.3 or smaller. The shape of each of the second line part of the first resonator and the second line part of the second resonator is long in a direction orthogonal to a stacking direction and crossing the longitudinal direction of the second line part of the third resonator.

Disclosed are electrochemically tunable metamaterials which are capable of complete reversibility such that the metamaterial itself can physically disappear (out of the active region) and reappear later, in a controllable manner. Some variations provide an electrochemically tunable, solid-state metamaterial-based device comprising a plurality of metamaterial unit cells, wherein each of the metamaterial unit cells comprises: an ion conductor containing mobile metal ions; a first electrode in contact with the ion conductor, wherein the first electrode is contained in a metasurface negative space disposed on the ion conductor; a second electrode in contact with the ion conductor, wherein the second electrode is electrically isolated from the first electrode; and a metal-containing region containing one or more metals, wherein the metal-containing region is contained within a metasurface positive space disposed on the ion conductor.

Disclosed are electrochemically tunable metamaterials which are capable of complete reversibility such that the metamaterial itself can physically disappear (out of the active region) and reappear later, in a controllable manner. Some variations provide an electrochemically tunable, solid-state metamaterial-based device comprising a plurality of metamaterial unit cells, wherein each of the metamaterial unit cells comprises: an ion conductor containing mobile metal ions; a first electrode in contact with the ion conductor, wherein the first electrode is contained in a metasurface negative space disposed on the ion conductor; a second electrode in contact with the ion conductor, wherein the second electrode is electrically isolated from the first electrode; and a metal-containing region containing one or more metals, wherein the metal-containing region is contained within a metasurface positive space disposed on the ion conductor.

Provided are a transmission line module for a rotary traveling wave oscillator (RTWO) and a design method thereof. The transmission line module includes a substrate. The upper surface of the substrate is provided with a grounding metal layer, that is, a metal ground. The metal ground is provided with a rectangular groove. The rectangular groove penetrates front and rear sides of the metal ground along a length direction of the rectangular groove. The thickness of the rectangular groove is the same as the thickness of the metal ground. The rectangular groove is filled with a silicon dielectric plate that has the same shape and size as the rectangular groove. The upper surface of the silicon dielectric plate is provided with two parallel transmission lines along the length direction of the rectangular groove.

Provided are a transmission line module for a rotary traveling wave oscillator (RTWO) and a design method thereof. The transmission line module includes a substrate. The upper surface of the substrate is provided with a grounding metal layer, that is, a metal ground. The metal ground is provided with a rectangular groove. The rectangular groove penetrates front and rear sides of the metal ground along a length direction of the rectangular groove. The thickness of the rectangular groove is the same as the thickness of the metal ground. The rectangular groove is filled with a silicon dielectric plate that has the same shape and size as the rectangular groove. The upper surface of the silicon dielectric plate is provided with two parallel transmission lines along the length direction of the rectangular groove.

Tires formed of one or more tire plies are disclosed. In some implementations, tire plies may include a temperature sensor that may detect a temperature of a respective tire ply. The temperature sensor may include one or more split-ring resonators (SRRs), each having a resonance frequency that changes in response to one or more of a change in an elastomeric property or a change in the temperature of a respective one or more tire plies. In some aspects, the temperature sensor may include an electrically-conductive layer dielectrically separated from a respective one or more SRRs.

Tires formed of one or more tire plies are disclosed. In some implementations, tire plies may include a temperature sensor that may detect a temperature of a respective tire ply. The temperature sensor may include one or more split-ring resonators (SRRs), each having a resonance frequency that changes in response to one or more of a change in an elastomeric property or a change in the temperature of a respective one or more tire plies. In some aspects, the temperature sensor may include an electrically-conductive layer dielectrically separated from a respective one or more SRRs.

Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.

The present invention relates to a tunable waveguide resonator and a method of tuning a frequency of the tunable waveguide resonator. The waveguide resonator comprises a waveguide part having a plurality of walls where one of the plurality of walls at least partly comprises a tuning element. The tuning element has a first main surface facing toward a first main surface of an inner wall of one other wall of the plurality of walls. The tuning element is caused to, in response to a change in a temperature of the tuning element be reversibly displaced with respect to a reference plane of the first main surface of the tuning element along an extension perpendicular to the first main surface of the one other inner wall and whereby changing a dimension of a cavity of the tunable wave-guide resonator.

A radiofrequency (RF) resonator array device for use in magnetic resonance imaging (MRT), The RF resonator array device includes a substrate. An army of coupled split ring resonators are located on the substrate. Each of the coupled split ring resonators includes a first split ring resonator positioned on a first side of the substrate and a second split ring resonator positioned on a second side of the substrate located opposite the first side. The second split ring resonator is inductively coupled to the first split ring resonator. Methods of making and using the RF resonator device are also disclosed.