A magnetic field application device according to an embodiment includes a first coil assembly and a second coil assembly spaced apart in parallel from each other, a power supply configured to apply respective currents to the first coil assembly and the second coil assembly, a controller, and a resonator accommodation unit disposed between the first coil assembly and the second coil assembly, wherein each of the first coil assembly and the second coil includes a coil configured to generate a magnetic field, a guide member connected to a terminal of the coil, a magnetic material mount connected to a terminal of the guide member, and a magnetic material fixed to the magnetic material mount, and wherein the controller is configured to control the currents applied from the power supply to the first coil assembly and the second coil assembly.

A magnetic field application device according to an embodiment includes a first coil assembly and a second coil assembly spaced apart in parallel from each other, a power supply configured to apply respective currents to the first coil assembly and the second coil assembly, a controller, and a resonator accommodation unit disposed between the first coil assembly and the second coil assembly, wherein each of the first coil assembly and the second coil includes a coil configured to generate a magnetic field, a guide member connected to a terminal of the coil, a magnetic material mount connected to a terminal of the guide member, and a magnetic material fixed to the magnetic material mount, and wherein the controller is configured to control the currents applied from the power supply to the first coil assembly and the second coil assembly.

A tunable frequency selective limiter is disclosed. In one or more embodiments, the tunable frequency selective limiter includes a first electrically conductive path. The tunable frequency selective limiter also includes a ferrimagnetic layer disposed adjacent to the first electrically conductive path. The tunable frequency selective limiter further includes a second electrically conductive path coiled around the first electrically conductive path and the ferrimagnetic layer. An electromagnetic current transmitting through the second electrically conductive path produces a magnetic field coupled to the ferrimagnetic layer. The tunable frequency selective limiter further includes a dielectric layer, wherein the ferrimagnetic layer is disposed on the dielectric layer. The portions of the second electrically conductive path that are at the interface of the dielectric layer and the ferrimagnetic layer may be embedded into the dielectric layer or may be disposed on the surface of the dielectric layer.

A tunable frequency selective limiter is disclosed. In one or more embodiments, the tunable frequency selective limiter includes a first electrically conductive path. The tunable frequency selective limiter also includes a ferrimagnetic layer disposed adjacent to the first electrically conductive path. The tunable frequency selective limiter further includes a second electrically conductive path coiled around the first electrically conductive path and the ferrimagnetic layer. An electromagnetic current transmitting through the second electrically conductive path produces a magnetic field coupled to the ferrimagnetic layer. The tunable frequency selective limiter further includes a dielectric layer, wherein the ferrimagnetic layer is disposed on the dielectric layer. The portions of the second electrically conductive path that are at the interface of the dielectric layer and the ferrimagnetic layer may be embedded into the dielectric layer or may be disposed on the surface of the dielectric layer.

Adaptions and improvements to coaxial metal powder filters include distributing a dissipative matrix mixture comprising superconductive material, metal powder, epoxy, and/or magnetic material within a volume defined by an outer tubular conductor and inner conductor. The frequency response of the filter may be tuned by exploiting the energy gap frequency of superconductive material in the dissipative matrix. The inner surface of the outer tubular conductor may be covered with a superconductive material. For a dissipative matrix comprising magnetic material or superconductive powder particles of a certain size, an external magnetic field can be applied to tune the frequency response of the filter.

Adaptions and improvements to coaxial metal powder filters include distributing a dissipative matrix mixture comprising superconductive material, metal powder, epoxy, and/or magnetic material within a volume defined by an outer tubular conductor and inner conductor. The frequency response of the filter may be tuned by exploiting the energy gap frequency of superconductive material in the dissipative matrix. The inner surface of the outer tubular conductor may be covered with a superconductive material. For a dissipative matrix comprising magnetic material or superconductive powder particles of a certain size, an external magnetic field can be applied to tune the frequency response of the filter.

A high-frequency oscillator includes an electric resonant circuit, and a high-frequency welding system and a method for controlling the frequency uses a high-frequency oscillator, in particular in a high-frequency welding system. The electric resonant circuit includes at least one electronic component having an inductance and at least one capacitor having a capacitance. At least one additional magnetic coil is associated with the electronic component and can electronically influence the inductance of the electronic component.

Adaptions and improvements to coaxial metal powder filters include distributing a dissipative matrix mixture comprising superconductive material, metal powder, epoxy, and/or magnetic material within a volume defined by an outer tubular conductor and inner conductor. The frequency response of the filter may be tuned by exploiting the energy gap frequency of superconductive material in the dissipative matrix. The inner surface of the outer tubular conductor may be covered with a superconductive material. For a dissipative matrix comprising magnetic material or superconductive powder particles of a certain size, an external magnetic field can be applied to tune the frequency response of the filter.

Adaptions and improvements to coaxial metal powder filters include distributing a dissipative matrix mixture comprising superconductive material, metal powder, epoxy, and/or magnetic material within a volume defined by an outer tubular conductor and inner conductor. The frequency response of the filter may be tuned by exploiting the energy gap frequency of superconductive material in the dissipative matrix. The inner surface of the outer tubular conductor may be covered with a superconductive material. For a dissipative matrix comprising magnetic material or superconductive powder particles of a certain size, an external magnetic field can be applied to tune the frequency response of the filter.

A high-frequency oscillator includes an electric resonant circuit, and a high-frequency welding system and a method for controlling the frequency uses a high-frequency oscillator, in particular in a high-frequency welding system. The electric resonant circuit includes at least one electronic component having an inductance and at least one capacitor having a capacitance. At least one additional magnetic coil is associated with the electronic component and can electronically influence the inductance of the electronic component.