A radio frequency antenna for radiating electromagnetic energy into a reservoir filled with a target material, the antenna being operatively connected to a feed transmission line. The antenna includes a waveguide, at least one slot formed in the outer waveguide layer, and a sleeve portion enclosing at least a portion of the waveguide. The sleeve portion comprises at least first and second dielectric layers where the permittivity of the second dielectric layer is higher than the permittivity of the first dielectric layer and the first dielectric layer is positioned in closer proximity to the waveguide than the second dielectric layer. When the antenna is inserted into the reservoir, the input impedance of the antenna remains matched to the feed transmission line for a wide range of target materials.

A radio frequency antenna for radiating electromagnetic energy into a reservoir filled with a target material, the antenna being operatively connected to a feed transmission line. The antenna includes a waveguide, at least one slot formed in the outer waveguide layer, and a sleeve portion enclosing at least a portion of the waveguide. The sleeve portion comprises at least first and second dielectric layers where the permittivity of the second dielectric layer is higher than the permittivity of the first dielectric layer and the first dielectric layer is positioned in closer proximity to the waveguide than the second dielectric layer. When the antenna is inserted into the reservoir, the input impedance of the antenna remains matched to the feed transmission line for a wide range of target materials.

A method of uniform RF-heating within a chamber is disclosed, which includes cyclically varying electromagnetic properties of a chamber according to a plurality of configuration, transmitting an alternating RF signal about a first frequency range between a first frequency and a second frequency from a transmitter into the chamber, measuring electromagnetic power at a random receiver location in the chamber for each of the plurality of configurations and at a predetermined resolution of frequency thereby generating a statistical distribution vs. frequency, applying a statistical test to the generated statistical distribution based on a predetermined statistical function, determining a standard deviation of the average received power as a function of frequency, choosing a third frequency range associated with a standard deviation lower than a second threshold, and choosing an operational frequency in the third frequency range which provides maximum heating depending on the material being heated.

A selective heating device may include a chamber, at least one heating element, and a circuit. The at least one heating element may selectively heat a first portion of a target in the chamber at a first energy level for a first period of time. The at least one heating element may also selectively heat a second portion of the target at a second energy level for a second period of time, wherein the second energy level and/or the second period of time are different from the first energy level and/or the first period of time; or refrain from heating a third portion of the target; or a combination thereof. The circuit may receive a heating instruction and control the at least one heating element based on the heating instruction.

A selective heating device may include a chamber, at least one heating element, and a circuit. The at least one heating element may selectively heat a first portion of a target in the chamber at a first energy level for a first period of time. The at least one heating element may also selectively heat a second portion of the target at a second energy level for a second period of time, wherein the second energy level and/or the second period of time are different from the first energy level and/or the first period of time; or refrain from heating a third portion of the target; or a combination thereof. The circuit may receive a heating instruction and control the at least one heating element based on the heating instruction.

In order to obtain an electromagnetic transmission device and an electromagnetic transmission system that emit high-power continuous microwaves stably onto a material or an irradiation target in electromagnetic heating systems and electromagnetic power transmission systems that are required to emit electromagnetic waves such as high-power microwaves, the electromagnetic transmission device, the power amplification device, and the electromagnetic transmission system emit, onto an irradiation target, electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle, or electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle and are amplified.

In order to obtain an electromagnetic transmission device and an electromagnetic transmission system that emit high-power continuous microwaves stably onto a material or an irradiation target in electromagnetic heating systems and electromagnetic power transmission systems that are required to emit electromagnetic waves such as high-power microwaves, the electromagnetic transmission device, the power amplification device, and the electromagnetic transmission system emit, onto an irradiation target, electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle, or electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle and are amplified.

The microwave power is distributed to microwave radiation elements arranged rotationally symmetrically around a reference line on a plane on a top face side of a heating chamber by advancing a feeding phase with a phase difference of 360°/2N clockwise or counterclockwise in turn.

The microwave power is distributed to microwave radiation elements arranged rotationally symmetrically around a reference line on a plane on a top face side of a heating chamber by advancing a feeding phase with a phase difference of 360°/2N clockwise or counterclockwise in turn.

A method of sensing at least one load parameter of a closed chamber by a sensing device by means of electromagnetic radiation is described, in which measurements of at least one measured variable are used. A first measurement is carried out when there is a first spatial distribution of the electric field generated by the electromagnetic radiation. At least a second measurement is carried out when there is a second spatial distribution of the electric field generated by the electromagnetic radiation, which differs from the first spatial distribution of the electric field. The at least two measurements are evaluated with regard to the at least one measured variable by means of a mathematical operation and/or mathematical transformation to obtain at least one evaluation variable from the measurement results by means of which the load parameter is determined by applying a pattern recognition which includes the at least one evaluation variable as an input variable, and/or a mathematical model which comprises the at least one evaluation variable and at least one training parameter that has been ascertained based on previous tests. Furthermore, a sensing device is described. Furthermore, the invention relates to a method of training, to a computer program, and to a computer-readable data carrier.