Abstract: An exposure device for exposing at least one object to an electromagnetic field, including a section of a waveguide or transmission line device including a guided electromagnetic wave, extending along a longitudinal axis, and including a hollow tubular electrical conductor inside which the electric field is established or plural electrical conductors between which the electric field is established. The device further includes a heterogeneous adaptation structure in mechanical contact with the electrical conductor or conductors, at least one extension element, and at least one housing for the object, contained in or positioned next to the extension element. The extension element is made from a material having a relative dielectric permittivity as close as possible to that of each object. The heterogeneous adaptation structure has a dimension, along the longitudinal axis, equal to a non-zero multiple of half-wavelengths of the electromagnetic wave to be propagated in the exposure device.

Abstract: An exposure device for exposing at least one object to an electromagnetic field, including a section of a waveguide or transmission line device including a guided electromagnetic wave, extending along a longitudinal axis, and including a hollow tubular electrical conductor inside which the electric field is established or plural electrical conductors between which the electric field is established. The device further includes a heterogeneous adaptation structure in mechanical contact with the electrical conductor or conductors, at least one extension element, and at least one housing for the object, contained in or positioned next to the extension element. The extension element is made from a material having a relative dielectric permittivity as close as possible to that of each object. The heterogeneous adaptation structure has a dimension, along the longitudinal axis, equal to a non-zero multiple of half-wavelengths of the electromagnetic wave to be propagated in the exposure device.

Abstract: A method for preparing an object to be tested, having a given relative permittivity, intended to be illuminated by an incident electromagnetic wave. The method includes: providing a part including a cavity for housing the object and at least one extension element made from a material having a relative permittivity that is preferably equal to that of the object, the extension element at least partially delimiting the cavity and extending to either side of the cavity in a passage direction of the cavity, over a length at least equal, on either side of the cavity, to one third of the length of the cavity in the passage direction, and placing the object in the cavity, such that the object is in contact with the extension element in the passage direction.