Abstract: The aerial comprises an element (20) capable of radiating or receiving an electromagnetic field, a conductive plane (22), and an anisotropic composite 24, formed by a stack of alternate ferromagnetic and electrically insulated layers. These layers or film are perpendicular to the conductive plane and to the electrical component (E) of the radiated or received field.

Abstract: The aerial comprises an element (20) capable of radiating or receiving an electromagnetic field, a conductive plane (22), and an anisotropic composite 24, formed by a stack of alternate ferromagnetic and electrically insulated layers. These layers or film are perpendicular to the conductive plane and to the electrical component (E) of the radiated or received field.

Abstract: A switching device for adjusting the impedance of a self-inductance (3) forming part for example of the radiator of a VHF/UHF antenna for aircraft switchable by short-circuiting a part of the self-inductance. A PIN diode (12) is raised to a blocking or a transmitting voltage in response to control signals which are transmitted thereto by an optical link (8). Preferably the optical signals are transmitted to a hybrid opto-electronic circuit, which renders the PIN diode operative in conjunction with insulated conductors (11, 13) plated on the self-inductance and raised to the desired voltage.

Abstract: This invention concerns an antenna switchable between the VHF and UHF frequency bands. This antenna incorporates a capacitive element, disposed at a specified distance from a reflecting surface mounted on the body of the vehicle. For VHF, tuning is obtained by a fixed self-inductance in parallel and a variable self-inductance in series with the capacitive element. The latter comprises various sections which can be short-circuited by switches. For UHF, the variable self-inductance is totally short-circuited and the fixed self-inductance is disconnected by a switch; then, plates form, with the reflecting surface and the capacitative element, a "manchette" antenna. This switchable antenna can in particular be mounted on an airplane.