Abstract: A bipolar transistor is manufactured by: forming a collector region; forming a first layer made of a material of a base region and an insulating second layer; forming a cavity reaching the collector region; forming a portion of the collector region and a portion of the base region in the cavity; forming an insulating fourth layer made of a same material as the insulating second layer in the periphery of the bottom of the cavity, the insulating fourth layer having a same thickness as the insulating second layer; forming an emitter region; and simultaneously removing the insulating second and a portion of the insulating fourth layer not covered by the emitter region.

Abstract: An electronic device includes an insulating first layer covering a second layer made of a doped semiconductor material. A cavity is formed to cross through the first layer and reach the second layer. Insulating spacers are forming against lateral walls of the cavity. A first doped semiconductor region fills the cavity. The first doped semiconductor region has a doping concentration decreasing from the second layer.

Abstract: A circuit includes at least one bipolar transistor and at least one variable capacitance diode. The circuit is fabricated using a method whereby the bipolar transistor and variable capacitance diode are jointly produced on a common substrate.

Abstract: A monopole wire-plate antenna that is reconfigurable in a frequency range of operation, comprising: a ground plane (1); a capacitive roof (2); a probe feed (3), which is electrically insulated from the ground plane (1), and which extends between the ground plane (1) and the capacitive roof (2) so as to electrically feed the capacitive roof (2); at least one shorting wire (4), which is arranged to electrically connect the capacitive roof (2) to the ground plane (1), and which is coated in a magneto-dielectric material (5) having a complex magnetic permeability, which varies as a function of a static magnetic field applied to the magneto-dielectric material (5).

Abstract: A monopole wire-plate antenna that is reconfigurable in a frequency range of operation, comprising: a ground plane (1); a capacitive roof (2); a probe feed (3), which is electrically insulated from the ground plane (1), and which extends between the ground plane (1) and the capacitive roof (2) so as to electrically feed the capacitive roof (2); at least one shorting wire (4), which is arranged to electrically connect the capacitive roof (2) to the ground plane (1), and which is coated in a magneto-dielectric material (5) having a complex magnetic permeability, which varies as a function of a static magnetic field applied to the magneto-dielectric material (5).