Abstract: An active antenna is disclosed including a passive portion of an antenna array extended at one end by a plate in which apertures are formed, at least one active assembly for transmitting radiofrequency RF waves, called assembly, through said apertures, each assembly including a first row of active modules facing apertures of the plate, a second row of active modules facing apertures of the plate and attached to the first row of active modules, a beam attached to the plate and held clamped between the first and second rows of active modules, a heat-transfer duct in contact with the first and second rows of active modules and jutting out on either side of said first and second rows of active modules.

Abstract: The invention concerns a tunable cavity resonator that comprises a resonator body (2, 3, 4) defining a cavity (5), a tuning plate (28) whose position with respect to the resonator body (2, 3, 4) is modifiable and which influences the resonance frequency (&ohgr;R) of the cavity resonator, and an adjustment device (22, 26) for mechanically changing the position of the tuning plate (28), which is characterized in that a conversion ratio mechanism (18, 20) couples the adjustment device (22, 26) to the tuning plate (28) in terms of movement and converts a linear excursion (&Dgr;x1) generated by the adjustment device (22, 26), at a predefined ratio (U), into a reduced linear excursion (&Dgr;x2) that acts on the tuning plate (28), the conversion ratio mechanism (18, 20) comprising a first spring element (20) whose end toward the adjustment device is deflectable with the linear excursion (&Dgr;x1) generated by the adjustment device (22, 26), and a second spring element (18) which impinges with an opposing force on th