Abstract: A predistortion linearization device (D) produces gain and phase expansions making it possible to compensate for the gain compression and phase variation of a power amplifier. This device (D) also allows the conventional adjustment of amplitude, the adjustment of the form of the gain and phase expansions as a function of a microwave input signal (Se).

Abstract: A predistortion linearization device (D) produces gain and phase expansions making it possible to compensate for the gain compression and phase variation of a power amplifier. This device (D) also allows the conventional adjustment of amplitude, the adjustment of the form of the gain and phase expansions as a function of a microwave input signal (Se).

Abstract: A system including a first station (1) known as a beacon and at least one second station (2) known as a badge, each station having a transmission channel with an antenna and a reception channel with an antenna.To allow multiplex exchanges, using simultaneous transmission and reception, the two antennas (6, 11) (13, 15) in any given station are decoupled by cross-polarization but antennas which communicate with each other (6, 13) (11, 15) have compatible polarization.Applications to identification systems using microwave transmission.

Abstract: In order to increase the sensitivity and range of a system for the exchange of data by microwaves between a fixed station, or reader, and a mobile station, or badge, the modem of the badge includes an oscillator. A single transistor works, under a first bias, as a detector of the wave transmitted by the reader and demodulates this wave, and then, under a second bias, it works as an oscillator and modulates the response transmitted by the badge. Applications to the exchange of data at a distance.

Abstract: This active antenna is incorporated in the terminal station of a system for data exchange with a central station, by the modulation of a microwave carrier. The terminal station is of the chip card type. The modem of the active antenna is constituted by a transistor, the bias current of which is switched over from a low value at demodulation to a high value at modulation. The switch-over is obtained by a circuit with three resistors (R.sub.d, R.sub.gd, R.sub.g), which themselves have their values switched over by two transistors parallel connected with the resistors, these transistors being controlled by two signals emitted by the control circuit of the terminal station. The active antenna can be applied to long-distance data exchange, for example in the remote management of toll-charge systems, remote cash dispensing, localization of moving bodies etc.

Abstract: The disclosure relates to the field of data exchange by microwaves between a fixed station, or reader, and a mobile station, or badge. To achieve economy in the energy consumption of the badge, which has a "chip card" format, its input circuit or modem connected to the antenna does not transmit the modulated signal towards the reader. It reflects, in varying degrees, the carrier transmitted by the reader. The modulation of the reflection coefficient of the antenna is obtained by variation of the gate-source junction capacitance, which it itself related to the variation of the gate-source bias voltage of the input transistor of the modem. Application to remote-control toll-gates, remote money transactions and security checks.

Abstract: A device fixed on a measuring instrument provides access to the terminals of a microwave component in order to measure scattering, noise or output power parameters. In order to minimize the length of connections between the access lines of the device and the input and output terminals of the component to be measured, two access blocks which carry the access lines are positionally adjustable with respect to the component to be measured in such a manner as to permit two degrees of freedom in relative-spacing displacement and in lateral translational displacement. Irrespective of the type of component to be measured (chip, package, or hybrid circuit), the component is carried by an insert block placed between the two access blocks and having dimensions equal to those of the component.