Abstract: The invention relates to a system (1) suitable for being inserted into an anatomical cavity (30), including: a support structure (10), an antenna (10), an assembly (22) of measuring devices, an assembly (26) for transmitting the data of the measurements carried out by the measuring devices (22), which is suitable for communicating with an external entity (E) by means of the antenna (10), and a device (24) for monitoring the assembly of measuring elements and the transmission assembly (26), said antenna consisting of the support structure (10), and the self-contained system being characterized in that the support structure (10) includes a non-conductive junction (20) supporting the assembly (22) of measuring devices, the transmission assembly (26), and/or the monitoring device (24), wherein the junction is suitable for producing an electrical discontinuity within the support structure (10) forming the antenna while mechanically supporting said support structure (10).

Abstract: In a microwave preamplifier of a Doppler radar system used for Earth observation, three pre-matched and self-biassed field effect microwave transistors are provided. By supplying these transistors by means of a voltage regulator, whose output voltage varies under the action of a control circuit, the gain of this pre-amplifier may be varied without modifying the standing wave ratio, thereby obtaining modulation of the microwave signal amplified by the amplifier. Thus, additional modulation may be obtained, speech modulation for example, on the transmission signal of an Earth observation Doppler radar system.

Abstract: In a microwave power transmitter for Doppler radars for terrestrial surveillance, use is made of four stages in series comprising first and second preamplifiers, and first and second power amplifiers. These stages are supplied by a group of separate voltage regulators. These regulators are controlled by a control circuit which makes it possible to cut off the stabilized voltage between instants of transmission, that is to say between microwave pulses of a radar signal. A feedback device makes it possible to stabilize the output level by causing variation of the gain of the first preamplifier by means of its supply voltage.

Abstract: A mixer comprising two microstrip plates, each having an earth plane, a dielectric layer and an etched layer. One of the etched layers carries the mixer ring and input guides. The outer etched layer carries the output guide and the tuning members. The plate are joined by their earth planes and the mixer diodes are placed in the holes connecting the two etched faces.