Thomson-csf

Thomson Hybrides Et Microondes

Jean Stevance

Gerard Cachier

Ronald Funck

Narquise Mamodaly

Georges Lleti

Edmond Klein

A negative-resistance diode oscillator tuned by a varactor as applicable to frequency-modulated transmitters or to receiver oscillators operating within the 56-100 GHz frequency band is integrated in a waveguide. The diode is encapsulated in a capped package and mounted on a ground-connected base. A coupling capacitor is fixed on the metallic cap of the package. A varactor having beam-lead connections is mounted as a bridge between the capacitor and a ground-connected metallic stud. The bias voltages are brought in the plane of the waveguide by means of two wires and two capacitors housed within orifices formed through the waveguide walls.

Microwave oscillator integrated in a waveguide

A microwave oscillator integrated in a waveguide includes a negative-resistance diode encapsulated in a capped micromodule, a capacitor fixed on the cap, a resonator fixed on the capacitor and a metallic strip fixed on the capacitor and on a grounding stud. The metallic strip constitutes a device for coupling the diode with the auxiliary load and with the resonator. Outside the resonance frequency of the resonator, no oscillation is possible since the diode is in that case loaded by a low resistance and is not capable of oscillating. The dielectric resonator is the only element which resonates, thus endowing the oscillator with high stability.

A slot-line for a microwave device in which is mounted at least one diode connected in parallel between two metallic strips of the slot. At high frequencies (18 to 200 GHz), the inductance L of the diode connections presents a not-negligible impedance which makes it difficult to use the diode. The device in accordance with the invention comprises a slot-line reentrant circuit which provides compensation for the diode inductance and is constituted by a metallic section which is coplanar with the line and connected in series with the diode. The compensating section is short-circuited or open-circuited with respect to the metallic strip in which it is reentrant. The electrical length of the compensating section is adjustable by means of wire, conductive varnish or metal pads.

Slot-line switching and limiting device for operation at microwave

A millimeter wave source, wherein an active diode, for example an avalanche diode, forming the emitter of the source is arranged opposite to a variable capacity diode, so as to have the source frequency-modulated by varying the biassing voltage of the variable capacity diode. In this source, each diode is mounted in a 'module' comprising a thermally and electrically conductive support onto which a diode is in contact by one of its electrodes, the other electrode being in contact with a metallization deposited on a thick layer of dielectric material surrounding the diode. Owing to the capacitive coupling between the metallizations of both modules, the source can be frequency-modulated with a high efficiency.

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Aulnay sous Bois, France

Jean Stevance