Abstract:
A method for manufacturing a wafer on which are formed resonators, each resonator including, above a semiconductor substrate, a stack of layers including, in the following order from the substrate surface: a Bragg mirror; a compensation layer made of a material having a temperature coefficient of the acoustic velocity of a sign opposite to that of all the other stack layers; and a piezoelectric resonator, the method including the successive steps of: a) depositing the compensation layer; and b) decreasing thickness inequalities of the compensation layer due to the deposition method, so that this layer has a same thickness to within better than 2%, and preferably to within better than 1%, at the level of each resonator.
Abstract:
An electronic device includes a transimpedance amplifier stage having an amplifier end stage of the class AB type and a preamplifier stage coupled between an output of a frequency transposition stage and an input of the amplifier end stage. A self-biased common-mode control stage is configured to bias the preamplifier stage. The preamplifier stage is formed by a differential amplifier with an active load that is biased in response to the self-biased common-mode control stage.
Abstract:
An integrated circuit chip cooling device includes a network of micropipes. A first pipe portion and a second pipe portion of the network are connected by at least one valve. The valve is formed of a bilayer strip. In response to change in temperature, the shape of the bilayer strip changes to move the valve from a substantially closed position to an open position. In one configuration, the change is irreversible. In another configuration, the change is reversible in response to an opposite change in temperature.
Abstract:
A reference voltage generation circuit, including a first current source in series with a first bipolar transistor; a second current source in series with a first resistor; a third current source in series with a second bipolar transistor, the third current source being assembled as a current mirror with the first current source; a second resistor between the base of the second bipolar transistor and the junction point between the current source and the first resistor; and a fourth current source in series with a third resistor, the junction point between the fourth current source and the third resistor defining a reference voltage terminal.
Abstract:
An electro-optic (E/O) device includes an asymmetric optical coupler having an input and first and second outputs, a first optical waveguide arm coupled to the first output of the first asymmetric optical coupler, and a second optical waveguide arm coupled to the second output of the first asymmetric optical coupler. At least one E/O amplitude modulator is coupled to at least one of the first and second optical waveguide arms. An optical combiner is coupled to the first and second optical waveguide arms downstream from the at least one E/O amplitude modulator.
Abstract:
A power management circuit including, between a first terminal intended to be connected to an electric power generation source and a second terminal intended to be connected to a load to be powered, a linear regulator and a circuit capable of activating the linear regulator when the power supplied by said source is greater than a first threshold.
Abstract:
An overvoltage protection component may be in a SOI layer, a portion of the SOI layer forming the core of an optical waveguide. This component may be made of semiconductor regions of different doping types and/or levels, at least one of these regions corresponding to at least a portion of the waveguide core.
Abstract:
An integrated structure includes a support supporting at least one chip and a heat dissipating housing, attached to the chip. The housing is thermally conductive and has a thermal expansion compatible with the chip. The housing may further including closed cavities filled with a phase change material.
Abstract:
A photodetector including a photoelectric conversion structure made of a semiconductor material and, on a light-receiving surface of the conversion structure, a stack of first and second diffractive elements, the second element being above the first element, wherein: the first element includes at least one pad made of a material having an optical index n1, laterally surrounded with a region made of a material having an optical index n2 different from n1; the second element includes at least one pad made of a material having an optical index n3, laterally surrounded with a region made of a material having an optical index n4 different from n3; the pads of the first and second elements are substantially vertically aligned; and optical index differences n1−n2 and n3−n4 have opposite signs.
Abstract:
A method of manufacturing an integrated circuit including photonic components on a silicon layer and a laser made of a III-V group material includes providing the silicon layer positioned on a first insulating layer that is positioned on a support. First trenches are etched through the silicon layer and stop on the first insulating layer, and the first trenches are covered with a silicon nitride layer. Second trenches are etched through a portion of the silicon layer, and the first and second trenches are filled with silicon oxide, which are planarized. The method further includes removing the support and the first insulating layer, and bonding a wafer including a III-V group heterostructure on the rear surface of the silicon layer.