摘要:
The disclosure relates to the making of the source and drain access regions of a field-effect transistor, these two regions being differentiated. The control region is defined by means of a three-layer mask of metal, resin and metal. A resin mask protects the drain access region, thus enabling the implantation of the source access region. After the dissolving of the resins, the drain access region is implanted.
摘要:
The disclosure relates to a compact optical device, intended for use in a night vision telescope, that includes an objective, a standard light intensifier that rotates the image through 180° between its entry and its exit, an eyepiece, and four optical deflections, one in the objective and three in the eyepiece. The eyepiece, producing a single intermediate image between its entry and its exit, includes a combiner whose deflection angle α depends on its optical index n and the half-field θ of the device. The field width of the device is at least 40°. The invention is applicable notably to night vision binoculars for aircraft or helicopter pilots.
摘要:
A process for the separation of static and dynamic components of a sequence of images separated in time and taken under the same conditions. The process includes recording a first intensity of a first pixel in at least one area in the sequence of images, recording subsequent intensities for identical pixels to the first pixel in subsequent recorded images, and using pixel intensity sort criteria on intensity changes between the first intensity and the subsequent intensities to discriminate in the subsequent recorded images pixels showing minimal intensity changes from pixels showing larger intensity changes as the sequence process. The process includes forming from the pixels showing minimal intensity changes a part of the static component of the sequence of images.
摘要:
Disclosed is an apparatus for measuring a bit error rate (BER) in an orthogonal frequency division multiplexing (OFDM) communication system. A transmitter includes a pilot pattern inserter for inserting a first reference pilot pattern in subchannels of input data, and an OFDM modulator for OFDM-modulating the reference pilot pattern-inserted transmission data. A receiver includes a pilot pattern detector for OFDM-demodulating a data symbol received in a frame unit and detecting only a pilot pattern, and a BER operator for comparing the demodulated pilot pattern with a second reference pilot pattern, detecting and accumulating the number of pilot errors, and measuring a bit error rate by dividing the accumulated number of the pilot errors by the number of total received pilot patterns.
摘要:
The disclosure relates to an optical disk of the type including at least one spiral track on which information marks are written in sectors whose addresses are substantially sequential along the track, wherein said disk includes a copy protection zone (PZ) comprising two parts of equal size each including a series of sectors designated by identical addresses on each of the two parts, the data written in this zone being shared between the sectors of the two parts, each sector of the zone also carrying an identifier (D1, D2) characteristic of the part to which the sector belongs, and specific protection data to enable verification of the presence and constitution of said protection zone (PZ) and to enable use of the data written in this zone, at least part of said specific protection data being recorded on said disk. The invention is notably applicable to anti-piracy protection of CD-ROM and DVD-ROM type disks.
摘要:
The disclosure pertains to methods of fast exploration in azimuth by a surveillance radar antenna and to radars implementing such methods. The method consists in driving, at slow speed, an antenna comprising two elementary electronic scanning antennas installed back to back, simultaneously controlling the electronic aiming of each elementary electronic scanning antenna, switching over the microwave signal sent alternatively between the two elementary electronic scanning antennas and, before each rotation of the radar beam, initializing the electronic aiming of each elementary electronic scanning antenna at a determined angle nulli. The radar comprises an antenna with two elementary electronic scanning antennas and an aiming computer. Application especially to a sea patrol radar.
摘要:
An optical system for presenting an image to a user. The system includes an image source and an optical channel transmitting the image to the user's eye. It also includes an illumination of the ocular fundus and an imaging of the illuminated ocular fundus, both using part of the optical channel. The system enables an analysis of the eye retina observing an image. It also enables depending on the eye position, an adaptation of the visual image presented. If the system is partially mounted in a headset, it enables the presentation of the image to a mobile user.
摘要:
The disclosure relates to a bispectral electromagnetic wave detector including at least one first and one second overlaid plane active detector elements separated by a common layer, said first and second detector elements being sensitive to the different wavelengths; a first means of connection connected in common to said first and second detector elements, a second means of connection connected to said first detector element, and a third means of connection connected to said second detector element; means for applying successively a control voltage to each means of connection; and means connected to said first means of connection to detect a photoconduction current each time a control voltage is applied. The invention is used in applications requiring detection of electromagnetic waves in two bands of different wavelengths.
摘要:
A method for controlling the navigation of a towed linear acoustic antenna. Birds equipped with variable-incidence wings are fixed onto the antenna. Through a differential action, the wings allow the birds to be turned about the longitudinal axis of the antenna so that a hydrodynamic force oriented in any given direction about the longitudinal axis of the antenna is obtained. Power and control signals are transmitted between the antenna and the bird by rotary transformers. The bird is fixed to the antenna by a bore closed by a cover. The bird can be detached automatically as the antenna is raised so that the antenna can be wound freely onto a drum. This method allows the full control of the deformation, immersion and heading of the antenna.
摘要:
Present-day single or multiple fractional phase-locked loop frequency synthesizers are not phase coherent for they use a digital accumulator modulo a number P with a variable increment K, whose state is a function of the history of the change in values that have been imposed on the increment. This lack of phase coherence rules out the use of these synthesizers in certain fields such as that of Doppler radars. A novel type of single or multiple fractional phase-locked loop frequency synthesizer that is coherent in phase is proposed herein. This type of synthesizer comprises one or more counters with an increment of one, having their rate set by the reference oscillator of the synthesizer and being used in phase memories to enable changes in the increment or increments following a change in the fractional division ratio at instants that are synchronous with the reference oscillator.