摘要:
It is proposed that passive wireless transponder systems used in the context of procedures for access identification be provided with signaling that can be perceived by human beings. This also makes it possible to detect that a relay attack, which is difficult to prevent, is being carried out. Attention is also drawn to other types of manipulative interference with the communication and to certain problems with the high-frequency transmission. By the employment of comparatively inexpensive and highly reliable means, this near-simultaneous perception of an identifying process for access purposes produces a very effective reduction in such threats to the security of the system. Other simple measures may have an advantageous effect in connection therewith. The signaling may also assist an ergonomic process. For example, an automobile entry or access system that is not specifically actuated, referred to as a passive keyless entry system, may be improved.
摘要:
The invention relates to an antenna comprising a dielectric substrate (1) and two resonant printed wiring structures, more particularly for use in high-frequency and microwave domain. On an end face of the structure (2) is arranged along a first edge and on an opposite, second edge of the same end face a second printed wiring structure (3). The arrangement of the printed wiring structures provides that resonances are developed which make the use of the proposed antennas in the four separate GPS, DCS/PCS, UMTS and Bluetooth applications possible.
摘要:
A method and device for operating a device for high-voltage switching for driving capacitive loads, having a first and a second input terminal (11, 12) for applying a high voltage supply, such that a higher potential of the high-voltage supply may be applied to the first input terminal (11) and a lower potential may be applied to the second input terminal (12); a first and a second switch (S1, S2), connected in series between the first and the second input terminal (11, 12); a first and a second clamping diode (D3, D4), connected in series and in the same blocking direction between the first input terminal and the second input terminal, such that the first second clamping diode block with respect to the applied high voltage; a storage inductor Ls, which is connected with one of its terminals to a connecting point (13) of the both switches and with another terminal to a connecting point (14) of the both clamping diodes; and an output terminal (15) for connecting a capacitive load Cl, which output terminal is connected with the connecting point (14) of the both clamping diodes (D3, D4). The method comprises starting with both switches (S1, S2) open; closing of the first switch (S1) after a first predetermined time; opening (ST3) of the first switch (S1) after a second predetermined time; closing (ST4) of the second switch (S2), after arriving a zero voltage over the second switch.
摘要:
An x-ray tube disclosed here in includes an emitter arranged to emit electrons on to a focal spot on a rotatable anode. The x-ray tube also includes a hollow tube arranged to receive electromagnetic radiation from the focal spot at one end of the hollow tube and transmit it to another end. The x-ray tube also includes two or more sensors arranged to detect the electromagnetic radiation through the hollow tube.
摘要:
The invention relates to a non-reciprocal component comprising: a ferrite substrate having a first side and an opposing second side located on a ground layer, a first metal line and a second metal line are located on the ferrite substrate in parallel to each other. To provide a non-reciprocal component having small dimensions and which could be integrated. The ferrite substrate is magnetized parallel to the metal lines and each of the metal lines is running at least from one side of the ferrite substrate to the other side and back forming thereby at least one meander loop, wherein the loops are interlaced to each other and the metal lines are isolated in an area of the loop.
摘要:
A computed tomography reconstruction method includes concurrently emitting radiation from at least two x-ray sources (14), switching the output state of each of the at least two x-ray sources (14) within a plurality of respective cross scatter sampling intervals (50, 52, 54, 56) and detecting with a corresponding one of the sets of detectors (24) cross scatter radiation emitted by the other at least two x-ray sources (14), wherein the cross scatter sampling intervals are angularly spaced over a plurality of frames to allow the at least two x-ray sources (14) to concurrently emit radiation throughout at least one frame, deriving scatter correction data for each set of detectors (24) from corresponding cross scatter samples, scatter correcting the projection data with corresponding scatter correction data, and reconstructing the scatter corrected projection data to generate at least one image.
摘要:
For the generation of multiple-energy X-ray radiation, an X-ray tube (10) for generating multiple-energy X-ray radiation includes an anode (12) and a filter (14). At least a first (16) and a second focal spot position (18) are offset from each other in an offset direction (20) transverse to an X-ray radiation projection direction. The filter includes a first plurality (22) of first portions (24) with first filtering characteristics for X-ray radiation and a second plurality (26) of second portions (28) with second filtering characteristics for X-ray radiation. The filter is a directional filter adapted in a such a way that at least a first X-ray beam (30) emanating from the first focal spot position at least partly passes through the filter unit via the first portions, and a second X-ray beam (32) emanating from the second focal spot position passes obliquely through the first and the second portions when passing through the filter unit.
摘要:
The present invention relates to X-ray generating technology in general. Providing an electron collecting element of an X-ray generating device statically may allow for the manufacture of X-ray systems with reduced moving parts and actuating parts, possibly reducing manufacturing costs and sources for failure. Consequently, an electron collecting element with increased thermal loadability is presented. According to the present invention, an electron collecting element (28) is provided, comprising a surface element (22) and a heat conducting element (26). The heat conducting element (26) comprises a first thermal conductivity in a first direction and at least a second thermal conductivity in at least a second direction. The first thermal conductivity is greater than the second thermal conductivity. The first direction is substantially perpendicular to the surface element (22).
摘要:
This invention relates to high power X-ray sources, in particular to those equipped with a rotating X-ray anode capable of delivering a higher short time peak power than conventional rotating x-ray anodes. This invention can overcome the thermal limitation of peak power by allowing fast rotation of the anode and by introducing a lightweight material with high thermal conductivity in the region adjacent to the focal track material. The fast rotation can be provided by using sections of the rotating anode disk made of anisotropic high specific strength materials with high thermal stability that can be specifically adapted to the high stresses of anode operation. Uses include high speed image acquisition for X-ray imaging, for example, of moving objects in real-time such as in medical radiography.
摘要:
Device and method for synchronously switching activating a first and second charge accumulation section (31, 32) for a duration of a first and second predetermined sub-frame and a first and second X-ray source until lapse of a predetermined time frame for each of the first and second charge accumulation section (31, 32) for the accumulation of a plurality of temporally distributed partial charges according to an origin of a respective one of the plurality of spatially distributed X-ray sources so as to establish a specific relation between the focal spot position and a rule for accumulating the respective partial measurements, e.g. temporally distributed partial charges, belonging to the same focal spot positions, and to keep the focal spot temperature low by only activating the focal spot for a limited time according to a sub-frame.