425 results about "High frequency radiation" patented technology

The invention relates to an MR imaging method for representing and determining the position of a medical device inserted in an examination object, and to a medical device used in the method. In accordance with the invention, the device (11) comprises at least one passive oscillating circuit with an inductor (2a, 2b) and a capacitor (3a, 3b). The resonance frequency of this circuit substantially corresponds to the resonance frequency of the injected high-frequency radiation from the MR system. In this way, in a locally limited area situated inside or around the device, a modified signal answer is generated which is represented with spatial resolution.

The invention provides a plasma processing apparatus aimed at suppressing the corrosion caused by reactive gas and heavy-metal contamination caused by plasma damage of components constituting the high-frequency electrode and gas supply unit. The plasma processing apparatus comprises a processing chamber 1 for subjecting a processing substrate 4 to plasma processing, gas supply means 17, 16 and 11 for feeding gas to the processing chamber 1, and an antenna electrode 10 for supplying high-frequency radiation for discharging the gas to generate plasma, wherein the gas supply means includes a gas shower plate 11 having gas discharge holes on the surface exposed to plasma, and a portion of or a whole surface of the conductor 10 exposed to gas constituting the antenna-electrode side of the gas supply means is subjected to ceramic spraying containing no heavy metal to form a protecting film 12.

A suture member for joining the first and second sides of a cut in body tissue, such suture member having an elongated body member in one embodiment with a needle and thread member disposed at one end thereof and with externally activatable adhesive disposed on the suture member. The adhesive is activated by application of high-frequency radiation directed through the body tissue to retain the suture member securely in the body tissue.

A plasma detector system may include a high frequency generator arranged to send incident electromagnetic radiation through a plasma chamber of a plasma system; and a high frequency detection system arranged to detect signal intensity of high frequency radiation sent from the high frequency generator and transmitted through the plasma chamber.

Combined positron emission tomography and magnetic resonance tomography unit for imaging an examination object in an examination space, comprising a positron emission tomography unit that has a unit part assigned to the examination space, and a first evaluation unit for evaluating the electric signals for a positron emission tomography image of the examination object. The unit part in this case comprises a gamma ray detector with an assigned electronics unit. Furthermore, the combined unit comprises a magnetic resonance tomography unit and a second evaluation unit for evaluating the magnetic resonance signals for a magnetic resonance image of the examination object. The magnetic resonance unit in this case has a high frequency antenna device as well as a gradient coil system, the high frequency antenna device being arranged nearer to the examination space than the gradient coil system, as well as a high frequency shield arranged between the gradient coil system and the high frequency antenna device. The positron emission tomography unit part is arranged in this case between the high frequency shield and the high frequency antenna device, and is provided, at least on the side facing the high frequency antenna device, with a shielding cover that is caused by the high frequency antenna device and is opaque to high frequency radiation.

An implantable medical device includes a detector for detecting the presence of a magnetic field, where the presence of the magnetic field is detected in response to the strength of the magnetic field exceeding a first preselected magnetic field threshold. The device further includes a processor for adjusting a stimulation rate provided by the implantable medical device in response to determining that the strength of the detected magnetic field exceeds a second preselected magnetic field threshold. The second preselected magnetic field threshold is greater than the first preselected magnetic field threshold. In another embodiment, the implantable device includes a detector for detecting the presence of a high frequency (HF) radiation interference signal and a processor for adjusting a stimulation rate provided by the implantable medical device in response to determining that the strength of the detected HF radiation interference signal exceeds a preselected HF radiation threshold.

A positron emission tomography unit (PET), having a unit part assigned to an examination space and a first evaluation unit, is combined with a magnetic resonance tomography unit (MRT). The unit part of the PRT includes at least two gamma ray detector units with in each case an assigned electronics unit. The MRT includes a second evaluation unit, a gradient coil system and a high frequency antenna device formed as a stripline antenna device having at least two conductors. The high frequency antenna device is arranged nearer to the examination space than the gradient coil system with a high frequency shield between the gradient coil system and the high frequency antenna device. Each conductor of the stripline antenna device respectively includes a gamma ray detector unit with an assigned electronics unit. The conductors of the stripline antenna device are configured for the respective gamma ray detector units and their assigned electronics units as shielding covers that are caused by the high frequency antenna device and are opaque to high frequency radiation. An examination object in the examination space can be imaged by the combined positron emission tomography and magnetic resonance tomography unit.

An assembly for shielding an implanted medical device from the effects of high-frequency radiation and for emitting magnetic resonance signals during magnetic resonance imaging. The assembly includes an implanted medical device and a magnetic shield comprised of nanomagnetic material disposed between the medical device and the high-frequency radiation. In one embodiment, the magnetic resonance signals are detected by a receiver, which is thus able to locate the implanted medical device within a biological organism.

The invention, suitable for the field of mobile communication base station antenna, discloses a wideband double frequency mobile communication base station antenna, which comprises a low frequency radiation unit array, a high frequency radiation unit array, a low frequency feed network, a high frequency feed network and a reflection plate. The low frequency unit enhances bandwidth by introducing parasitic radiation patch. Tail ends of two pairs of radiation arms of the high frequency radiation unit are bent, the high frequency radiation unit array is nested in blank region remained by the lowfrequency radiation unit, and the radiation unit array is fixed axially to the reflection plate. The high and low frequency radiation units are etched on the same surface of medium base plate of antenna radiation body, and L-shaped coupled micro-strip feed lines are etched on the other surface of the medium base plate of the antenna radiation body. High and low frequency micro-strip power dividers disposed on the reflection plate are connected with the high and low frequency radiation units respectively through a coaxial line, each signal is input to the radiation unit corresponding to each array in uniform amplitude and constant phase way, and such symmetrical feed mechanism ensures that the antenna can obtain good directional diagram property.

The invention discloses an ultra wideband multi-band dual-polarized antenna, which comprises a reflection board, at least one low-frequency radiation unit and at least one high-frequency radiation unit, wherein the low-frequency radiation units and the high-frequency radiation units are arranged on the reflection board; the high-frequency radiation units are adjacent to the low-frequency radiation units; and each high-frequency radiation unit comprises a high-frequency vibrator insulated from the top surface of the reflection board and a bowl-shaped radiator arranged on the periphery of the high-frequency vibrator. According to the ultra wideband multi-band dual-polarized antenna, by the high-frequency radiation units, an operating frequency range is widened, and meanwhile, coupling with the low-frequency radiation units can be effectively reduced; and by the low-frequency radiation units, an operating frequency range is widened, and meanwhile, the radiation efficiency can be effectively improved. Therefore, the bandwidths of the low-frequency operating frequency range and the high-frequency operating frequency range can be greatly increased, and the ultra wideband multi-band dual-polarized antenna has the advantages of small frontal area and compact structure.

The invention relates to the technical field of radar detection, in particular to multi-station lightning VHF (very high frequency) radiation source three-dimensional positioning method and system. The method includes: acquiring elevation of lighting arriving a single station through double antenna arrays vertically disposed at the single station, establishing an equation set by three or more single-station elevations, and calculating to obtain an occurrence three-dimensional spatial position of a flashing radiation source. The invention provides the lightning VHF radiation source three-dimensional positioning system based on the method. The system comprises at least three single stations and a data processing center. Each single station comprises a radiofrequency antenna array, a GPS (global positioning system) clock module, and a signal acquisition and processing module. Compared with the like prior arts, the method and system enable the detection range of the single station to be effectively enlarged, the antenna arrays and the data acquisition equipment to be simpler, and equipment cost and erection cost to be lower. The method and system are capable of detecting three-dimensional spatial evolution characteristics of lightning in large range, have the functions of early lightning warning, estimation on lightning danger area and fierce thunderstorm danger and the like, and provide effective information for lightning disaster prevention and severe convection weather warning.

The invention relates to a multi-frequency-band array antenna compact in structure. The multi-frequency-band array antenna comprises a metal reflective board, a low-frequency radiation unit working in low frequency bands and a high-frequency radiation unit working in high frequency bands, and the low-frequency radiation unit and the high-frequency radiation unit are arranged on the metal reflective board. The low-frequency radiation unit and the high-frequency radiation unit are arranged on the metal reflective board in a nested mode, and the orthographic projection of the low-frequency radiation unit and the orthographic projection of the high-frequency radiation unit do not coincide. The low-frequency radiation unit is formed by connecting a horizontal vibrator and a vertical vibrator with a power divider feed network and is flexible in structure, and a distance and other parameters can be flexibly configured according to practical application requirements. Due to the adoption of the structure, circuit network losses are few, the radiation characteristic stability of the multi-frequency-band array antenna within an ultra wide band range can be maintained, 2G, 3G and 4G LTE systems in mobile communication are compatible, the number of antennas used in a base station can be reduced, station distribution cost can be lowered, and operation and maintenance cost can also be lowered.

A method for controlling a high-frequency radiator includes the steps of: (a) applying a high-frequency radiation through the solid-state oscillator and the antenna; (b) sensing part of the high-frequency radiation returned from the antenna to the solid-state oscillator; (c) adjusting radiation / propagation conditions for the high-frequency radiation on the basis of the sensed results in the step (b), the high-frequency radiation propagating from the solid-state oscillator to the antenna; and (d) after the step (c), applying the high-frequency radiation through the solid-state oscillator and the antenna to a target object. In the step (c), the oscillation frequency of the solid-state oscillator, the power of the high-frequency radiation applied by the solid-state oscillator, the power supply voltage supplied to the solid-state oscillator, the impedance match between the output impedance of the solid-state oscillator and the impedance of the antenna, or any other condition is changed.

A broadband dual-polarized antenna comprises a feeding panel, a dielectric panel, a radiant panel and a director, wherein the radiant panel comprises a +45-degree polarization oscillator and a -45-degree polarization oscillator which is orthogonal to the +45-degree polarization oscillator, and each polarization oscillator comprises two radiant sub-panels; the feeding panel comprises a first feeding sub-panel and a second feeding sub-panel, the dielectric panel is supported on a reflecting panel through coaxial feeders, the feeding panel and the radiant panel are printed on the upper layer and the lower layer of the dielectric panel, the feeding sub-panels of the feeding panel are connected with inner conductors of the coaxial feeders respectively, the first feeding sub-panel is aligned to one radiant sub-panel of the +45-degree polarization oscillator so as to conduct coupled feeding, the second feeding sub-panel is aligned to one radiant sub-panel of the -45-degree polarization oscillator so as to conduct coupled feeding, and outer conductors of the coaxial feeders are connected with the other two radiant sub-panels respectively so as to conduct feeding; the director is arranged above the feeding panel, the feeding panel is used for controlling a high-frequency resonance point, the radiant panel is used for controlling a low-frequency resonance point, and the director is used for controlling a high frequency radiation pattern. The broadband dual-polarized antenna improves broadband matching performance.

The invention provides an ultra-wide-band horn antenna comprising a mode conversion feedback cavity part, a coaxial line excitation part, and a double-ridged horn part. The mode conversion feedback cavity part includes a feedback cavity, a short-circuit board, a cross bump, a wedge, a slope, an upper ridge, and a lower ridge. Through a metal sleeve, the short-circuit board, the slope, the wedge, a horn narrow side wall and other structures, the antenna has low voltage standing wave ratio and good radiation pattern. In the whole working frequency band of the antenna, the standing wave of the antenna is effectively reduced, and the gain of the antenna is improved. The horn narrow side wall is composed of a position-adjustable metal gate, so that the horn antenna has good low-frequency characteristic, the high-frequency radiation pattern is not deteriorated, and satisfactory impedance matching and radiation characteristics are obtained in the wide band from 0.8GHZ to 20GHZ. The ultra-wide-band horn antenna has the advantages of large power capacity, wide frequency band, high gain, and good directivity.

An assembly for shielding an implanted medical device from the effects of high-frequency radiation and for emitting magnetic resonance signals during magnetic resonance imaging. The assembly includes an implanted medical device and a magnetic shield comprised of nanomagnetic material disposed between the medical device and the high-frequency radiation. In one embodiment, the magnetic resonance signals are detected by a receiver, which is thus able to locate the implanted medical device within a biological organism.

A multi-frequency array antenna, includes a reflective metal plate, a low-frequency radiation column element which is arranged on the reflective metal plate and operating in a first frequency band range, and a high-frequency radiation column element operating in a second frequency band range. The low-frequency radiation column element comprises several low-frequency radiation units arranged at an equal first distance in the axial direction of a first reference axis. The high-frequency radiation column element comprises several high-frequency radiation units arranged at an equal second distance in the axial direction of the first reference axis. The first distance is 2.5 times the second distance. At least one of the low-frequency radiation units is nested with one high-frequency radiation unit locationally corresponding thereto, and at least one of the low-frequency radiation units is axially located between two adjacent high-frequency radiation units close to the low-frequency radiation unit.

The invention provides a multi-frequency base station antenna for eliminating coupling resonance. The multi-frequency base station antenna comprises a reflecting plate, a first low-frequency radiationarray, a second low-frequency radiation array and a first high-frequency radiation array, wherein the first low-frequency radiation array and the second low-frequency radiation array are arranged onthe reflecting plate, are parallel to each other and are arranged on the same radiation surface, the first high-frequency radiation array is arranged between the first low-frequency radiation array and the second low-frequency radiation array, the first low-frequency radiation array and the second low-frequency radiation array respectively comprises a plurality of low-frequency radiation units, the first high-frequency radiation array comprises a plurality of first high-frequency radiation arrays, the multi-frequency base station antenna also comprises isolation strips, and the isolation strips are parallel to the reflecting plate, are insulated with the reflecting plate, extend along central axes of the first low-frequency radiation array and the second low-frequency radiation array and are arranged between radiation surfaces of the first high-frequency radiation units and radiation surfaces of the first low-frequency radiation units and the second low-frequency radiation units. By the multi-frequency base station antenna, coupling among the arrays is reduced, and the technical effects of improving the isolation among the arrays and reducing resonances among the arrays are achieved.

The invention provides an indoor dual-polarization omnibearing ceiling antenna which comprises a perpendicular polarization antenna body and a horizontal polarization antenna body arranged above the perpendicular polarization antenna body. The horizontal polarization antenna body comprises a dielectric slab, two axisymmetric annular arrays located on the top face and the bottom face of the dielectric slab, and a first cable. The annular arrays comprise low-frequency radiation unit sets and high-frequency radiation unit sets located on the inner sides of the low-frequency radiation unit sets. Each low-frequency radiation unit in each low-frequency radiation unit set is connected with a high-frequency radiation unit at the corresponding position in the corresponding high-frequency radiation unit set through a circuit, so that a plurality of subarrays are formed, and the subarrays on the same side of the dielectric slab are connected in parallel. The subarrays on the top face of the dielectric slab are connected in parallel and then connected with an inner conductor of the first cable, and the subarrays on the bottom face of the dielectric slab are connected in parallel and then connected with an outer conductor of the first cable. According to the indoor dual-polarization omnibearing ceiling antenna, a uniform current loop is simulated, so that omnibearing radiation is achieved, and thus working frequency of the perpendicular polarization antenna body coincides with that of the horizontal polarization antenna body.

The invention provides a low-frequency radiation unit. The low-frequency radiation unit comprises a radiator, a feed balun and a bottom plate, the radiator comprises two pairs of annular radiation arms which are orthogonally distributed, each annular radiation arm is divided into a plurality of wide line segments, and every two adjacent wide line segments are connected through a bent line. The feed balun is of an orthogonal structure, the top of the feed balun is connected with the radiator, and the bottom of the feed balun is connected with the bottom plate. The invention also provides a basestation antenna comprising the low-frequency radiation unit. Therefore, the low-frequency radiation has a space decoupling function, the influence of the low-frequency radiation unit on the high-frequency radiation performance can be effectively reduced when the high-frequency antenna and the low-frequency antenna are nested to form an array, and the miniaturization of the antenna size can be realized.

The invention relates to a multi-band array antenna compact in structure. The multi-band array antenna compact in structure comprises a metal reflecting board, a low frequency radiation unit working in a low frequency band and a high frequency radiation unit working in a high frequency band. The low frequency radiation unit and the high frequency radiation unit are arranged on the metal reflecting board in a nested mode, and the orthographic projections of the low frequency radiation unit and the high frequency radiation unit are not overlapped. The low frequency radiation unit is formed by connecting a horizontal oscillator, a vertical oscillator and a feed network. A low frequency oscillator is flexible in structure, and parameters such as separation distances can be flexibly configured according to practical application requirements. By the adoption of the structure, the stability of radiation characteristics of multi-band frequency array antennas in an ultra wide band range can be kept, the multi-band array antenna compact in structure is compatible with all 2G, 3G and 4G LTE standards in mobile communication, the number of antennas used by a base station is reduced, station distribution cost is reduced, and operation maintenance cost can also be reduced.

The invention discloses an SIW-based dual-frequency slot array antenna. The SIW-based dual-frequency slot array antenna comprises a dual-layer dielectric substrate, wherein a printed metal feeder is arranged on an upper surface of an upper-layer dielectric plate, a feeding slot, a low-frequency radiation slot and a high-frequency radiation slot are etched on an upper surface of a lower-layer dielectric substrate after copper coating, a lower surface is coated with copper, metal via holes are processed in four edges of the lower-layer dielectric plate, the two layers of dielectric plates are assembled and overlapped, the lower-layer dielectric substrate and metal on the upper surface and the lower surface thereof can form an SIW cavity, energy enters the SIW cavity at a lower layer from theprinted metal feeder at an upper layer via the feeding slot, a TE20 mode is formed, radiation of different frequency bands is achieved, low-frequency radiation arrays are arranged at two sides of a central axis of the antenna, a high-frequency radiation array is arranged on the central axis, and the design of the dual-frequency antenna and a relatively good directional diagram radiation effect are achieved. The SIW-based dual-frequency slot array antenna can be simultaneously applied to a microwave band and a millimeter wave band, is high in gain, wide in bandwidth, small in loss and low in profile and is easy to process.

The invention discloses a planar double-helix array of a double-frequency dual-polarization base-station antenna, which relates to double-frequency dual-polarization base-station antennas for mobile communication. The planar double-helix array is structurally characterized in that high-frequency fundamental oscillators (10) and low-frequency fundamental oscillators (20) are arranged on the front side of a reflector (30), a feed network (40) is arranged on the back side of the reflector (30), the high-frequency fundamental oscillators (10) alternately and bilaterally move pairwise to form a high-frequency radiation array, and the low-frequency fundamental oscillators (20) alternately, bilaterally and correspondingly move in the direction opposite to the moving direction of the high-frequency fundamental oscillators (10) to form a low-frequency radiation array. The horizontal beam width can be adjusted by adjusting laterally moving quantity of the fundamental oscillators in the horizontal direction, cross polarization discrimination ratio can be adjusted by adjusting the width of the reflector and the height of a side arm, wind resistance can be reduced by decreasing the width of the reflector, and space utilization rate of the antenna is increased. The planar double-helix array is applicable to the field of arrangement of high-frequency and low-frequency oscillators of the double-frequency dual-polarization base-station antenna.

The invention discloses a small size planar antenna with five frequency ranges being covered. The small size planar antenna with the five frequency ranges being covered structurally comprises a dielectric plate and a main metal earth plate, wherein the dielectric plate is provided with an antenna element in a positioning mode, and the main metal earth plate is arranged on the lower surface of the dielectric plate. The antenna element is of a planar composite structure, and comprises an L-shaped high frequency radiation unit and a bent rotary type low frequency radiation unit, wherein the L-shaped high frequency radiation unit is connected with a feed end, the bent rotary type low frequency radiation unit is coupled to the L-shaped high frequency radiation unit in a feeding mode and is provided with a lumped chip inductor, and the terminal of the bent rotary type low frequency radiation unit is connected with the main metal earth plate by the aid of a metallizing through hole. According to the small size planar antenna with the five frequency ranges being covered, a terminal antenna is small in occupied space and merely occupies one corner of a mobile phone mainboard, saved space can be reserved as a blank metal-free copper-coated substrate so that space is supplied for other antenna designs, and thus the small size planar antenna with the five frequency ranges being covered is applied to the existing multiple-input-multiple-output (MIMO) system. By the aid of the small size planar antenna with the five frequency ranges being covered, an expansion metal earth plate is increased, electromagnetic wave radiation to a human body is reduced, and moreover, the area can be provided with other connector elements in a matching mode, and thereby the size of the antenna is effectively decreased.

This invention relates to technology used for creating an enhanced artificial magnetosphere or electromagnetic shield for use in both manned and unmanned spacecraft. The invention includes an Interference Generating Pattern (IGP) which is tuned to the high-frequency radiation of X-rays and gamma rays and a conformal magnetic field. This technology will reduce the exposure of astronauts or other space travelers, as well as radiation-sensitive equipment, to the environmental hazards present therein. The net result will be reduced radiation intensity in order to create a space radiation-free environment as to render space travel safe.

The invention discloses a radiation unit, comprising two groups of orthorhombic half-wave vibrators and a feed supporting device. The radiation unit is characterized in that each half-wave vibrator comprises a vibrator arm connected with the feed supporting device; the free end of the vibration arm is bent downwards to form a space loading section; and a downward bending angle range of the space loading section is from 30 degrees to 90 degrees. Meanwhile, the invention further provides an antenna array formed by the radiation unit. The antenna array comprises a reflection board and a plurality of radiation units, and is characterized in that the radiation unit comprises a high-frequency radiation unit and a low-frequency radiation unit; each radiation unit is arranged along the symmetrical central line of the reflection board; and the two high-frequency radiation units are arranged between the two adjacent two low-frequency radiation units. With the adoption of the radiation unit and the antenna array provided by the invention, not only can the aperture size of the radiation unit be effectively reduced, but also the electric properties of pilot frequency isolation degree, directional diagram radiation properties and the like of the antenna in the array can be realized.