237 results about "Ku band" patented technology

The present invention relates to an electromagnetic wave transmission/reception source for a multireflector antenna of the Cassegrain type comprising longitudinal-radiation means operating in a first frequency band and an array of n radiating elements of the travelling-wave type operating in a second frequency band with the n radiating elements arranged symmetrically around the longitudinal-radiation means, the array and the longitudinal-radiation means having an approximately common phase centre, the array of n radiating elements being excited by a waveguide of polygonal cross section. The invention applies especially in satellite communication systems operating in the C-, Ku- or Ka-bands.

A method and system for a plurality of airplanes in flight to receive from and send to a plurality of ground stations broadcast and communication signals through a single or a plurality of geostationary satellites, wherein at least the mobile link between said airplanes and said satellite, uplink or downlink, uses the high frequency radio waves at 17 GHz or higher, such as Ka-band. The fixed link between said satellite and said ground stations may use any radio frequencies below the frequencies used to communicate between the satellite and the aircraft. The lower frequencies tend to be less susceptible to rain attenuation and hence suitable for closing the fixed broadcast and communication link. Frequencies such as C-band or Ku-band, or even Ka-band, are applied between satellite and ground such that the available link margin is sufficient to overcome rain attenuation at said ground stations. Said satellite carries a plurality of transponders that may include a plurality of frequency converters to enable the conversion between different frequencies. Said satellite generates a plurality of spot beams, shaped or unshaped, which collectively cover the flight routes of said airplanes, preferably the geodesic path between two highly populated regions.

The present invention provides an improved antenna system on moving platform that is in communication with multiple satellites for simultaneous reception and transmission of RF energy at multiple frequencies. The antenna is implemented as a multi-beam, multi-band antenna having a main reflector with multiple feed horns and a sub-reflector having a reflective surface defining an image focus for a Ka band frequency signal and a prime focus for a Ku band frequency signal.

Boeing achieves satellite diversity by having a large discrimination angle for a MEO constellation of communications satellites to limit interference in the Ku-band with GSO communications systems. Each satellite entering an exclusion zone over a GSO ground station terminates all transmissions to provide EPFD within acceptable limits. The Boeing MEO constellation preferably comprises 20 satellites, 5 in each orbit. The four orbits are inclined at about 57° with respect to the equator. Services include an Integrated Digital Service (IDS) and Backhaul Data Service (BDS) to accommodate the needs of different users.

The present invention is a wide band GaAs microwave monolithic integrated circuit (MMIC) transmit chip that is capable of transmitting linearly or circularly polarized signals when connected to a pair of orthogonal cross-polarized antennas. In an active phased-array antenna environment, this transmit chip is capable of transmitting signals with different scan angles. This invention also contains a digital serial to parallel converter that uses TTL signal to control the phase shifter and attenuator circuits that are required for controlling the polarization and scan angle of the transmitted signal.

A Ku-band low-profile dual-frequency dual-polarization array antenna in the field of satellite communication technology, a multi-layer sandwich structure composed of eight layers, followed by a parasitic unit layer, a first dielectric plate layer, an air layer, an excitation unit and a first The polarized feeding matching network layer, the second dielectric board layer, the grounding board layer, the third dielectric board layer and the second polarized feeding matching network layer. The invention can meet the impedance broadband requirement of the receiving and receiving frequency band of the current Ku-band satellite communication, and the isolation degree of the horizontal polarization and the vertical polarization port is better than 30dB.

The invention relates to a four-band multi-polarization co-aperture feed source. The four-band multi-polarization co-aperture feed source is formed by combining a double linear polarization antenna of a Ku band and a double circular polarization antenna of a Ka band and comprises a conical horn, a Ku circular waveguide, a tuning screw, a Ku flange, a horizontal polarization power divider, a first flange, a vertical polarization power divider, a medium rod, a circular waveguide feed window, a stop screw, a transition section and a double circular polarization antenna. The antenna of the Ku band uses four ports for symmetrical feeding to improve the symmetrical characteristic of a directional diagram, a transmission waveguide of an electromagnetic field of the Ku band is used as the transition section of the electromagnetic field of the Ka band, and the resonance medium rod is embedded into the waveguide of the Ku band for transmitting electromagnetic waves of the Ka band so that compactness of the antenna is greatly improved. By means of dielectric waveguides and conical horn nesting technologies, the purposes of achieving antenna beam conformity and sharing one phase center are achieved, uniformities of directional diagrams and uniformities of the phase centers in four working bands are guaranteed, isolation among bands is increased, and the compactness of the antenna is improved.

The present invention relates to a dumbbell-shaped slot coupling excitation-based wideband low-profile microstrip antenna. The dumbbell-shaped slot coupling excitation-based wideband low-profile microstrip antenna comprises a rectangular radiation patch, a metallized isolation via hole array, an inner-layer metal ground board, a dumbbell-shaped coupling slot, a strip line feeder, a quasi-coaxial vertical interconnection structure, a microstrip feeder, an annular opening pad and an SMP connector for feeding. The antenna is constructed by using a laminated PCB technology; a three-dimensional transmission structure is constructed through a microstrip-quasi-coaxial metallized via hole-strip line structure; and the rectangular radiation patch is excited based on the special dumbbell-shaped coupling slot. The antenna has the advantages of compact structure, small horizontal dimension, low profile, low cost, easiness in processing, easiness in integration and the like, and can meet the use requirements of 12 GHz-to-18 GHz Ku bands and is very suitable for being applied to a Ku- band wideband phased array system.

The invention relates to a broad-band high-gain scannable panel antenna of parabolic reflection surface feeding. A radiation unit is a step-type variable inclination continuous transverse stub groove (VICTS). A feeding network comprises a series connection feeding structure and a parabolic reflection surface feeding network. An electromagnetic wave is reflected into a plane wave through the parabolic reflection surface type feeding network, is coupled to an upper-layer series connection feeding network and finally is radiated to a free space through the VICTS. Through relative rotation between upper and lower layers of a parallel plate waveguide, wave beam scanning is realized. The antenna of the invention covers a satellite communication ku wave band, an antenna work frequency is 10.2GHz-14.8GHz and an impedance bandwidth reaches 36.8%. At a 13GHz frequency point, a 25.7dBi gain is possessed. A antenna scanning angle scope is from 0 DEG to 56 DEG. Compared to a traditional communication in moving system antenna, by using the antenna of the invention, the feeding is simple; wave beam scanning is easy to realize; a dynamic response is fast and is in a panel shape; and a large engineering application prospect is possessed.

A triple-band offset hybrid antenna having a shaped reflector is disclosed. The triple-band offset hybrid antenna includes: a shaped reflector reflecting a K/Ku bands RF signals received from a satellite to focus an energy of the K/Ku band RF signals on a focal line and reflecting a Ka band RF transmitting signal; and a triple-band active phased feed array receiving the reflected K/Ku bands RF signals from the shaped reflector and radiating the Ka band RF transmitting signal to the shaped reflector, wherein the triple-active feed array including Ka/K bands feed array for transceiving Ka/K bands RF signal and a Ku band feed array for receiving a Ku band RF signal.

Techniques for enabling broadband data rates at mobile terminals in a beyond-line-of-sight communication system are disclosed. Forward link time-diversity transmission methods and a time-diversity transmitter based upon blockage characteristics are provided. The transmitter optionally supports selective time-diversity and can operate at Ku-band or higher frequencies. A forward link time-diversity receiver and methods for receiving a forward link time-diversity signal are also disclosed. The forward link time-diversity receiver optionally provides low-jitter or low-delay characteristics. A return link transmitter and return link transmit methods which avoid blockages are also disclosed. The return link transmitter can include a signal presence detector and blockage prediction filter.

The present invention provides a feed network of wideband array antenna which is used for wireless communication field. The present invention comprises of microstrip antenna radiation cell, radiation antenna medium substrate, microstrip mirrored unit, coaxial line feed cell, grounding board, feed network medium substrate, microstrip feed network and feed port from top to down in turn. Feed port is connected with microstrip, grounding board and feed network are set on upper surface and lower surface of feed network medium substrate, microstrip feed network is separated with radiation antenna medium substrate by grounding board and air microstrip, microstrip antenna radiation cell, microstrip mirrored unit and microstrip feed network are connected by coaxial line feed cell. The present invention can work efficiently on ku wave band (11.75-12.75GHz), and the array antenna has merits of high plus, low sidelobe and steady structure.

The invention relates to a high-temperature wave-absorbing composite material and a preparation method thereof and provides a SiC@SiO2@ferrite high-temperature wave-absorbing composite material and apreparation method thereof. The objective of the invention is to overcome the technical problems of complex preparation technologies, narrow wave-absorbing ranges and no shielding effect of conventional wave-absorbing material preparation methods. The wave-absorbing composite material uses SiC as a core; a SiO2 layer coats the core; and ferrite particles are adhered onto the SiO2 layer. The preparation method comprises the following steps: 1, pretreating the surface of silicon carbide; 2, synthesizing silica-coated silicon carbide SiC@SiO2; 3, after sensitization and activation of SiC@SiO2, reacting the SiC@SiO2 with a salt for preparing ferrite and a strong reducing agent in alkaline liquor, then carrying out calcination so as to obtain the SiC@SiO2@ferrite high-temperature wave-absorbingcomposite material. The material of the invention has a reflection loss of less than -5dB in a 8-to-12-GHz band and a Ku band and a maximum reflection loss of -14 dB, and can be used in the field ofwave-absorbing materials.

The invention discloses a high-power low-PIM (passive intermodulation) broadband polarized frequency duplexing feed assembly in a Ku frequency band, comprising a symmetrical two-arm orthogonal modal coupler and two frequency duplexers, wherein the symmetrical two-arm orthogonal modal coupler comprises an inner structure and a shell; the inner structure comprises a public square waveguide, a symmetrical two-arm coupling access and a longitudinal straight access, thus forming a public port, a symmetrical two-arm synthetic port and a longitudinal straight port; two side faces of the public square waveguide are provided with two rectangle coupling windows with the same size symmetrically; an inductive column which is parallel to and has the same length with a long edge of the rectangle coupling window is inserted into the middle point of a short edge of each rectangle coupling window; and a shaping diaphragm which is vertically connected with the rectangle coupling windows at two sides is inserted into the center in the public square waveguide. According to the assembly, the symmetrical two-arm orthogonal modal coupler is connected to the two frequency duplexers to finish the polar duplex and the frequency duplex of signals, thus solving the two traditional technical problems of the polar duplex and the frequency duplex of an antenna system at the Ku frequency band. The special shaping curve diaphragms and the inductive columns are utilized in the symmetrical two-arm orthogonal modal coupler, thus realizing the broadband matching and avoiding the asymmetrical higher order modes. The assembly has the advantage of compact structure.

The invention discloses a satellite communication frequency conversion terminal equipment of a Ku band. The satellite communication frequency conversion terminal equipment of the Ku band comprises a frequency conversion processing module used for converting a received intermediate frequency signal of an L band into a radio-frequency signal of a Ku band; a power amplification module, which comprises a preceding stage drive unit, a secondary driving unit and a last stage synthesis unit that are orderly connected, wherein the power amplification module is used for performing power amplification on the radio-frequency signal of the Ku band outputted by the frequency conversion processing module, and realizing the high power output of the radio-frequency signal of the Ku band; and a monitoring and control module used for detecting the output power of the power amplification module, and controlling a variable attenuator in the preceding stage drive unit of the power amplification module according to a comparison result with the scheduled output power, so that the output power of the power amplification module can be locked. According to the satellite communication frequency conversion terminal equipment of the Ku band provided by the invention, by setting the multistage cascaded power amplification unit, the technical problems of high-power synthesis and efficient heat dissipation can be solved, and the design of consistent and balanced amplitude and phase can be realized.

A phased-array antenna that includes a photonic beamformer is disclosed. In some embodiments, a front stage of electrical-domain processing applies a 16-to-1 signal-combination ratio, a single stage of photonic beamforming applies a 4-to-1 signal-combination ratio, and a passive, electrical-domain, signal combiner applies a 32-to-1 signal-combination ratio.

A feed assembly (26) for an antenna system (38) includes a first feed element (30) that propagates a first beam (32) and a second feed element (34) that propagates a second beam (36). The second feed element (34) is collocated with, but displaced vertically from, the first feed element (30) to achieve angular diversity in elevation. Each of the feed elements (30, 34) has an elongated conical shape and is formed from a dielectric material. The feed assembly (26) operates within the Ku-band frequency range to yield high gain, collimated, independent first and second beams (32, 34). The feed assembly (26) can be implemented in a tropospheric scatter communication system (38) in conjunction with a reflector (22) to provide concurrent transmit and receive capability via the two independent, angularly separated first and second beams (32, 36).

The invention provides an X-and-Ku-waveband power-adjustable microwave source. The device work mode can be changed through regulating the length of an inner conductor, and the X-and-Ku-waveband crossing conversion of the work frequency can be realized.

A low-differential-loss low-phase-shift high-integration-level five-level marching type ultra-wide-band numerical control attenuator is formed by a single signal channel which comprises a transmission line TL0, an 8dB attenuation module of a pai-type structure, an inductor L1, a 0-7dB combined attenuation module of a T type-bridge T type combined structure, an inductor L2, a 16dB attenuation module of a pai-type structure and a transmission TL1 in a cascaded mode in sequence based on the RF CMOS technology. An MOS tube is used as a control switch, five independent control ends controls three attenuation modules to work, an inducting network is used for phase compensation, working frequency range is Ku wave band within the attenuation range of 0-31 dB with marching length of 1dB, and 32-state low-differential-loss low-phase-shift signal amplitude attenuation can be achieved. The attenuator has the advantages of being low in differential loss, low in additional phase shift, low in production cost, small in chip area and compatible with a digital processing module, and the attenuator can be used for single-chip ultra-wide-band communication system integration.

The invention relates to a light and small type permanent magnetic packaging Ku waveband coaxial transition device. The cathode A of a focusing cathode E is loaded; explosion electronic emission occurs under the condition of externally added high voltage; after electronic beams pass cascading double resonance reflection cavities, initial speed pre-modulation is acquired; speed modulation is completely converted into density modulation; high-frequency electric fields in the cavities are extracted and sufficient interactions occur between the high-frequency electric fields and clustering electronics transmitted therein; generated Ku waveband HPM is externally coupled and output through coaxial output waves; and finally, coaxial grooves in an inner conductor B absorb electronic beams of restenergy. The intensity of the generated electric fields is 0.3T, the weight of the permanent magnet is 63.5kg; and under the guidance magnetic field, effective emission and transmission of the electronic beams are achieved. By introducing the cascading double resonance reflection cavities, coupling of the electromagnetic fields in the modulation cavities to diode regions is reduced, radial fluctuation of the electronic beams is reduced and the required guidance magnetic field is reduced. The working mode of the device is TM02, so the novel device is allowed to have quite high power cavity in the Ku waveband.