Abstract:
An unmanned high altitude aircraft operating above 15 km with transmitting and/or receiving antennas, enclosed or more than half enclosed on a projected area basis normal to the plane of the antenna (s), in a wing structure where the chord length of the wing section enclosing the phased arrays or horn antennas is at least 30 percent greater than the mean wing chord length, and the wing surface adjacent to the antenna(s) in the path of the electromagnetic radiation being received or transmitted by the antenna (s) is substantially composed of material relatively transparent to this radiation.
Abstract:
Winkelauflösender FMCW-Radarsensor mit mehreren Antennenelementen, die in einer Richtung, in welcher der Radarsensor winkelauflösend ist, in verschiedenen Positionen angeordnet sind und mindestens drei Sendearrays sowie mindestens ein Empfangsarray bilden, und mit einer Steuer- und Auswerteeinrichtung, die für eine Betriebsweise ausgelegt ist, bei der die mindestens drei Sendearrays periodisch Signale senden, deren Frequenz gemäß einer Folge von Modulationsrampen moduliert ist und bei der Radarechos der gesendeten Signale jeweils von mehreren Antennenelementen des mindestens einen Empfangsarrays empfangen werden und der Winkel eines georteten Objekts anhand von Amplituden- und/oder Phasenbeziehungen zwischen Radarechos bestimmt wird, die unterschiedlichen Kombinationen von Sende- und Empfangsarrays entsprechen, wobei ein Messzyklus des Radarsensors mindestens zwei Perioden umfasst, in denen jeweils zwischen mindestens zwei Kombinationen von Sende- und Empfangsarrays gewechselt wird, und dass die beteiligten Kombinationen von Sende- und Empfangsarrays für die mindestens zwei Perioden voneinander verschieden sind.
Abstract:
A broad-band circularly- polarised antenna is presented. The circularly-polarised antenna includes at least four monopole antenna elements having respective at least four radiating surfaces with respective at least four normals. The monopole antenna elements are arranged around a vertical axis. The normals of the respective radiating surfaces are perpendicular to and point away from the vertical axis. The broad-band circularly-polarized antenna include s at least one feed network communicatively coupled to edge portions of the at least four mono pole antenna elements. A first antenna element is driven with a first driving phase offset by 90 degrees from a second driving phase used to drive a second antenna element. Tie second driving phase is offset by 90 degrees from a third driving phase used to drive a third monopole antenna element. The third driving phase is offset by 90 degrees from a fourth driving phase used to drive a fourth antenna element.
Abstract:
A superluminal antenna element integrates a balun element to better impedance match an input cable or waveguide to a dielectric radiator element, thus preventing stray reflections and consequent undesirable radiation. For example, a dielectric housing material can be used that has a cutout area. A cable can extend into the cutout area. A triangular conductor can function as an impednace transition. An additional cylindrical element functions as a sleeve balun to better impedance match the radiator element to the cable.
Abstract:
A radar system for forming a scanning receive beam from signals received by a phased array (4) having a plurality of sub arrays (6), comprises a plurality of phase units (8) each configured to receive a said signal from one or more sub arrays. Each phase unit (8) comprises a waveform generator (18) configured to generate an analogue waveform having a frequency corresponding to a time-varying phase shift. Each waveform generator (18) is arranged to digitally generate the analogue waveform, and output a comparison of the received signal with the waveform, incorporating the time-varying phase shift. The system further comprises a combining unit (10) configured to combine the outputs from the plurality of phase units (8) to form a scanning receive beam.
Abstract:
A spacecraft (100) includes a spacecraft body or bus (102) with support members (104A, 104B) to fasten solar panels (106A, 106B) to the spacecraft (100). Mounted on the spacecraft bus (102) are antennae (116, 118), which are concentric with each other and are centered symmetrically about a yaw axis of rotation (120) of the spacecraft (100). The solar panels (106A, 106B) produce electrical energy for use hi the spacecraft (100).
Abstract:
A method for synthesizing an array factor for an array antenna based on a target shape of an array factor amplitude, comprising: calculating an array factor phase based on the target shape of the array factor amplitude, and calculating array antenna weight coefficients using the Least Mean Square method, where a target function used in the LMS method is a complex function composed by said target shape of the array factor amplitude and the calculated array factor phase, wherein the calculated weight coefficients determine the array factor.
Abstract:
The spacing between adjacent receiving antennas of an ULA located in a base station of a cellular communication system is optimized to both the channel and the interference space-time multipath. The spacing is lager than the canonical λ/2 for introducing a certain degree of angular equivocation aimed to see the interferers (all or a certain number depending on the degree of freedom of the directivity function) as they were grouped together along an unique direction. In an ideal case of fixed interferers with null angular power spread, a given cellular planning and known aperture of the array, the optimal spacing Δ opt between adjacent antennas is directly calculable in closed mathematical form in function of the equal angular separation Δ θ between the DOAs of the interferers. When the restrictive hypotheses are neglected, the optimal spacing Δ opt is calculable as the spacing that minimizes the spread between the N I wave numbers associated to the barycentric DOAs of the N I interfering cells. Moreover closed form solution can be dealt with on condition that N I interfering cells (with one broadside interfering cell) are considered; said angular separation between the interferers is assumed as being the average Δ θ B among adjacent angular separations between barycentric DOAs weighted by the respective barycentric received power. Assuming a multipath channel with an arbitrary number of paths N p , the i th barycentric DOA is calculated by executing a weighted average extended to the N p x S directions of arrival of the N p paths by the S points of a grid indicative of the positions spanned by the i th interfering station inside its cell, weighting each DOA by the power received on that path. In a SIMO scenario with square cell planning according to the fixed or mobile WiMAX IEEE 802.16d802.16-2004/e, the value A opt = 1.8λ is found as an optimum trade-off between beamforming and diversity (fig.5).
Abstract:
The invention concerns an array plane antenna (1, 1’), comprising a set of at least two reception and/or5 transmission radiating elements fed by means of at least one beam forming network or BFN of the parallel type, characterised in that each one of said radiating elements comprises a shaped aperture (2), and in that at least one BFN network is made through wave guides (3) directly obtained from the bulk of the antenna (1, 1’), so that each one of the shaped apertures (2) is an input and/or output horn (4) of a wave guide (3) of the BFN network. The invention further concerns the process of manufacturing such plane antenna.