摘要:
The device has a primary radiator (3) e.g. multi frequency feed horn radiator, and a rotation symmetric main reflector (1). Focusing parameters and moving speeds of drive units e.g. small motor (8) and eccentric disk (18), are adjusted, so that complete continuous microwave scanning of a scene is done by a focusing mark. A receiver-sided evaluation device is formed such that image data, which are synchronous in a position, are received and stored, combined to an image and represented or reprocessed on-line or off-line, based on determination of trajectory of the mark.
摘要:
A small and compact lens antenna system in which a radio wave having a large incident angle from a circulating satellite as well as a geostationary satellite can be received without reducing the gain by combining a hemispherical lens and a reflector as one kind of Luneberg type antenna so that a radiator receives radio wave while converging. The lens antenna system comprises a lens antenna body (10) including a reflector (13) and a hemispherical lens (14) composed of a laminate of dielectric material mounted rotatably on a base plate (11) while being protected entirely with a radome (17) and radiators (16a, 16b) movable to an arbitrary position along a guide rail (15), and a reflector supporting means (20) capable of inclining the reflector (13) in an arbitrary direction on a base (21), wherein the incident angle of radio wave from a satellite can be adjusted to a desired range by inclining the reflector (13).
摘要:
An antenna comprising a feed (42) for delivering electromagnetic energy to a rotatable combination of a dielectric lens (44) and a reflective surface (46). The combination of the dielectric lens and the reflective surface is placed proximate to and in front of an energy feed, such as a horn (42), to support the scanning of an antenna beam in response to rotation of the lens/reflective surface assembly. The lens typically comprises a dielectric material and the reflective surface can comprise a thin layer of material operable to reflect electromagnetic energy. For example, the lens can comprise a half-cylinder shape of dielectric material and the reflective surface can be applied to the flat portion of the half-cylindrical lens. Alternatively, the antenna can comprise two or more electromagnetic feeds (72a, 72b, 72c, 72d) and a cylindrical lens of dielectric material including a centrally embedded, two-sided reflective surface. A positioning system can be used to rotate the combination of the lens and the reflective material proximate to and in front of the electromagnetic feed(s).
摘要:
The invention relates to a radio device (1) which allows for a more flexible antenna. The inventive radio device (1) comprises a housing (5) with a listening device (15) on a first side (10) and an antenna element (25) on a second side (20), said second side being opposite said first side (10). The antenna element (25) is positioned on the second side (20) of the housing (5) in such a way that it can move. Said antenna element (25) has a directional radiation characteristic in at least one first position (31, 32, 35, 36) and an omnidirectional radiation characteristic in at least one second position (33, 34, 37, 38).
摘要:
The antenna has an inflatable support structure (80) to which a reflective material surface (60) is attached by a tensionable attachment arrangement allowing deployment of the reflector from, for example, a space vehicle (90). The reflective surface (60) is for energy incident from an antenna feed horn (65). Upon being inflated, the support structure places the attachment arrangement (70) in tension and causes the reflective surface (60) to acquire an intended reflective surface geometry, e.g. a parabolic mesh surface. The inflatable support structure (80) is transparant to energy and is formed either as a toroid (80) surrounding the reflective surface (60) or as an elliptical or spherical balloon (30) enveloping the reflective surface (10 in Fig.1). The antenna is used in airborne and spaceborne applications and has the advantage that the antenna reflector is insensitive to variations in pressure, the intended antenna profile does not change and the energy gathering and focussing properties are not impaired.
摘要:
A phased array antenna system has at least one trough reflector, each trough reflector having at least one phased array located at a feed point of the reflector, and an array of elements located near to a point equal to one half of a center transmission wavelength. A method of decoding a receive signal includes propagating a transmit signal through a transmit and a receive path of a phased array to generate a coupled signal, digitizing the coupled signal, storing the digitized coupled signal, receiving a signal from a target, and using the digitized coupled signal to decode the signal from the target. A method of modeling the ionosphere includes transmitting measuring pulses from an incoherent scattering radar transmitter, receiving incoherent scatter from the transmitting, and analyzing the incoherent scatter to determine pulse and amplitude of the incoherent scatter to profile electron number density of the ionosphere.