摘要:
A reflector assembly (100) implementable in a scanning antenna assembly (520) having a stationary surface (120) includes a support assembly (110) coupled to the stationary surface (120), a substantially planar first reflector panel (130) coupled to the support assembly (110) so as to enable rotation of the first reflector panel (130) about a central axis of the first reflector panel (130), and an actuator assembly (140) comprising a translating arm (160) coupled to the first reflector panel (130), wherein translational motion of the arm (160) is operable to rotate the first reflector panel (130) about the central axis back and forth through a predetermined angular range at a predetermined frequency.
摘要:
Array fed multiple beam antenna systems and methods for use on an orbiting spacecraft carrying a communication system. The antenna systems include a reflector and a relatively small array feed compared to the reflector. The array feed has feeds (radiators) that illuminate the reflector and that are disposed in a focal plane of the reflector. A power division network excites the radiators of the feeds. The antenna system is capable of very wide scan angle operation and may be used to provide multiple spot beam coverage over the surface of the Earth viewed from a synchronous orbit spacecraft.
摘要:
An antenna system comprising a first reflector (202) and a second reflector (204) is disclosed. The first reflector (202) reflects an incident signal from a signal source (208). The incident signal comprises a first signal having a first polarization and a second signal having a second polarization. The first reflector (202) has a surface that reflects the first signal and the second signal. The second reflector (204) receives the reflected incident signal from the first reflector (202) and comprises a first reflective surface (206) for reflecting the first signal and a second reflective surface (210) for reflecting the second signal.
摘要:
Antenne à double réflecteur de type Cassegrain, permettant d'utiliser, d'une part les qualités d'un faisceau fin conventionnel pour les fonctions de poursuite et permettant, d'autre part, de pouvoir disposer d'un faisceau élargi pour l'acquisition d'objectif, l'antenne comportant pour cela outre le réflecteur principal (2) et un réflecteur auxiliaire semi-transparent (3), une source (1) émettant des ondes à polarisations croisées, une lentille (5) placée derrière le réflecteur auxiliaire (3) qui permet d'obtenir un plan équiphase par focalisation des ondes traversant le réflecteur auxiliaire (3), provoquant ainsi un élargissement du faisceau. Application aux radars de poursuite.
摘要:
There are a number of occasions when it is desirable for a radar system to be capable of transceiving two distinct signals from a single location. Indeed, it may be the case that it is required to be able to use a «single» antenna simultaneously to transceive the two signals in such a way that the sections of the system dealing with one signal are in no way influenced by the other signal. Various ways of attaining the desired end have been suggested in the past, but none have proved entirely satisfactory. The present invention seeks to deal with the requirement for the simultaneous transception of two high power signals by the simple, but apparently previously unconsidered, expedient of employing a radar antenna assembly comprising two separate antennae (11/12, 14) arranged closely together in tandem, the fore antenna (14) being a direct antenna and the rear antenna (11/12) being a Cassegrain antenna, the reflector of the former being transparent to the radiation transceived by the latter.
摘要:
Dispositif réducteur de brouillage en polarisation rectiligne tournante comportant une antenne du type Cassegrain à rotation de polarisation, le réseau (5) de fils réflecteurs, qui constitue avec le miroir (4) le réflecteur principal (2), étant placé par rapport au miroir à une distance déterminée, inférieure au quart de la longueur d'onde à la fréquence centrale de la bande de fonctionnement, de sorte qu'il conserve le même zéro d'écartométrie quelle que soit la direction de la polarisation rectiligne tournante du brouilleur. Application à un radar de poursuite et d'écartométrie.