Multiple arm spiral antenna system with multiple beamforming capability

摘要

A multifunction antenna system is provided which has adaptive beam forming capabilities for transmitting and receiving signals having various beam patterns over a hemispherical field of view. The antenna system includes a beamformer having an array of N spiral arm elements for transmitting and receiving a radiating beam. N analytic voltage signals are produced by the N cylindrically symmetric spiral arm elements in relation to the radiating beam. A beam processor is further provided for selecting the appropriate combination of vector weight coefficients in response to input data. The beam processor loads the selected N vector weights into a vector weighter. In the transmit mode, the vector weighter multiplies the selected vector weights by an input signal to produce the N analytic signals which are then applied to the multiple arm spiral antenna and transmitted therefrom. In the receive mode, the vector weighter multiplies the N analytic signals received by the selected N vector weights to obtain information from the desired direction. The antenna system is further capable of processing the signals received and providing adaptive beam patterns in response thereto.