Patent ID: 8698689
Filing Date: 2014-04-15
Classification: H01Q

Abstract:
1. A multi-beam antenna device comprising: a Rotman lens having a plurality of input ports for feeding electric power, and a plurality of output ports for extracting the electric power from the input ports; an array antenna comprised of a plurality of antenna elements and adapted to radiate electromagnetic waves to space; and a plurality of transmission lines connecting respective ones of the output ports to respective ones of the antenna elements, wherein a curve for arranging the output ports thereon and a length of each of the transmission lines are set such that, when a given one of the input ports is excited, a beam is formed in a direction at an angle corresponding to that of the given input port, characterized in that: β with respect to α is set to satisfy the following relation: β<α, where: β is a spatial beam-forming angle of the array antenna when viewed from a direction facing a front of the array antenna; and α is an angle between a center line of the Rotman lens, and a line segment which connects one of the input ports and an intersecting point S a shape of the Rotman lens is set to satisfy the following relation: η=(β/α)(Ln/F)<1, and reduce G to less than a value of G when designed under a condition of β=α, where: F is a distance between the one input port and S