Multi-beam antenna device

Abstract

Provided is a multi-beam antenna device capable of achieving two independent multi-beam characteristics using a single antenna unit, and enhanced gain. The multi-beam antenna device comprises a first antenna section, a second antenna section, a first Rotman lens section and a second Rotman lens section, which are laminated together in this order to form a planar antenna module. A first multi-beam characteristic is achieved by the first antenna section and the first Rotman lens section, and a second multi-beam characteristic is achieved by the second antenna section and the second Rotman lens section, independently. A Rotman lens in each of the Rotman lens sections is designed such that: β with respect to α is set to satisfy the following relation: β<α, where β is a spatial beam-forming angle of an array antenna, and α is an elevation angle between a center line (), and a line segment which connects one of an input port and an intersecting point S; and a shape of a Rotman lens is set to satisfy the following relation: η=(β/α)·(Ln/F)<1, and reduce G to less than a basic value of G when designed under a defined condition of β=α, where: F is a distance between the input port and S; G is a size of the Rotman lens; and 2 Ln is the aperture length of an array antenna.