Phase management for extended scan range antenna arrays based on Rotman lens

This paper presents an implementation of a technique aimed to double the scanning range of a 24 GHz array antenna system based on Rotman lens beamforming. The new concept of the enhanced beam forming network consists of a combination of Rotman lens and 1-bit phase shifters, positioned in a peculiar way on the array side of the lens, and together with a particular beam arrangement allows to overcome the scan limitations which is typical of the standalone Rotman lens solution. Simulations will demonstrate that a Rotman lens, designed to steer the beam up to ±30°, when arranged in combination with properly designed Ratrace based phase shifters, allows to increase the scan range up to ±60°.