Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, Iran
In this research work, a multibeam antenna which is a combination of a beamformer network (BFN) and a linear array antenna, has been designed. A Rotman lens has been chosen as beamformer network and Vivaldi antennas have been selected for constructing array antenna. The Substrate Integrated Waveguide (SIW) was used for implementing Rotman lens. After explanation the structure of Substrate integrated waveguide, a prototype SIW Rotman lens was designed to create 7 beams at angles of 0°, ±10°, ±20° and ±30°. Each beam is corresponding to one of the input port of Rotman lens. This Rotman lens was designed for aeronautical applications and operates at center frequency of 16 GHz and frequency bandwidth of 1 GHz. It was found that the amplitude and phase distributions at output ports of Rotman lens are appropriate. Then a linear array of 7 Vivaldi antennas was connected to the Rotman lens to realize the multibeam Rotman lens antenna.