Design and simulation of a high efficiency Rotman lens for mm-wave collision avoidance sensor

Abstract

Multi-beam approaches using beamforming antenna array architectures have been identified as one solution for overcoming the limited fields-of-view provided by highly directional mm-wave sensors. They are also ideal front end systems for collision avoidance devices. Rotman lenses offer a compact, rugged and reliable alternative to electronically scanned antenna technologies but architectures that operate at frequencies <20 GHz perform poorly at higher frequencies on account of greater losses and dispersion. This paper outlines the design process for providing Rotman-based lenses, examining various levels of simulation that are needed for designs that function at K and W-band frequencies. The impact of using microstrip structures is demonstrated. A key advantage of our approach is that it is compatible with monolithic fabrication, leading the way towards smart collision avoidance sensors.