CST – Computer Simulation Technology

A Hemi-directional Antenna Array Concept for Automotive Radar

A Hemi-directional Antenna Array Concept for Automotive Radar
S. A. Askeland, T. Cella, J. Hjelmstad
Volume: 7, Issue: 2, 2011
New advances in mm-wave technologies are making phased array antenna systems feasible for automotive radar systems. In this paper, we introduce a new automotive radar system capable of wide angle tra±c monitoring. A narrow radar beam that is scanned over a wide ¯eld of view makes it possible to detect imminent collisions from vehicles approaching our vehicle head on or slantingly, and to monitor tra±c from the sides when our vehicle has stopped at a crossing road. The system will ultimately use a multidomain approach (angular, frequency, temporal) to achieve target detection and classi¯cation. In order to obtain both wide angle coverage and narrow beamwidth we employ a phased array antenna consisting of three 15 elements planar arrays mounted in three sectors. Each sector has 15 patch antenna elements. The sectors are placed at a 120± angle with each other. When scanning out to angles larger than §60± from broadside only the elements in the respective side sectors are used. When the scan angle is < §60± the elements in the front sector are used together with the elements in either the left or right sector (depending on which side the array is scanned to). For broadside direction, all elements are used. This means that the elements on the side sectors are scanned §60± relative to their broadside directions. By using all elements the array looks electronically larger, and hence a narrower beamwidth can be achived. To evaluate the performance of the array antenna radiation pattern simulations were run for 0±, 45± and 90± scan angle. The single element pattern and the pattern for the linear arrays in each sector were simulated in CST Microwave studio using a transient time domain solver, while the simulations for angles including elements from multiple sectors were simulated in Matlab Phased Array Design Toolbox by importing the single element pattern from CST and using conformal array theory. The simulation results show that the 3 dB- beamwidths and the side lobe levels for the individual beams are su±cient to obtain good target detection and classi¯cation over a more than 180± coverage when used with the multidomain approach. Hence, imminent collisions from head-on, front-side or straight from the sides at intersections can be detected and avoided.

Back to References

contact support

Your session has expired. Redirecting you to the login page...