Design of on 24GHz Bulter Matrix for Vehicle Radar

In this paper, a type of 24GHz Bulter matrix for vehicle radar is introduced. The Butler matrix network is formed with single-layered microstrip line structure. A 4x4 Butler matrix model with 24GHz central working frequency point is designed on the basis of design of 3dB directional coupler, 0dB crossover and phase shifter, as well as the Butler matrix principle. Meanwhile, 1x12 series feedback array antenna is designed as the output port of the feed network to form 4x12 multi-beam antenna arrays which is verified for its multi-beam properties through simulation.