Planar series-fed antenna array for 77 GHz automotive radar

An antenna array with 3 transmit antennas and 4 receive antennas for the 77 GHz automotive radar is presented. Each antenna is a planar series-fed linear array. The Dolph-Chebyshev distribution is used to taper patch width for radiation pattern synthesis. The planar array is designed, fabricated, and its performance evaluated. Simulation results show that a 16-element series-fed microstrip linear array can achieve the sidelobe level (SLL) of -16.8 dB with half power beamwidth (HPBW) of 5.8°. The simulated and measured results show that a linear array in the planar array can realize the SLL of -15.5 dB with HPBW of 6.0° in simulation and the SLL of -10.5 dB with HPBW of 6.5° in measurement, respectively. And measured antenna gain is not less than 15.0 dBi.