A Low-sidelobe 24G-automotive radar antenna array with multi-mode excitation

A low profile 24 G-automotive radar antenna with dual - mode excitation is proposed. By adding ground metal discs which interacts with the main antenna to excite the dual - modes, it can introduce additional resonant points, thus enable the antenna to operate over a wider frequency range. When the antenna element operates at 24.35 GHz, the radiation patch excites the x-mode. Areas with large electric field amplitude show an +-shape. When the antenna element operates at a frequency of 26.15 GHz, the radiation patch excites the x- mode. Areas with large electric field amplitude show a x-shape. The antenna element is fed by a microstrip line and is easy to form an array. A 1 x 4 linear array and a 4 x 4 planar array are designed to reduce the antenna area by the combination of series and parallel feeders. Using the Taylor power distribution, the power ratio of the two antenna elements on both sides of the linear array is 1:2, and the low sidelobe characteristics are obtained. The simulation results of antenna element -10dB impedance bandwidth range are 22.65 - 27.00 GHz, antenna linear array -10 dB impedance bandwidth range is 20.52 - 25.96 GHz, antenna planar array -10 dB impedance bandwidth range is 23.10 - 25.17 GHz. The simulated results of main and sidelobe gain ratio of antenna linear array and antenna planar array reach 18.5 dB and 11.41 dB respectively at 24 GHz, 12.7 dB and 10.3 dB respectively at 25 GHz.