Codesign of 77GHz automotive radar double-resonance millimeter wave slot taper-patch antenna and compact waveguide-microstrip transition

A 77GHz series fed three element taper-patch antenna with compact waveguide to microstrip transistion is presented for automotive radar application. In order to resolve the narrow band issue of conventional taper-patch antenna, slots were cutted at the input of each element, to provide a second resonance frequency to achieve wider bandwidth. Together with microstrip transition, the proposed antenna has a -10dB return loss bandwidth(75.75-79.9GHz) of 4.1GHz, and a maximum gain of 9.7dBi.