77GHz High Gain Antenna Based on Microstrip Coupling Excitation

In this paper, a 77GHz high-gain antenna that can be applied to automotive angle radar is proposed. The antenna is composed of two layers of dielectric substrates with the same thickness and the same dielectric constant. The lower layer forms a spatial electromagnetic field by feeding the microstrip line, then, the electromagnetic coupling between the microstrip line and the upper metal patch is used to form an H-plane wide beam. In order to increase the surface current on the metal patch, the gain is improved by connecting the patch and the microstrip line by metallized vias in the upper medium. Finally, the antenna achieves |S11|<-10dB within 77~78.43GHz. The 3dB beam width of the H-plane is greater than 81.5°, and the gain is greater than 16.1dBi in the bandwidth.