Vehicular Bidirectional Internal Antenna with Asymmetric Gain Characteristics to Compensate for Backward Link Path Loss due to Interior Obstacles

Abstract

Wireless communication technologies are expected to become essential in future self-driving vehicles. This study presents an antenna for vehicle wireless communication with a bandwidth of 75 MHz at a Wireless Access in Vehicular Environment frequency of 5.885 GHz. To compensate for the backward link path loss from the vehicle interior and passengers, the antenna is designed to have asymmetric gains of 0 and 6 dBi at 0° and 180°, respectively. The antenna is validated through an outdoor road test. We measured the received continuous-wave (CW) power, received signal strength indicator, and packet-delivered ratio (PDR) of the digital signal under vehicle-to-vehicle communication mode. Similar power is received in both the backward and forward scenarios. The forward and backward PDR are also similar.