Design of multi-frequency compact antennas for automotive communications

Two designs of multi-band antennas for automotive communications are presented. Both antennas are designed to operate in four frequency bands (GSM, E-GSM, DCS, PCS) and are intended to be integrated in a PCB, placed inside a plastic box and mounted under the dashboard of the vehicle. The first design is a planar printed antenna fully integrated into the printed circuit board (PCB), thus reducing the cost virtually to zero; the second design is a three dimensional antenna, which does not require any dedicated space on the PCB. Both antennas have been designed taking into account the presence of the other electronic components on the PCB. The simulated reflection coefficients and radiation patterns of both antennas are in good agreement with prototype measurements.