Novel conformal automotive di-patch antenna verified through car door frame measurements

摘要

The increasing number of wireless automotive applications demand innovative antenna solutions in line with the aesthetics of passenger cars. The antennas should be low-profile, conformal, metal surface tolerant, and provide sufficient gain and operational frequency bandwidth. The di-patch is a novel differentially-fed antenna that fulfils these requirements. This paper highlights the key design considerations and advantages of a di-patch antenna over typical patch antennas, moving on to the simulation and measurement results of a 1.6 mm thick FR4 (ε_r=4.35, tanδ=0.023) based 2.45 GHz di-patch antenna embedded in the B-column plastic cover of a car, wherein the influence of the plastic embedding and the door frame on the antenna performance are also addressed. The peak simulated and measured realized gains were 5 dBi and 3.5 dBi respectively, while the simulated and measured total efficiencies (including matching losses) were 56% and 35% respectively. Given that the antenna is subject to pressures of up to 140 MPa, and temperatures as high as 240°C during the injection moulding process, the results are promising, making di-patch an attractive candidate for use in automotive wireless applications.