Metamaterial-Loaded Multiband Antenna For Embedded Automotive Internet-Of-Things Communications

This study presents the design of a multiband monopole antenna using the metamaterial (MTM) loading technique for embedded automotive Internet-of-Things (IoT) communications. The proposed antenna consists of a simple microstrip line monopole loaded with a novel E-slotted MTM. The unit cell MTM consists of a central transmission line loaded with parasitic patches that are deployed with "E"-shaped slots. The MTM is symmetrically loaded to either side of the monopole antenna to achieve miniaturization through frequency reduction and to realize multiple resonances. The proposed monopole antenna has a footprint of 10 x 30 mm(2) and operates at 2.45, 3.3, and 3.8 GHz suitable for Industrial Scientific and Medical applications (ISM), Wireless Fidelity (WiFi), and Worldwide Interoperability for Microwave Access (WiMAX) applications that are exploited in IoT communications. The prototype antenna is fabricated, and the simulation results are validated using experimental measurements. The prototype antenna offers the measured impedance bandwidth of 6%, 7%, and 10% at the said frequencies. The measured gain of the antenna is greater than 3.2 dBi, and the simulated efficiency is close to 86% throughout the operating bandwidth. The performance of the proposed antenna in the vicinity of the vehicle is tested, and the results are presented.