Lasser, G., Mayer, L. W., Popovic, Z., & Mecklenbräuker, C. (2016). Low-Profile Switched-Beam Antenna Backed by an Artificial Magnetic Conductor for Efficient Close-to-Metal Operation. IEEE Transactions on Antennas and Propagation, 64(4), 1307–1316. https://doi.org/10.1109/tap.2016.2526044
Electrical and Electronic Engineering; efficiency; Antennas; metamaterials; beam steering; frequency selective surfaces; radio-frequency identification
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Abstract:
This paper presents a compact switched-beam antenna (SBA) mounted on the bottom of a car. The antenna and associated circuits read RFID data sensed directly from all four tires. The frequencies of interest are the European UHF RFID band (866 MHz) and the 2.45 GHz ISM-band. In both cases, the antenna is electrically close to the conductive floor of the vehicle. In order to improve performance, dual-band periodic printed surfaces are designed and the efficiency, pattern, and loss are characterized for the antenna mounted above the FSS. In the UHF-band, the size of the assembly is 0.87λ0 × 0.87λ0 × 0.11λ0 and its performance is not sensitive to the position of the conductive car bottom surface. The antenna over FSS assembly has a directivity of 5.6 dB and the efficiency is enhanced by a factor of 2.35 (3.7 dB).
