A Novel NFC Antenna for Metal Cover Smartphone Applications

© 2018 IEEE. A miniaturized dual-loop near field communication antenna of size 15 mm×25 mm is proposed for metal cover smartphone applications. By embedded it with a small rectangular slot of size 8 mm×16 mm loaded metal cover, the direction of the eddy current induced on metal cover will be the same with the current flow the on the dual loop NFC antenna coil. It's worth noting that the proposed NFC antenna design was certified by the Europay, Mastercard and Visa (EMV) test

Compact planar zero-ground-clearance end-fire CP antenna with integrated slow-wave structure for mobile terminal applications

202505 bchyVersion of RecordRGCPublishedWiley (2025)T

A Dual-Polarized Shared-Aperture Antenna With Conical Radiation Patterns and High Gain for 5G Millimeter-Wave Ceiling Communications

A dual-polarized (DP) antenna with a conical radiation pattern and high gain characteristics is proposed. It is mainly comprised of a horizontally polarized (HP) array, a vertically polarized (VP) element, a fence, and a feeding network. In the HP direction, a rotatable stacked substrate-integrated waveguide (SIW)-to-coaxial-to-SIW transition (SCST) is meticulously designed to yield omnidirectional radiation with low gain variations and low transmission loss. As for the VP direction, two orthogonal substrates that are arranged above the VP radiating element act as a holder to fix the director, resulting in gain enhancement. Here, the VP element is placed in the center of the HP array to share the aperture for size reduction. Moreover, the top-hat-shaped metal fence collaborates with the large-size ground plane to yield dual conical beams with high gain in DP directions. From the measured results, the HP direction has exhibited desirable bandwidth of 11.4% (24.8-27.8 GHz) with a peak gain of 11.6 dBi, and the VP direction has demonstrated wider bandwidth of 13.7% (24.5-28.1 GHz) with a corresponding gain up to 8.1 dBi. Notably, low gain variations of ±0.65 and ±0.8 dBi are also realized for the HP and VP directions, respectively. Therefore, a DP antenna with high-gain conical beams and low gain variations can be obtained for the fifth-generation (5G) millimeter-wave (MMW) ceiling communications

A Useful Methodology to Convert the Smartphone Metal Cover into an Antenna Booster for NFC Applications

© 1963-2012 IEEE. A useful method to transform the smartphone metal cover into an antenna booster for near-field communication (NFC) antenna installed in a full metal cover (FMC) smartphone is proposed. In this proposed work, by properly embedding a series capacitor into a meticulously selected location within the metal cover, strong coupling between the NFC antenna coil and the metal cover will be generated, which mitigates the reverse eddy current induced on the metal cover. Because of that, the performance of the NFC antenna (located below a narrow horizontal slot-loaded metal cover) is substantially improved, as compared to a reference stand-alone NFC antenna in free-space conditions. To verify this proposed methodology, an ordinary single-turn coil reference NFC antenna 1 (ref 1) and a 3-turn coil reference NFC antenna 2 (ref 2) are initially designed via simulation, followed by the conducting of several typical experiments on these two reference antennas. Finally, the two reference prototype NFC antennas that have utilized this method for a single horizontal slot-loaded FMC are also certified by the Europay, MasterCard, and Visa (EMV) test