Search

This paper describes an ultrahigh frequency (UHF) tag antenna mounted on a metallic plate for radio frequency identification (RFID). The impedance of the proposed antenna can be tuned using various methods. The compact patch antenna consists of a C‐shaped resonator and a ground plane connected to a small shorting wall and is connected to a feeding loop in the middle of the C‐shaped resonator. Etching a couple of slits close to the shorting wall and a slot in the center of the C‐shaped resonator provided a flexible method for adjustment to match the conjugate impedance with the UCODE 8/8 m chip (13 − j191 Ω at 915 MHz). The optimal design with an overall size of 30 × 30 × 3 mm3 (0.092 λ0 × 0.092 λ0 × 0.0092 λ0) yielded a high power transmission coefficient of 91% and reading range of 6.4 m for the effective isotropic radiated power (EIRP) of 4.0 W when the tag antenna was mounted on a 220 × 220 mm2 metal plate. The proposed antenna was designed at standard frequency bands of the Federal Communications Commission (FCC, 902‐928 MHz) for North America and Taiwan. Antenna fabrication and testing were performed, which revealed that the measured data were in good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

In this study, multi‐band antenna for LTE wearable device with shared slots and radiators for smart watch was present. This study incorporated 4G communication frequency bands, a GPS positioning system, and BT/Wi‐Fi in a 43.6 × 43.6 × 5.8 mm3 metal case to achieve satisfactory radiation fields and performance efficiency within a small space. This article presents an overview of the theory. There are four ports in the system. Frist, Port 1 is a low‐frequency antenna offering LTE 700 and GSM 850/900. The maximal gain and efficiency are respectively 3.9 dBi and 82%. Second, Port 2 is a high‐frequency monopole with a winding long path on the side of the frame to achieve a reflection loss bandwidth that fully encompasses GSM 1800/1900/UMTS and LTE 2300/2500. The maximal gain and efficiency of this port are respectively 5.3 dBi and 92%. There are also have GPS (Port 3) and Wi‐Fi (Port 4) antenna implement IFA and loop excitation mechanisms, respectively. This antenna system can fulfill the market demand. As confirmed through both simulation and measurement, the antenna can cover LTE bands. Increasing the path capacity of a MIMO system to increase the transmission speed is a crucial focus in mobile communication research and development. [ABSTRACT FROM AUTHOR]

Dual open‐slot antennas were integrated in the metal back case and metal frame of a tablet computer for long‐term evolution applications. The single feed dual excitation source antennas were sufficiently narrow (2 mm) for installation between the metal frame and metal back case of the tablet computer. Each antenna had two open‐slot radiators (slot 1 and slot 2) with embedded filter circuits to enable wideband (699‐906 and 1710‐2690 MHz) operation required for LTE applications. The filter circuit values were adjusted to make the impedance more smooth and excite the desired modes. The proposed multiple‐input‐multiple‐output antennas were installed lengthwise on the long sides of the tablet and facing in operate directions. In this configuration, the user hand grip did not interfere with antenna performance, and isolation was improved (> 20 dB). The operating mechanism of the proposed antenna with matching circuits is described in detail. The effects of the user hand grip and the embedded display panel are also discussed. [ABSTRACT FROM AUTHOR]