Longyue Qu

Mode-Controlled Wideband Slot-Fed Ground Radiation Antenna Utilizing Metal Loads for Mobile Applications

In this communication, we introduce a mode-controlled ground radiation antenna comprised of a resonance-controlled ground plane and a nonradiating feeding slot for wideband applications in mobile devices. A 110 mm

High-Sensitivity Ground Radiation Antenna System Using an Adjacent Slot for Bluetooth Headsets

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Two-layered ground radiation antenna for high efficiency applications

mm ground plane for 850-MHz operation is studied as a test case. The resonant frequency of the ground plane is lowered by adding metal loads at the top and bottom intended for strong coupling with a miniature feeding slot located at one end, so that the ground plane is resonant as a half wavelength dipole-type radiator. The metal loads can be the structures of strips, plates, or wires, and they can take the form of broken metal rims or frames with cuts or gaps in smartphones. In addition, the metal loads are connected to the ends of the ground plane by lumped elements (inductors and/or capacitors) for easy control of the resonance mode and compact design. Equivalent circuit model and corresponding equations are provided for theoretical analysis. The impedance bandwidth based on 3:1 VSWR is 210 MHz (from 760 to 970 MHz), with an average efficiency of 77%. Geometrical characteristics of the metal loads are shown to be important parameters for the antenna performance.

Miniaturized quadruple-band ground radiation antenna for mobile devices

In this communication, we introduce a high-sensitivity antenna system for Bluetooth headsets dealing with the numerous and unidentified noises in a printed circuit board (PCB). This antenna system is composed of a ground radiation antenna for Bluetooth applications and an adjacent slot for noise suppression. A loop-type circuit is used to model a noise source on the PCB to provide wide-frequency spectrum noise currents to analyze the noise performance of the high-sensitivity antenna system. Decoupling between the noise sources and the antenna port can lead to high sensitivity. An adjacent slot is designed as part of the system to improve the sensitivity, based on the decoupling theorem. This proposed system is effective and applicable for high-sensitivity antenna design, as verified through simulation and active measurements of Bluetooth headsets.

Compact dual-band antenna using inverted-L loop and inner rectangular loop for WLAN applications

In this paper, a novel technique is proposed that is applicable to cases in which two-layered ground planes exist to achieve high radiation performance. The proposed ground radiation antenna is composed of a radiating loop and a feeding loop, which are built into separate two-layered ground planes. The feeding loop and radiating loop are located on the small top-layer ground plane and the large bottom-layer ground plane, respectively, so that two loops are magnetically coupled to each other, and the large bottom-layer ground plane is then excited as a radiator. The reference antenna is built with a radiating loop and a feeding loop only on the top-layer ground plane. High performances are achieved both in simulation and measurement.

Performance enhancement of ground radiation antenna for Z-wave applications using tunable metal loads

A miniaturized quadruple-band ground radiation antenna within a small clearance of 7 mm × 10 mm × 1 mm is proposed for 1.575 GHz GPS band, 2.4 and 5 GHz Wi-Fi bands, as well as 3.5 GHz WiMAX band in mobile devices. The −6 dB (VSWR < 3) impedance bandwidths of 38, 121, 114, and 542 MHz are achieved, covering the GPS band, Wi-Fi 2.4GHz band, WiMAX 3.5GHz band, and Wi-Fi 5 GHz band, respectively.