Wideband Low‐Directivity Antennas Using Cavity Structure for Tablet and Laptop Computer Applications

ABSTRACT

In tablet and laptop computer applications, there is a growing demand for wideband, wide‐coverage, and low‐directivity antennas. To accommodate tablet and laptop environments, antennas need to be easily integrated and typically have a large ground. There is limited research on wideband and low‐directivity antennas for tablet and laptop computer applications, especially under the constraint of a large ground. This communication proposes a novel method to design low‐directivity antennas for tablet and laptop computers with a large ground. The proposed antennas contain two resonant cavities and a power‐divided feed network. Two orthogonal resonant cavities are introduced to excite two complementary radiation patterns. A power‐divided feeding network provides the same amplitude and phase excitation to two resonant cavities. Two resonant cavities have different dimensions to improve the impedance bandwidths. In order to solve the problem of the radiation performance deterioration under the laptop computer operating state, an effective method has been proposed to optimize the proposed antenna structure. Finally, the proposed two antennas are fabricated and measured. The proposed two antennas are operating at a wireless local area network (WLAN) band with a profile of 6.1 mm. The tablet antenna with an impedance bandwidth of 5.14–5.94 GHz and a total efficiency more than −1 dB are obtained. The other laptop computer antenna with the impedance bandwidth of 5.13–5.93 GHz and a total efficiency more than −1 dB are obtained. The proposed antennas have the advantages of high performance, simple structure, and easy integration, which exhibit great potential in tablet and laptop computer applications.