Integration of monopole slot and monopole strip for internal WWAN handset antenna

Abstract

Abstract A novel internal handset antenna formed by a monopole slot and a monopole strip for the wireless wide area network (WWAN) operation in the 824–960 and 1710–2170 MHz bands is presented. The monopole strip is disposed in the monopole slot, and both are embedded in the system ground plane of the handset with a small board space of 9 × 40 mm 2 at about the bottom edge of the circuit board. The monopole strip serves as a feed for the monopole slot and also functions as an efficient radiator. In the proposed design, the monopole slot generates a quarter‐wavelength slot mode in the antenna's lower band, while the monopole strip contributes its quarter‐wavelength mode in the antenna's upper band. By including a vertical strip that can be enclosed inside the handset casing or be a part of the bezel surrounding, the periphery of the handset casing and connected to the bottom edge of the system ground plane, the impedance matching of the excited slot mode can be greatly improved. In this case, the proposed antenna can provide two wide operating bands with good impedance matching to cover the pentaband WWAN operation. Detailed operating principle of the integrated monopole slot and monopole strip for the internal WWAN handset antenna is described. The proposed antenna is also fabricated and obtained results are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1718–1723, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26870