Small‐size wideband chip antenna for WWAN/LTE operation and close integration with nearby conducting elements in the mobile handset

Abstract

A wideband chip antenna having a small size of 3 × 15 × 35 mm3 for application in the mobile handset to cover eight‐band WWAN/LTE operation is presented. The antenna is mainly formed by a direct‐feed two‐branch strip and a coupled‐fed shorted strip. The two‐branch strip functions as an efficient radiator and also as a coupling feed to capacitively excite the shorted strip. The coupled‐fed shorted strip contributes a wide resonant mode at about 800 MHz to cover the LTE700/GSM850/900 (704∼ 960 MHz) operation. The two‐branch strip and the shorted strip together contribute their fundamental or higher‐order resonant modes to cover the GSM1800/1900/UMTS/LTE2300/2500 (1710∼ 2690 MHz) operation. There are also ground planes located on two side surfaces of the chip antenna, which are grounded to the system ground plane printed on the main circuit board of the mobile handset. This configuration allows the antenna to be closely integrated with nearby conducting or electronic elements such as a universal series bus connector to achieve compact integration of the internal antenna in the mobile handset. Details of the proposed antenna are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26200

Small‐size LTE/WWAN coupled‐fed loop antenna with band‐stop matching circuit for tablet computer

“…More variations in the radiation patterns are seen at higher frequencies than at lower frequencies. This behavior is similar to the observations for the internal WWAN/LTE handset antennas [25–30], and is largely because there are more surface current nulls excited in the display ground at higher frequencies than at lower frequencies. This also suggests that although the display ground in the tablet computer does not dominate the radiation patterns of the embedded antenna as the system ground plane in the mobile handset does, the display ground still has large effects on the radiation patterns of the embedded antenna for the WWAN/LTE operation.…”

Small‐size LTE/WWAN planar printed antenna for ultrathin smartphone application

“…The electronic components, including Universal Serial Bus (USB) and microphone, are installed on the surface of the protruded ground plane. Figure shows the measured return loss for the proposed antenna, Ref (the case with a USB connecter), and Ref (the case with a microphone). It is seen that there are very little effects of electronic components on the antenna performance.…”

“… Comparison of measured return loss for the proposed antenna, the case with a USB connecter (Ref ), and the case with a microphone (Ref ). [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com]…”

“…For covering the LTE/WWAN eight communication bands, many technologies have been researched, such as using the coupled feed technology , loading lumped chip elements , loading parallel resonant technology , and reconfigurable technology . However, the 3D structure of the above antennas is not suitable for ultrathin smartphone application.…”

Printed dual‐feed triangular patch antenna disposed in a small notch in the handheld device system ground plane for LTE/WWAN operation

“…To decrease or minimize the antenna's total occupied volume which comprises the antenna's metal pattern and the required isolation space, it becomes attractive that the embedded antennas can be closely integrated with the system ground plane of the handheld device. Some promising WWAN antennas that are capable of close integration with nearby ground plane in the mobile handset have been reported . In Ref.…”