Research On Techniques Of Narrow Frame LTE Antenna For Smartphone Applications

In recent decades, with the rapid development of the mobile communication and modern electronic technology, mobile communications industry is growing at a very rapid pace of development in every country around the world. At the same time, the mobile terminal, which has the function of communication, has undergone decades of development. The mobile terminal is transforming from a simple communication tool to a terminal with integrated information processing platform, which is called intellectualized. Mobile phone which is on of the fastest-growing of has been the most popular mobile terminals all around the world. It has gradually and deeply impact on people’s daily lives and has become an essential part of life and work. The mobile antenna, which is one of the important components of smartphone, will directly decide the performance of the mobile phone system. Hence, it is significant to study and design some LTE antennas with high performance.First, this paper introduces the development process of the mobile communication system, mobile phone and the mobile antenna. The antenna’s basic theory, common types of mobile antenna and the technologies of miniaturization and broadband are presented.Then, it has proposed a novel coupled-fed antenna design with a character of narrow-frame, occupying a size of 5×40 mm2. The greatest highlight of this proposed antenna is that its narrow edge has a width of only 5 mm, which is very novel for smartphone applications and provides a great idea for future antenna design. Moreover, this proposed antenna can provide two wide operating bands of 824–960 and 1710–2690 MHz, respectively, based on standard of VSWR≤3:1.Further, it has presented a novel directed-fed narrow-frame antenna under surroundings of an unbroken metal rim in smartphone applications. Two no-ground portions of 10×70 mm2 and 5×70 mm2 are set on the top and bottom edge of the system circuit board, respectively. In-between the two separate no-ground portions, there is a system ground plane with the length of 115 mm and the width of 70 mm. The unbroken metal rim with 5 mm in height is very popular for slim smartphones. By combining the multi-resonant character of the dual-loop antenna, the proposed antenna can provide two wide operating bands covering WWAN/LTE seven operation bands.Finally, it has presented a novel coupled-fed narrow-frame antenna under surroundings of a metal rim with a slot(width of 1 mm) in smartphone applications. The width of narrow edge of the proposed antenna is only 5 mm. Based on SRR, this proposed antenna by utilizing the reconfigurable technology can cover WWAN/LTE seven operation bands.