Planar strip monopole with a chip‐capacitor‐loaded loop radiating feed for LTE/WWAN slim mobile phone application

Abstract

The radiation performance of a single feed circularly polarized stacked arrangement of edge truncated elliptical and conventional circular patches is presented in this communication and results are compared with that of a single layered edge truncated elliptical patch antenna. Though the single feed single layer edge truncated elliptical patch antenna presents circular polarization but its axial ratio bandwidth, impedance bandwidth and gain are low. Therefore this geometry is modified in this communication and a two layered stacked arrangement is proposed with much improved performance. By considering present arrangement, both impedance bandwidth and gain of antenna are improved to a great extent. Circular polarization with improved axial ratio bandwidth is achieved with present arrangement. The reported impedance bandwidth and axial ratio bandwidth are 27.9 and 3.33%, respectively which are significantly higher than that of conventional or edge truncated elliptical patch antenna geometry. The obtained results suggest that proposed antenna with little more improvement may become very useful for modern communication systems. ACKNOWLEDGMENTSThe authors thank Dr. S. Pal and Mr. V.V. Srinivasan from ISRO, Bangalore for permitting to use available facilities at ISRO, Bangalore. They also thank Mr. Shivareddy and Mr. Pawan Kumar for their help in testing of designed antennas. ABSTRACT: A small-size wideband internal mobile phone antenna formed by a planar strip monopole with a chip-capacitor-loaded loop radiating feed for achieving eight-band long term evolution/wireless wide area network operation in the 698-960 and 1710-2690 MHz bands is presented. The antenna is suitable to be disposed on a small noground board space (15 Â 45 mm 2 ) of the system circuit board and enclosed by an L-shaped system ground plane of the mobile phone. On the protruded ground of the L-shaped system ground plane, a universal series bus connector for the data port of the mobile phone can be accommodated without affecting the antenna performances. The antenna also shows a low profile of 3 mm above the circuit board, which makes it very promising for slim mobile phone applications. The proposed antenna was fabricated and tested. Measured and simulated results are presented. The specific absorption rate results of the antenna are also analyzed. Owing to the recent introduction of the long term evolution (LTE) operation [1] for mobile broadband services, the mobile devices such as the notebook computers and mobile phones in the near future are expected to be capable of both the LTE and wireless wide area network (WWAN) operations. For this application, the internal antenna in the mobile device should provide two wide operating bands of at least 698-960 and 1710-2690 MHz to cover three LTE bands (LTE700/2300/2500 in the 698-787/2300-2400/2500-2690 MHz bands) and five WWAN bands (GSM850/900/1800/1900/UMTS in the 824-894/880-960/1710824-894/880-960/ -1880824-894/880-960/ /1850824-894/880-960/ -1990824-894/880-960/ /1920824-894/880-960/ -2170. Sever...

Printed multi-resonant antenna embedding two inductors in radiating strips for internal mobile phone LTE/WWAN operation

“…However, these antenna designs [3,5,6,9,18] are unable to cover the emerging long-term evolution (LTE700/2300/2500 MHz) operating bands, which are attractive for obtaining higher data transmission and more abundant multi-media services than the GSM and UMTS mobile networks. Moreover, with 3D folded/bent metal-plate structures [4,9,14,19], the reported antennas' height hinders their abilities to integrate with RF (radio frequency) or MMIC (Monolithic Microwave Integrated Circuit) modules in the thin mobile handset application.…”

“…In the feeding structure, the conventional direct-fed antennas [1][2][3] are difficult to achieve dual broad bandwidths. A more effective feeding method is capacitively coupled feed [4,5,9,14,19], which can result in an improved impedance matching over the desired operating band [4,14] mainly in the 900 MHz to cover the desired lower band of 698-960 MHz. In [4], a small-size (15 Â 45 Â 3 mm 3 ) wideband internal mobile phone antenna formed by a planar strip monopole with a chip capacitor loaded for achieving eight-band LTE/WWAN operation has been proposed.…”

“…The internal antennas that can cover the eight-band LTS/GSM/UMTS WWAN operation are, therefore, preferred for the mobile phone application. Recently, some promising designs have been proposed and studied in the open literature [3][4][5][6][7][8][9][14][15][16][17][18][19][20]. However, these antenna designs [3,5,6,9,18] are unable to cover the emerging long-term evolution (LTE700/2300/2500 MHz) operating bands, which are attractive for obtaining higher data transmission and more abundant multi-media services than the GSM and UMTS mobile networks.…”

“…Providing more diversified services for mobile users by only one antenna is promising, which in turn leads to the increasing investigation in designing a single antenna that can operate in different bands of interest [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Generally speaking, these desired operating bands include the 2G (GSM850/900/DCS1800/PCS1900), 3G (UMTS2100), and 4G (LTE700/2300/2500) for practical mobile phone terminals in the near future.…”

“…An effective method among them is the use of the lumped chip elements loaded in radiating strips [3,4,9,14,18]. In the feeding structure, the conventional direct-fed antennas [1][2][3] are difficult to achieve dual broad bandwidths.…”