Small‐size WWAN monopole slot antenna with dual‐band band‐stop matching circuit for tablet computer application

Abstract

A monopole slot antenna printed on a small‐size FR4 substrate of 40 × 10 mm2 to provide two wide operating bands of 824–960 and 1710–2170 MHz for the wireless wide area network operation in the tablet computer is presented. The monopole slot is folded to achieve a compact configuration and is fed by a microstrip feedline loaded with a dual‐band band‐stop matching circuit on the same FR4 substrate. The band‐stop matching circuit can generate two separate parallel resonances at about 1050 and 2250 MHz, which respectively leads to additional resonance occurred nearby the resonant frequencies of the quarter‐wavelength slot mode at about 850 MHz and higher‐order slot mode at about 1900 MHz, thereby resulting in dual‐resonance excitation of the two excited slot modes to respectively cover the GSM850/900 and GSM1800/1900/UMTS operation. The bandwidth‐enhancement technique of using a dual‐band band‐stop matching circuit is reported for the first time in published articles, and its detailed operating principle is described in this study. Performances of the proposed antenna are also discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:875–879, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26723

Planar small-size LTE/WWAN tablet computer antenna with eight-band operation

“…Additionally, as for the overall antenna volume of only 35 × 10 × 0.8 mm 3 (280 mm 3 ), the proposed antenna has the merit of an antenna size at least 22% less than the smallest dimension of 45 × 10 × 0.8 mm 3 for the LTE/WWAN internal antenna in a tablet computer. [6] Finally, the proposed monopole strip antenna design is more feasible than those above-mentioned ones [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] for embedding into the tablet computers. Moreover, the internal antennas and the user body is less than 20 cm apart in distance during device use.…”

“…ground plane) resonant mode generally not be excited to obtain wider antenna's bandwidth, [20,38,39] especially for lower (LTE700/GSM850/ 900 MHz) band. Several designs have been presented using the lumped LC matching circuit [2,13] to enhance the operating bandwidth or adding a chip component [8,10,12] to make the antenna dimensions more compact. However, due to the additional losses probably incurring from the lumped element in the external matching circuit, the radiation efficiency of the presented antennas [2,8,10,12,13] will be subsequently decreased.…”

“…Several designs have been presented using the lumped LC matching circuit [2,13] to enhance the operating bandwidth or adding a chip component [8,10,12] to make the antenna dimensions more compact. However, due to the additional losses probably incurring from the lumped element in the external matching circuit, the radiation efficiency of the presented antennas [2,8,10,12,13] will be subsequently decreased. To overcome this limitation, a multibranch shorted strip is first introduced to excite triple quarter-wavelength resonant modes close to 750/920/1780 MHz bands in order to comply with the LTE700/GSM850/900/1800 operating bandwidths.…”

“…Therefore, to fulfill the 698-960/1710-2690 MHz bands and suitably embed it into a limited space, a small-size multiband antenna is the most optimal candidate of providing commercial broadband coverage in the bandwidth specifications of the 4G (LTE/ WWAN) system. The various applications of several planar monopole antennas (MAs) developed for LTE/WWAN operations include tablet computers, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] laptop computers [18][19][20], and mobile phones. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] However, those presented antenna designs have the drawbacks in the larger antenna size [3][4][5][6][7][8][9][10] or insufficient operating bandwidth [11][12][1...…”

Planar compact tablet computer monopole antenna for 4G mobile communication system

“…Several planar monopole antennas (MAs) developed for 4G system in tablet computers [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] are presented, however, limited with a bulky dimension. To overcome this limitation, a multi-branch shorted strip is first introduced to generate triple quarterwavelength resonant modes at approximately 750/920/1780 MHz bands in order to comply with the operating bandwidths of 4G mobile system.…”