Bandwidth Enhancement of Small-Size Planar Tablet Computer Antenna Using a Parallel-Resonant Spiral Slit

A Coupled-Fed Reconfigurable Antenna for Internal Lte Mobile Phone Applications

“…A parasitic antenna was proposed in [8], and the antenna consisted of a feed monopole and a short stub, with a coupling aperture for matching adjustment, so the antenna achieved a wide band. Furthermore, the space left for antenna design is getting smaller and smaller, several scholars proposed using impedance matching circuit at feeding port to obtain broadband coverage [9][10][11][12]. RF switch is also used to design a reconfigurable antenna to achieve a wide band by combing several different statuses.…”

A Tunable Multiband Lte Antenna for Metal-Rimmed Smartphone Applications

“…However, its biggest drawbacks of the antennas are narrowband and too much space of the PCB (clearance area) occupied. Furthermore, because the space left for antenna is getting smaller and smaller, several scholars proposed using impedance matching circuit at feeding port to obtain broadband coverage [6][7][8][9]. RF switch is also used to design a reconfigurable antenna to achieve a wideband by combing several different statuses.…”

“…The bandwidth can completely cover 824-960 and 1710-2690 MHz. So the proposed antenna can work at GSM850, 900; DCS1800; PCS1900; WCDMA band 1, 2, 4, 5, 8; TD-SCDMA band 34, 39; CDMA BC0, BC1 and LTE band 1,3,7, 38, 39, 40, 41. Also, the total size of the cellphone is 150 mm × 75 mm × 3.5 mm, which is very suitable for 4G slim smart mobile phone applications.…”

Two-Strip Narrow-Frame Monopole Antenna With a Capacitor Loaded for Hepta-Band Smartphone Applications

“…Until now, various types of technologies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have been proposed for multi-band smartphone applications, such as loaded lumped chip elements [4,5], distributed inductive strips [6,7], coupled-fed feeding [8][9][10][11][12][13], LC matching circuits [14][15][16], parallel resonant structures [17,18] and reconfigurable antennas [4,19,20]. All these technologies can reduce the sizes of the antennas and enhance the operating bandwidth.…”