Internal Compact Dual-Band Printed Loop Antenna for Mobile Phone Application

Multiband Folded Loop Antenna for Smart Phones

“…However, the current variation due to the device being hand-held and the resulting body proximity effect degrades antenna performance since the resonating currents are spread out over the system ground plane [1,10]. To avoid degrading antenna performance, a printed loop antenna is another candidate for the mobile phone since the current induced on the ground plane is small [11][12][13][14][15][16][17].…”

A Compact Planar Hexa-Band Internal Antenna for Mobile Phone

“…Besides keeping the appearances attractive, these devices must be small not only in the plane parallel to the screen but also in the thickness direction for becoming competitive in the market. For attractiveness in appearance, internal antennas that can be completely concealed in the case of a mobile phone are now prevailing over external antennas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. However, the trend for an upcoming mobile phone is that more components need to be installed inside to make the mobile phone more powerful yet possibly smaller in overall size.…”

“…For ease of fabricating mobile handsets, printed internal antennas have been designed to be integrated with ground planes and system circuits on the same substrates [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Since the substrates employed are usually very thin and the conductors printed on them are even much thinner, it is safe to describe antennas of these types only by their widths and heights, without emphasizing their thicknesses.…”

“…These antennas can be divided into four groups. Loop antennas in the first group are operated as a half-wavelength resonant structure [5,6]. Although being able to achieve penta-band operations for GSM 850, GSM 900, DCS, PCS, and UMTS, antennas in this group suffer from the drawback of having a large radiator area (as large as 900 mm 2 ).…”

“…To overcome this disadvantage, some research papers [18][19][20] have proposed printed PIFAs using coupling feeding structures, instead of the direct feeding ones employed in [16,17]. These antenna designs not only can support WWAN or WWAN/WLAN operations but also have smaller antenna heights (i.e., 11, 11, 10 mm for the antennas in [18][19][20], respectively) than those in most of the antennas in [5][6][7][8][9][10][11][12][13][14][15]. Among them, the antenna in [20], although having the smallest antenna height of 10 mm, can support GSM 850/900/DCS/PCS/UMTS/2.4-GHz WLAN hexa-band operations.…”