Uniplanar coupled‐fed printed PIFA for WWAN operation in the laptop computer

Abstract

In this article, a uniplanar printed PIFA (planar inverted‐F antenna) with a coupling feed for application as an internal laptop computer antenna for penta‐band WWAN (wireless wide area network) operation is presented. The proposed PIFA has a compact structure and can be easily printed on one side of a small 0.8‐mm thick FR4 substrate of size 11 × 59 mm2, making it very promising to be embedded inside the casing of the laptop computer, especially for the thin‐profile laptop computer. With the coplanar coupling feed, the large inductive input reactance of the PIFA at around 900 MHz is compensated, and dual‐resonance excitation for the antenna's lower band at about 900 MHz is obtained, which allows it to easily cover GSM850/900 operation. A wide operating band is also achieved for the antenna's upper band at about 1900 MHz, and a bandwidth of larger than 500 MHz is obtained to cover GSM1800/1900/UMTS operation. That is, the proposed PIFA covers all the five operating bands of GSM850/900/1800/1900/UMTS for WWAN operation. Details of the proposed PIFA are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 549–554, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24084

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.…”

“…However, a height of 15 mm may be regarded as too large for some mobile handsets. In the fourth group are printed planar inverted-F antennas (printed PIFAs) [16][17][18][19][20], whose operations also rely on quarter-wavelength resonance. A simple printed PIFA can be constructed by adding a grounded strip to an inverted-L quarter-wavelength monopole [16,17].…”

“…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.…”

“…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. However, the antenna width of 60 mm for the antennas in [16,18] may be considered large for some handsets.…”