Chih-Hsien Wu

Ultrawide-band square planar metal-plate monopole antenna with a trident-shaped feeding strip

A square planar metal-plate monopole antenna fed by using a novel trident-shaped feeding strip is presented. With the use of the proposed feeding strip, the square planar monopole antenna studied shows a very wide impedance bandwidth of about 10 GHz (about 1.4-11.4 GHz, bandwidth ratio about 1:8.3), which is larger than three times the bandwidth obtained using a simple feeding strip (about 1.5-3.3 GHz, bandwidth ratio about 1:2.3). In addition, the proposed feeding strip can be integrated with the square planar monopole, that is, the feeding strip and the square planar monopole together can be easily fabricated using a single metal plate, making the proposed antenna easy to construct at a low cost. Details of the experimental and simulation results for the proposed planar monopole antenna are presented and analyzed.

Ultrawideband PIFA With a Capacitive Feed for Penta-Band Folder-Type Mobile Phone Antenna

An ultrawideband planar inverted-F antenna (PIFA) with a capacitive feed in the folder-type or clamshell mobile phone for penta-band operation is presented. The antenna is placed at the hinge position between the main and upper ground planes of the folder-type mobile phone. With the use of the capacitive feed, a very wide operating bandwidth (3:1 VSWR or 6-dB return loss) of about 1.5 GHz (from 820 to 2345 MHz) is obtained, although the antenna is with a small radiating plate of size 8 times 40 mm2 and a low profile of 7.8 mm above the top edge of the main ground plane. The very wide bandwidth covers GSM850/900/1800/1900/UMTS penta-band operation for the mobile phone in the open (talk) state. In addition, when in the closed (standby) state, although the groundplane condition greatly differs from that in the open state, the impedance matching over the operating bands can still be better than 6:1 VSWR (3-dB return loss), acceptable for standby operation in the practical applications.

User's hand effects on EMC internal GSM/DCS mobile phone antenna

The users hand effects on the EMC GSM/DCS antenna embedded in the mobile phone have been presented. Although the EMC antenna is easy to be integrated into a mobile phone with nearby electronic components or conducting elements, the performance of the antenna is still greatly affected when a users hand holds the mobile phone. Even when the phone was hand-held at the bottom, large efficiency drops have been observed, especially for the GSM operation

Wide-band omnidirectional square cylindrical metal-plate monopole antenna

A novel square cylindrical monopole antenna easily fabricated from bending a cross-shaped metal plate for wide-band omnidirectional operation is presented. With a cross-sectional area of 8 /spl times/ 8 mm/sup 2/ and a length of 23 mm, the antenna can provide a wide operating bandwidth of about 4.7 GHz (about 1.9 /spl sim/ 6.6 GHz), making it very promising for WMAN operation with the 802.16e standard in the 2 to 6 GHz band. In addition, over the operating bandwidth, the antenna shows very good omnidirectional radiation (gain variations less than 1.5 dB in the azimuthal plane over the bandwidth). Experimental and simulation results of the proposed antenna are presented and discussed.

Conformal bluetooth antenna for the watch-type wireless communication device application

A promising conformal Bluetooth monopole antenna in the watch-type wireless device has been proposed. The proposed antenna is short-circuited to an upper ground plane mounted above the system ground plane. Results have indicated that, with the proposed arrangement, the radiation efficiency can reach about 50% over the band with the presence of the users forearm. In addition, the antenna shows a low profile of 4 mm only, and the thickness of the wireless device can be about 10 mm only, which makes it very promising and attractive to be worn around the users wrist or forearm for practical applications.

Low-profile printed monopole antenna for penta-band operation in the mobile phone

A printed monopole antenna for penta-band operation in the mobile phone is proposed and studied. The antenna has a uni-planar structure and can be easily printed on an inexpensive FR4 substrate with a low cost. The antenna occupies a small area of 45 x 100 mm , yet it can generate two wide bands centered at about 900 and 2000 MHz to cover AMPS/GSM/DCS/PCS/UMTS operation. Good radiation characteristics of the antenna over the operating bands is observed. The proposed antenna is very promising for application in the mobile phone as an internal antenna for penta-band operation.

Simplified hand model for the study of hand-held device antenna

This paper proposes a one-layer simplified hand model incorporating the use of 3D FDTD simulation software, SPEAG SEMCAD-X (simulation platform for EMC, antenna design, and dosimetry) for achieving efficient simulation for hand-held device antennas. The case of the GSM/DCS internal mobile phone antenna with the proposed hand model is first presented. Effects of the proposed hand model including the users forearm on the impedance and radiation characteristics of the internal antenna are analyzed. A second case of the DTV antenna in the PMP device with proposed hand model is also studied

Ultra-wideband PIFA with a capacitive feed for penta-band operation in the folder-type mobile phone

A novel planar inverted-F antenna with a capacitive feed to generate a very wide operating band for penta-band operation in the folder-type mobile phone has been proposed. The antenna is simple in geometry and occupies a compact volume to allow it to be easily embedded inside the housing of the mobile phone to operate as an internal antenna. For both the open (in-use) and close (standby) states of the folder-type mobile phone, the obtained bandwidth of the antenna can cover GSM850/900/1800/1900/UMTS operation. Good radiation efficiency over the operating band has also been obtained.

Thin Internal GSM/DCS Patch Antenna for Mobile Phones

A thin internal patch antenna with an air-layer substrate thickness of 4 mm only for GSM/DCS operation has been proposed. The enhanced bandwidths of the antenna are obtained by adding a widened end portion to the longer resonant path and a tapered end portion to the shorter resonant path, which are expected to result in more smooth surface current distributions in the end portion of the antennas two resonant paths, thereby leading to bandwidth enhancement. With its thin profile, the antenna is very promising for thin mobile phone applications