A miniaturized multifrequency antenna is proposed. The proposed antenna can generate three separate impedance bandwidths to cover all the 2.4/5.2/5.8-GHz WLAN operating bands and the 2.5/3.5/5.5-GHz WiMAX bands. The proposed microstrip-fed antenna mainly consists of a circular ring, a Y-shape-like strip, and a defected ground plane. By adding a Y-shape-like strip in the circular ring, the antenna excites two resonant modes and is with miniaturization structure. Because of the introduction of the cambered ground plane with an isosceles triangle-defect, the third wide band with better impedance matching is obtained. A prototype is experimentally tested, and the measured results show good radiation patterns and enough gains across the operation bands.

Miniaturized Triple-Band Antenna With a Defected Ground Plane for WLAN/WiMAX Applications

A coplanar waveguide (CPW)-fed planar monopole antenna with triple-band operation for WiMAX and WLAN applications is presented. The antenna, which occupies a small size of 25(L) × 25(W) × 0.8(H) mm3, is simply composed of a pentagonal radiating patch with two bent slots. By carefully selecting the positions and lengths of these slots, good dual stopband rejection characteristic of the antenna can be obtained so that three operating bands covering 2.14-2.85, 3.29-4.08, and 5.02-6.09 GHz can be achieved. The measured results also demonstrate that the proposed antenna has good omnidirectional radiation patterns with appreciable gain across the operating bands and is thus suitable to be integrated within the portable devices for WiMAX/WLAN applications.

Novel CPW-Fed Planar Monopole Antenna for WiMAX/WLAN Applications

A low profile printed antenna with triple band operation is presented for simultaneous use in wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The antenna consists of a rectangular radiating element fed asymmetrically by a 50 Ω microstrip line and a shaped trapezoidal ground plane. Rectangular horizontal strips are attached to the radiation element to form different current paths which make the antenna resonate in WLAN and WiMAX frequency bands. The antenna operates in dipole configuration outlining overall dimensions of 38×30×0.8 mm3.

Compact triple band antenna for WLAN/ WiMAX applications

A multiband printed monopole slot antenna promising for operating as an internal antenna in the thin-profile laptop computer for wireless wide area network (WWAN) operation is presented. The proposed antenna is formed by three monopole slots operated at their quarter-wavelength modes and arranged in a compact planar configuration. A step-shaped microstrip feedline is applied to excite the three monopole slots at their respective optimal feeding position, and two wide operating bands at about 900 and 1900 MHz are obtained for the antenna to cover all the five operating bands of GSM850/900/1800/1900/UMTS for WWAN operation. The antenna is easily printed on a small-size FR4 substrate and shows a length of 60 mm only and a height of 12 mm when mounted at the top edge of the system ground plane or supporting metal frame of the laptop display. Details of the proposed antenna are presented and studied.

Multiband Printed Monopole Slot Antenna for WWAN Operation in the Laptop Computer

Planar ultrawideband (UWB) antennas with on-ground band-notched structures are studied in this paper. Two different slot resonators, which feature quarter-wavelength and half-wavelength configurations, are embedded into the arc shaped ground plane of the circular disk patch antennas in order to obtain the desired band-rejection around 5.8 GHz. Their principles and characteristics are analyzed and compared in detail providing designers with in-depth understanding and useful design information. By choosing the quarter-wavelength slot resonator, the first spurious stopband can be pushed up to 3 f 0 (f 0 stands for the center frequency of the notch) and this antenna retains a super wide working band which spans from 1.62 GHz to 17.43 GHz. Performance in both the frequency domain and time domain for this antenna has been investigated carefully. The transmission response of a transceiving antenna system and their corresponding transient analysis are discussed at the end of this paper.

Analysis of Planar Ultrawideband Antennas With On-Ground Slot Band-Notched Structures

The band-rejected designs of the printed open slot antenna for wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications are investigated. First, the broadband characteristic (2.3 ~ 6uarr GHz) of open slot antenna design with small size is implemented and measured. Then, inserted a single strip on the broadband antenna is studied and investigated. By inserting a strip on the printed open slot of the broadband antenna, to reject frequency from 3.56 to 4.58 GHz, a dual-broadband design of the open slot antenna with small size is obtained for WLAN applications in the 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) bands. Furthermore, by inserting two strips of different length on the open slot antenna, a three-band antenna is achieved. By adjusting the dimension of two strips on open slot antenna, a three operating modal frequencies at 2.37 ~ 2.72,3.31 ~ 3.78, and 4.5 ~ 5.97 GHz for WiMAX application have been obtained. Detailed design steps and experimental results for the designs are studied and investigated in this paper.

Wen-Shan Chen

Papers

Band-Rejected Design of the Printed Open Slot Antenna for WLAN/WiMAX Operation