Abstract-A novel compact microstrip planar slot antenna with triple-band operations for WALN and WiMAX applications is proposed. The antenna, which occupies an overall dimension of 35 × 19 × 1.6 mm 3 , has a simple structure which consists of an asymmetric coplanar strip with a reverse G-shaped slot and a Ushaped open stub. The U-shaped open stub excites a resonant mode at 2.4 GHz. On the other hand the asymmetric coplanar strip could excite the resonant modes at 5.2 GHz. Meanwhile, the reverse Gshaped slot is aimed to excite resonant modes at 3.5 and 5.8 GHz. It has good omnidirectional radiation patterns in the azimuth plane and reaches 1.1 dBi at 2.4 GHz, 2.3 dBi at 3.5 GHz, 3.1 dBi at the band of 5 GHz. The designed antenna is simulated by HFSS software and a good agreement with experimental results is demonstrated.

Abstract-A novel CPW-fed antenna having a frequency bandnotched function for UWB applications is proposed and studied. By inserting a pair of inverted-T-shaped slots on the radiation element, the narrow frequency band notch has been created to cover the desired frequency varying from 3.4 to 3.69 GHz and the required UWB bandwidth is also acquainted. Good monopole-like radiation patterns and antenna gains have also been obtained.

A novel printed antenna having a frequency band‐notched function for UWB applications is proposed and studied. With a pair of inverted‐L‐shaped slots introduced around the microstrip line on the ground, a frequency‐notched response at 5.2 GHz is obtained. The designed antenna satisfies the VSWR requirement of less than 2.0 in the frequency band between 2.8 and 10.7 GHz while showing the band rejection performance in the frequency band from 4.8 to 5.7 GHz. Good monopole‐like radiation patterns and antenna gains have also been obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 260–263, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24003

This paper presents a two-dimensional low-profile Luneburg lens that is designed by using a glide-symmetric metasurface. The entire lens consists of two mirrored metal plates with periodic metal pins, and the pins on one plate are glided exactly a half period of the unit cell compared with the pins on the other plate. The proposed design has not only a stable refractive index over a wide operating band but also no dielectric loss compared to other metamaterial-based lenses. In addition, it is easy to manufacture and can also largely reduce the production cost. The complete Luneburg lens is simulated in CST Microwave Studio, and the results demonstrate that the lens can work within 14 GHz-22 GHz, which is greater than 44% of the bandwidth. The measured results show that the lens also agrees well with the simulated lens. This lens antenna would be an excellent candidate for satellite communication applications.

path to the original loop strip, and excites the 0.5-, 1.0-, and 1.5-wavelength modes of the two loops successfully. These excited resonant modes are formed into two wide operating bands for the antenna's lower and upper bands to cover GSM850/900 and GSM1800/1900/UMTS/WLAN/WiMAX operations. Good radiation characteristics over the seven operating bands have also been obtained. In addition, the antenna occupies a small volume of 60 ϫ 10 ϫ 3 mm 3 (1.8 cm 3 ) only, with a thin thickness of 3 mm. It is also promising to reduce the thickness to 2 mm only, which can further decrease the occupied antenna volume to be 1.2 cm 3 . The small volume and thin thickness make the proposed antenna very suitable for thin mobile phone applications. REFERENCES1.

Abstract-A coplanar waveguide (CPW)-fed planar monopole antenna with triple-band operation for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) applications is presented. The antenna comprises dual rectangular ring with open-end. The triple operating bands with 10-dB returnloss bandwidths of about 30.8% ranging from 2.2 to 2.97 GHz, 23.4% ranging from 3.17 to 3.99 GHz, and 25.4% ranging from 4.91 to 6.31 GHz, covering the required bandwidths of 2.4/5.2/5.8 GHz WLAN and 3.5/5.5 GHz WiMAX standards, are obtained.

ABSTRACT:A compact and simple monopole antenna with CPW-fed structure is proposed for application in dual-band WLAN systems. The proposed antenna, which resembles the shape of the letter "e", has a compact size of only 27 ϫ 18 ϫ 1.6 mm 3 including the ground. By fabricated and measured, the proposed antenna covers both 2.4 and In this letter, we present a novel compact CPW-fed antenna resembling the shape of the letter "e" to satisfy for 2.4/5 GHz WLAN applications (2.4 -2.484 GHz for IEEE 802.11b/g and 5.15-5.825 GHz for IEEE 802.11.a). Compared with those reported, the proposed antenna has simple structure and compact size, moreover, can provide good monopole-like radiation patterns for both bands. Details of the antenna design are described, and both simulated and measured results are presented. ANTENNA DESIGNThe geometry and dimensions of the proposed antenna for dualband WLAN operations is shown in Figure 1. For the design studied here, the antenna is fabricated on the FR4 substrate of relative permittivity r ϭ 4.4 and substrate thickness h ϭ 1.6 mm, . The antenna is fed by a 50 ⍀ CPW transmission line, which consists of a signal strip width of 3.6 mm and a gap distance of 0.4 mm between the single strip and the coplanar ground plane. The dual-band operation of the proposed antenna is achieved by the dual resonant structures. As shown in Figure 1, the two resonant paths for 2.4 and 5 GHz bands are the whole path of the proposed antenna and path1, respectively. In addition, the very monopole-like radiation patterns for 5 GHz band can be obtained by the approximate symmetry of the path1 with respect to the x-direction. The parameters of the proposed antenna are designed by using Ansoft's high frequency structure simulator (HFSS). The measured antenna is connected to the cable by a coaxial SMA connector, which is taken into account in the simulation. RESULTS AND DISCUSSIONThe proposed antenna has been constructed and experimentally studied. The simulated and measured return losses obtained by using Ansoft's HFSS and Aglient8363B vector network analyzer, respectively, are shown in Figure 2, together with the simulated one for the antenna with path1 only. From the curves (i) and (iii) in Figure 2, it is seen that dual resonant modes are excited by the path1 and the whole path of the proposed antenna, respectively. In the 2.4 GHz band, the measured 10 dB bandwidth is about 160 MHz (2.36 -2.52GHz) or 6.6% referred to the centre frequency of 2.44 GHz, which is sufficient to cover 2.4 GHz band. In the 5 GHz band, the measured 10 dB bandwidth is about 3820 MHz (4.07-7.89 GHz) or about 63.9% referred to the centre frequency of 5.98 GHz, which also meets the bandwidth requirement for 5 GHz band. These results agree well with the simulated results.The measured y-z plane and x-y plane radiation patterns are shown in Figure 3. It is seen that the radiation pattern for E polarization in the y-z plane is almost omni-directional at the frequency of 2.44, 5.2, and 5.8 GHz. In the x-y plane, the radiation patterns for E pola...

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