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.