A Rectangular NotchBand UWB Antenna with Controllable Notched Bandwidth and Centre Frequency This paper presents the design and realization of a compact ultrawideband (UWB) antenna with a rectangular notch wireless area network (WLAN) band that has controllable notched bandwidth and center frequency. The UWB characteristics of the antenna are achieved by truncating the lower ends of the rectangular microstrip patch, and the notch characteristics are obtained by using electromagnetic bandgap (EBG) structures. EBGs consist of two rectangular metallic conductors loaded on the back of the radiator, which is connected to the patch by shorting pins. A rectangular notch at the WLAN band with high selectivity is realized by tuning the individual resonant frequencies of the EBGs and merging them. Furthermore, the results show that the bandwidth and frequency of the rectangular notch band could be controlled according to the ondemand rejection band applications. In the demonstration, the rectangular notch band was shifted to Xband satellite communication by tuning the EBG parameters. The simulated and measured results show that the proposed antenna has an operational bandwidth from 3.1xe2x80x9312.5 GHz for S11 u003c 10 with a rectangular notch band from 5xe2x80x936 GHz, thus rejecting WLAN band signals. The antenna also has additional advantages: the overall size of the compact antenna is 16 xc3x97 25 xc3x97 1.52 mm3 and it has stable gain and radiation patterns.

Design of QuadPort MIMODiversity Antenna with TripleBand Elimination Characteristics for SuperWideband Applications A compact, lowprofile, coplanar waveguide (CPW)fed quadport multipleinputxe2x80x93multipleoutput (MIMO)diversity antenna with triple bandnotched (WiMAX, WLAN, and Xband) characteristics is proposed for superwideband (SWB) applications. The proposed design contains four similar truncatedxe2x80x93semiellipticalxe2x80x93selfcomplementary (TSESC) radiating patches, which are excited through tapered CPW feed lines. A complementary slot matching the radiating patch is introduced in the ground plane of the truncated semielliptical antenna element to obtain SWB. The designed MIMOdiversity antenna displays a bandwidth ratio of 31:1 and impedance bandwidth (S11 xe2x89xa4 xe2x88x92 10 dB) of 1.3xe2x80x9340 GHz. In addition, a complementary splitring resonator (CSRR) is implanted in the resonating patch to eliminate WLAN (5.5 GHz) and Xband (8.5 GHz) signals from SWB. Further, an Lshaped slit is used to remove WiMAX (3.5 GHz) band interferences. The MIMO antenna prototype is fabricated, and a good agreement is achieved between the simulated and experimental outcomes.