A printed compact coplanar waveguide fed triangular slot antenna for ultra wide band (UWB) communication systems is presented. The antenna comprises of a triangular slot loaded ground plane with a T shaped strip radiator to enhance the bandwidth and radiation. This compact antenna has a dimension of 26 mm × 26 mm when printed on a substrate of dielectric constant 4.4 and thickness 1.6 mm. Design equations are implemented and validated for different substrates. The pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity and virtually steady group delay. The simulation and experiment reveal that the proposed antenna exhibits good impedance match, stable radiation patterns and constant gain and group delay over the entire operating band.

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A high-efficiency and high-gain slotline fed directive dipole antenna for UWB communication and imaging application has been developed. The antenna offers a 2:1 VSWR bandwidth of greater than 10 GHz starting from 3.1 GHz. This antenna offers an average gain of 8 dBi in the entire operating band. The simulation and experimental results show that the proposed antenna exhibits high gain and stable directive radiation patterns which are suitable for imaging applications Introduction: One of the main uses of ultra-wideband (UWB) technology other than high data rate communication is in the field of imaging. But it is very difficult to meet the important criteria such as high gain, directive radiation patterns in the entire band, uniform flat group delays of less than 1 ns and compactness, which are necessary for an imaging antenna. A number of UWB antennas that exhibit moderate gain have been presented in the past decades. The microstrip-fed tapered slot antenna presented in [1] offers an average gain of less than 6 dBi and does not possess stable radiation patterns in the entire frequency band. The antipodal tapered slot UWB antenna presented in [2] obtains its wide bandwidth by merging more than six resonances and does not offer directive radiation patterns in lower bands. In [3] the authors presented a tapered slot UWB antenna, which has a complex structure and non-directive radiation patterns. Hoods and Karacolak in [4] presented a Vivaldi antenna, which offers a small gain and the patterns are nonuniform. In [5] the authors presented an exponentially tapered slot UWB antenna, which offers moderate gain with a large size. The dipole antenna presented in [6] offers a gain of less than 5 dBi and posseses non-uniform radiation patterns at different frequencies. In [7] the authors discussed different UWBs, which are suitable for medical applications. However, these antennas occupy a relatively large space.In this Letter, we present a simple compact uniplanar semicircular directive dipole antenna suitable for UWB imaging applications. This antenna offers a bandwidth greater than 10 GHz starting from 3.1 GHz and an average gain of 8 dBi in the entire frequency band. It possesses directive radiation patterns in all frequencies with a crosspolar level better than 215 dB and a front-to-back ratio greater than 15 dB, which is very suitable for imaging applications. The simulation and experimental studies show that the antenna offers good reflection characteristics, high gain and a robust directive radiation pattern in the entire frequency band.

A novel FGCPW-fed flag-shaped UWB monopole antenna ayman s. al-zayed and shameena v.a.A finite-ground coplanar waveguide (FGCPW)-fed compact ultra-wideband flag-shaped monopole antenna is presented. The antenna consists of a FGCPW-fed monopole asymmetrically loaded with a rectangle strip. The antenna has a compact size of 21.85 × 28 × 1.6 mm 3 . Parametric analysis is conducted to understand the effect of various parameters on the antenna performance. Simple design equations are presented to provide reliable initial design of the antenna if a different substrate is to be used. Constant gain and monopole-like radiation patterns are observed along the entire operating range from 3.1 to 12 GHz. Investigation of the time domain characteristics reveals that the proposed antenna exhibits excellent pulse handling capabilities.

A compact coplanar waveguide-fed (CPW) monopole antenna for ultra-wideband wireless communication is presented. The proposed antenna comprises of a CPW-fed beveled rectangular patch with a modified slotted ground. The overall size of the antenna is 30 mm  27 mm  1.6 mm. The lower edge of the band is attained by properly decoupling the resonant frequencies due to the extended ground plane and the beveled rectangular patch of the antenna. The upper edge of the radiating band is enhanced by beveling the ground plane corners near the feed point. Experimental results show that the designed antenna operates in the 2.7-12 GHz band, for S 11 À10 dB with a gain of 2.7-5 dBi. Both the frequency domain and time domain characteristics of the antenna are investigated using antenna transfer function. It is observed that the antenna exhibits identical radiation patterns and reasonable transient characteristics over the entire operating band. V C 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 22:594-602, 2012.