Design and Analysis of Frequency-Selective Surfaces for Ultrawideband Applications

paper no. 17

Oblique Incidence Performance of UWB Frequency Selective Surfaces for Reflector Applications

paper 436.

Enhanced gain UWB slot antenna with multilayer frequency-selective surface reflector

Adequately design Frequency Selective Surfaces (FSSs) allow significant control of the phase of reflection and transmission characteristics over a wide frequency band. This property is used here to develop a multilayer FSS reflector enhancing the gain and radiation properties of antennas for ultra wideband applications. These kinds of reflectors make structures low profile by providing the flexibility in mounting them closer to antenna without disturbing the impedance bandwidth and providing a good gain control in the main beam direction. In order to design a suitable reflector dual layer FSS have been designed and employed with a slot antenna. FSS layer works from 4 GHz to 12 GHz, providing a linear transmission phase in the 133% bandwidth. Performance of the FSS is tested with UWB slot antenna and predicted results show significant gain enhancement while maintain the bandwidth of 140%. © 2011 IEE

A constant gain ultra-wideband antenna with a multi-layer frequency selective surface

An ultra-wideband (UWB) antenna with a novel multi-layer frequency selective surface (FSS) reflector is presented. A significant enhancement in the gain has been achieved in a low profile design while maintaining the excellent impedance bandwidth of the UWB antenna. The average peak gain of the antenna has been increased from 4 dBi to 9.3 dBi as a consequence of the use of the FSS reflector. More importantly the gain variation within the frequency range from 3 GHz to 15 GHz is only +/-0.5 dB. This is a significant improvement from §2 dB gain variation of the UWB slot antenna without the reflector. This optimized FSS re°ector provides the flexibility of mounting a planar antenna close to conducting bodies, including screens and case

1D-Leaky Wave Antenna Employing Parallel-Plate Waveguide Loaded With PRS and HIS

A new type of one-dimensional leaky-wave antenna (LWA) with independent control of the beam-pointing angle and beamwidth is presented. The antenna is based on a simple structure composed of a bulk parallel-plate waveguide (PPW) loaded with two printed circuit boards (PCBs), each one consisting of an array of printed dipoles. One PCB acts as a partially reflective surface (PRS), and the other grounded PCB behaves as a high impedance surface (HIS). It is shown that an independent control of the leaky-mode phase and leakage rate can be achieved by changing the lengths of the PRS and HIS dipoles, thus resulting in a flexible adjustment of the LWA pointing direction and directivity. The leaky-mode dispersion curves are obtained with a simple Transverse Equivalent Network (TEN), and they are validated with three-dimensional full-wave simulations. Experimental results on fabricated prototypes operating at 15 GHz are reported, demonstrating the versatile and independent control of the LWA performance by changing the PRS and HIS parameters.8 page(s

Enhancing Frequency-Scanning Response of Leaky-Wave Antennas Using High-Impedance Surfaces

International audienc

Frequency Steerable Two Dimensional Focusing Using Rectilinear Leaky-Wave Lenses

The concept of frequency steerable two-dimensional electromagnetic focusing by using a tapered leaky-wave line source embedded in a parallel-plate medium is presented. Accurate expressions for analyzing the focusing pattern of a rectilinear leaky-wave lens (LWL) from its constituent leaky-mode tapered propagation constant are described. The influence of the main LWL structural parameters on the synthesis of the focusing pattern is discussed. The ability to generate frequency steerable focusing patterns has been demonstrated by means of an example involving a LWL in hybrid waveguide printed-circuit technology and the results are validated by a commercial full-wave solver. © 2010 IEEE