Grating Lobe Reduction Research Articles

Metallic photonic band-gap materials (MPBG) as angular selective reflector or radome: Application to antenna grating lobe reduction

This paper presents numerical and experimental results on metallic photonic band-gap materials (mpbg), composed of metallic wires and used as antenna reflector or radome. Attention is focused on mpbg angular response. In fact, with specified angular characteristics, MPBG materials can be interesting in order to reduce antenna grating lobes. One possible grating lobe reduction solution is based on the use of mpbg as angular filter. The radiation characteristics obtained with this solution are then improved by using a mpbg reflector to enhance the gain. Regarded to a classical metallic reflector, 20 dB and 12 dB gain improvement in the theoretical and in the experimental cases are respectively obtained, when the reflector is composed of more than two layers. The scanning performances are also presented. We show that angular filtering characteristics can be improved either by changing the array interface or by changing the mpbg lattice. In order to select the structure with the best angular behavior, an experimental and numerical characterization method is also presented.

Theoretical study of grating lobes reduction using metallic photonic bandgap materials (MPBG)

A linear array of three half-wavelength dipoles above a metallic reflector is analyzed. The results are then compared with those of the same array above a different kind of metallic photonic bandgap materials. The aim is to find a structure which allows the greatest reduction of the grating lobes (GL). This reduction can be obtained either by a destructive interference in the direction of the grating lobes or by using propagation inside the MPBG, propagation of normal incidence only (main lobe), or in the GL directions only. Then, an MPBG is selected and is completely analyzed (plane wave response, the radiation pattern with just one dipole and with the array in different configurations). As one solution is based on the propagation of particular modes inside the MPBG, this solution can be enhanced by the use of an MPBG reflector on the other side. But this solution is not perfect since there are grating lobes in the E-plane due to the way the waves are guided in the MPBG. One last structure is presented in order to suppress this grating. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 32–41, 1998.

Theoretical study of grating lobes reduction using metallic photonic bandgap materials (MPBG)

Theoretical study of grating lobes reduction using metallic photonic bandgap materials (MPBG)

Synthetic aperture sonar in air medium based on a grating lobe reduction technique

Synthetic aperture sonar in air medium based on a grating lobe reduction technique

凸射影原理による疎アレイ音響ホログラフィにおけるグレーティングローブの低減

凸射影原理による疎アレイ音響ホログラフィにおけるグレーティングローブの低減

Sequentially rotated arrays with reduced sidelobe levels

A companion paper by Smith and Hall (see ibid. vol.141, no.4, p.313-320, 1994) has described the effect of sequential rotation on radiation pattern performance of circularly polarised arrays. Distribution errors result in significant grating lobes that limit bandwidth if resonant elements such as microstrip patches are used. This paper describes the performance of new sequential rotation configurations that reduce grating lobes. Two techniques, rotation of subarrays and large spiral subarrays are discussed. Grating lobe reduction of up to 10 dBs is obtained together with reduction of the pattern frequency dependence.

Grating lobe reduction in ultrasonic synthetic focusing

Two novel schemes of data acquisition in synthetic aperture ultrasonic imaging systems using a linear array transducer are presented to solve the troublesome grating lobe problem. Simulation and experimental results show that in both schemes the grating lobes are significantly reduced without appreciable degradation of the main lobe characteristics.

Far-Infrared-Submillimeter Phased Arrays and Applications

The concept of a phased array of far-infrared (FIR) or submilliieter (SMM) waveguide lasers that can be scanned electronically is presented. Grating lobe reduction by computer analysis is shown. Possible applications of SMM arrays are considered.