Time-of-flight diffraction method (ToFD) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. Although ToFD can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. In this paper, a new ToFD method for evaluating horizontal planar defects is presented. The finite...

this paper presents a low-cost compact planar microstrip-fed monopole antenna and its four-element array design for ultra-wideband (uwb) wireless communication and target detection applications, respectively, operating in the frequency span of 3 ghz to 11 ghz. a prototype was fabricated and then measured based on optimal parameters. the results of reflection coefficient (s11) and radiation patt...

In this paper a novel method for computing the radiation pattern and also the input impedance of a planar rectangular micro-strip antenna array with consideration of mutual coupling and mutual impedance is presented. Each two triangles with a common edge make an Edge element or RWG. Any such edge element is considered as an infinitesimal dipole. The electrical currents over each dipole can be c...

Linear and planar antenna arrays are synthesized to have maximum directivity for a specified sidelobe level. The directivity is maximized subject to a given SLL. The beamwidth and the zeros of array factor are studied as well as the directivity. Maximum directivity-arrays are compared through some examples with super-directive, uniform, Dolph-Chebyshev and Riblet-Chebychev arrays to find a comp...

In this paper, we present a noble pattern synthesis method of linear and planar array antennas, with non-uniform spacing, for simultaneous reduction of their side-lobe level and pattern distortion during beam steering. In the case of linear array, the Gauss-Newton method is applied to adjust the positions of elements, providing an optimal linear array in the sense of side-lobe level and pattern...

This paper presents a low-cost compact planar microstrip-fed monopole antenna and its four-element array design for ultra-wideband (UWB) wireless communication and target detection applications, respectively, operating in the frequency span of 3 GHz to 11 GHz. A prototype was fabricated and then measured based on optimal parameters. The results of reflection coefficient (S11) and radiation patt...

In this paper, a novel transformation connecting an arbitrary Planar Array to a virtual Uniform Linear Array (ULA) with a larger number of sensors is proposed. The array orientation, number of sensors and phase characteristics of the virtual array are a function of the array shape of the planar array. The two parameter manifold (azimuth,elevation) of a planar array of N sensors is a conoid surf...

We consider array geometries whose direction-of-arrival (DOA) estimation performance is isotropic. An isotropic array is one whose Cramér–Rao bound (CRB) on the DOA of a single source is uniform for all angles. For both planar arrays and volume arrays we derive necessary and sufficient conditions on array element locations so that the array is isotropic. We also present several designs of isotr...