Central Force Optimization (CFO) is a new deterministic multi-dimensional search metaheuristic based on the metaphor of gravitational kinematics. It models “probes” that “fly” through the decision space by analogy to masses moving under the influence of gravity. Equations are developed for the probes’ positions and accelerations using the analogy of particle motion in a gravitational field. In the physical universe, objects traveling through threedimensional space become trapped in close orbits around highly gravitating masses, which is analogous to locating the maximum value of an objective function. In the CFO metaphor, “mass” is a userdefined function of the value of the objective function to be maximized. CFO is readily implemented in a compact computer program, and sample pseudocode is presented. As tests of CFO’s effectiveness, an equalizer is designed for the well-known Fano load, and a 32-element linear array is synthesized. CFO results are compared to several other optimization methods.

/pdf/central-force-optimization-a-new-meta-heuristic-with-4iiiu721hd.pdf

Central force optimization: a new meta-heuristic with applications in applied electromagnetics

Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Method and apparatus for coupling an antenna to a device

From the material presented here, it is clear that the theory underlying the SNF approach is complex and involved to implement. However, it is also very elegant and provides one with many measurement options and powerful capabilities. The numerical implementation of the theory can be efficiently deployed through the use of the fast Fourier transform (FFT) enabling transforms of even electrically large antennas to be accomplished in a matter of a few seconds on a modern powerful digital computer. With the advent of commercially available SNF test systems, the user can exploit these techniques, largely unimpeded by the burden of the theory or the implementation thereof. The material presented here highlighted some of the fundamental concepts and limitations the user needs to be aware of in order to use these test systems with confidence.

/pdf/spherical-near-field-antenna-measurements-5bm37osur0.pdf

Spherical near-field antenna measurements

Surface scattering antennas provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the scattering elements are patch elements. In some approaches, the scattering elements are made adjustable by disposing an electrically adjustable material, such as a liquid crystal, in proximity to the scattering elements. Methods and systems provide control and adjustment of surface scattering antennas for various applications.

Surface scattering antenna improvements

A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.

Backhaul link for distributed antenna system

One- or two-dimensional array of electromagnetic scatterers, characterized in that the aforementioned scatterers are arranged aperiodically on a curved line or surface Reflectarray antenna comprising: at least one such array of electromagnetic scatterers and at least one receiving and/or transmitting feed, cooperating with said array to generate an antenna beam Method for designing and manufacturing said array and said antenna

Aperiodic and non-planar array of electromagnetic scatterers, and reflectarray antenna comprising the same

The problem of antenna characterization from phaseless near-field data is addressed by appropriate use of the available information on the Antenna Under Test (AUT) and on the scanning geometry to provide efficient representations for both the unknowns and the data. Such a strategy allows improving the reliability and the accuracy of the proposed characterization algorithm and, at the same time, shortens the overall measurement process. An extensive numerical and experimental analysis, together with a comparison with existing approaches, endorses the algorithm reliability and accuracy and confirms its usefulness for antennas having a general radiating (vector) behavior, i.e., either focusing or non-focusing.

Phaseless Antenna Characterization by Effective Aperture Field and Data Representations

1Dipartimento di Ingegneria Elettronica ed Ingegneria Informatica, Universita di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Italy 2Dipartimento di Ingegneria Biomedica, Elettronica e delle Telecomunicazioni, Universita di Napoli Federico II, Via Claudio 21, 80125 Naples, Italy 3 SATIMO Italian Office, Via Castelli Romani 59, 00040 Pomezia, Italy 4MI Technologies, Suite 100, 1125 Satellite Boulevard, Suwanee, GA 30024-4629, USA 5Nearfield Systems Inc.19730 Magellan Drive, Torrance, CA 90503, USA

/pdf/recent-advances-in-near-field-to-far-field-transformation-32jiejo3s2.pdf

Recent Advances in Near-Field to Far-Field Transformation Techniques

The diagnosis of the faulty elements of a planar array from noisy far-field power pattern data is considered in the case of "on-off" faults. The possible ambiguities of the solutions are considered both in the theoretical and practical sense and are shown to be intrinsically less relevant than in the widely studied continuous case. The probability of the occurrence of the practical ambiguities is inferred from a number of numerical examples and is shown to be negligible in all cases of interest. An effective algorithm is presented here based on an intersection set finding approach and involving the minimization of a suitable objective functional. The global minimization of the functional has been successfully performed by applying a properly modified genetic algorithm. A number of numerical examples shows the effectiveness of the approach whose computational complexity essentially increases linearly with the array size.

Diagnosis of array faults from far-field amplitude-only data

[1] We address the problem of extracting the maximum amount of information on an electromagnetic field over a domain DO from field sample measurements on a domain DI, with a priori information on the source (or scatterer). The problem is faced in two steps. In the first one, the source reconstruction is dealt with by taking into account the available a priori information and the optimal probe positioning is determined as that optimizing the singular value dynamics of the involved linear radiation operator. The second step consists of reconstructing the field on DO as that radiated by the retrieved source. An extensive numerical analysis highlights the performance of the approach.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009RS004298

Amedeo Capozzoli

Papers

Aperiodic and non-planar array of electromagnetic scatterers, and reflectarray antenna comprising the same

Phaseless Antenna Characterization by Effective Aperture Field and Data Representations

Recent Advances in Near-Field to Far-Field Transformation Techniques

Diagnosis of array faults from far-field amplitude-only data

Field sampling and field reconstruction: A new perspective