Coupling In Linear Arrays Research Articles

Power Pattern Sensitivity to Calibration Errors and Mutual Coupling in Linear Arrays through Circular Interval Arithmetics.

The sensitivity to both calibration errors and mutual coupling effects of the power pattern radiated by a linear array is addressed. Starting from the knowledge of the nominal excitations of the array elements and the maximum uncertainty on their amplitudes, the bounds of the pattern deviations from the ideal one are analytically derived by exploiting the Circular Interval Analysis (CIA). A set of representative numerical results is reported and discussed to assess the effectiveness and the reliability of the proposed approach also in comparison with state-of-the-art methods and full-wave simulations.

An Open-Source Code for the Calculation of the Effects of Mutual Coupling in Arrays of Wires and for the ASM-MBF Method

A general description of mutual coupling in finite and infinite antenna arrays is provided and an open-source code is described for the analysis of mutual coupling in linear arrays of parallel dipoles. The ASM-MBF method is illustrated with the help of that code and it is shown that the method also can handle situations where eigenmodes are supported by the array: single machine precision is achieved with four Macro Basis Functions only.

Wave propagation and coupling in linear arrays with application to the analysis of large arrays

Waves inside linear arrays are analyzed for the case of single-port excitation. A frequency-domain method is proposed for the extraction of the amplitude decay and phase velocity of the waves, based on simulation results obtained for terminal excitation at one end and near the middle of the array. The waves reflected by the array ends are also extracted, under a single-reflection assumption. This model is then exploited for estimating the port currents when other elements of the array are excited, as well as for larger arrays. Simulation results are shown for port currents and element patterns in arrays of broad-plate dipoles.

Controlling Plasmon Line Shapes through Diffractive Coupling in Linear Arrays of Cylindrical Nanoparticles Fabricated by Electron Beam Lithography

The effect of diffractive coupling on the collective plasmon line shape of linear arrays of Ag nanoparticles fabricated by electron beam lithography has been investigated using Rayleigh scattering spectroscopy. The array spectra exhibit an intricate multi-peak structure, including a narrow mode that gains strength for interparticle distances that are close to the single particle resonance wavelength. A version of the discrete dipole approximation method provides an excellent qualitative description of the observed behavior.

Electronic coupling in linear arrays of quantum cavities characterized using conductance fluctuations

Quantum fluctuations in the conductance produced by the variation of the Fermi energy or a magnetic field are analyzed to investigate the electronic coupling in linear arrays of quantum cavities. The magnetic-field-induced fluctuations exhibit a behavior which implies an incomplete coupling among the quantum cavities. This forms striking contrast to the nearly complete coupling indicated by the energy-induced fluctuations. We examine the dependencies of these coupling coefficients estimated from the conductance fluctuations on various structural parameters. The contradiction between the two coupling coefficients is attributed to the existence of a large number of silent orbits which do not interact with the magnetic field. We also explore the consequences of the series addition of the cavities that are manifested in the underlying classical dynamics.

Mutual coupling compensation in small planar array antennas

Far-field pattern synthesis of small antenna arrays is a nontrivial problem. Typically radiation patterns are required to exhibit low sidelobe levels, whilst maintaining the ability to scan the main beam in space. Mutual coupling is a pertinent problem when the number of antenna elements is small, often precluding the use of conventional tapering algorithms. In this paper a technique previously employed to compensate for mutual coupling in linear arrays is extended to include small planar antenna arrays. The method consists of the calculation of the coupling coefficients between the array elements, which are then formed into a matrix and used to compensate for the effects of mutual coupling. It is then shown that this method is not suitable for all planar array configurations and a new technique is developed which allows the calculation of coupling matrices for these element configurations. Measured data from a small planar antenna array is presented, with the outlined methods employed to produce low sidelobe sum and difference beams.