Field sampling and field reconstruction: a new perspective

We address the problem of extracting the maximum amount of information on an electromagnetic field over a domain D-O from field sample measurements on a domain D-I, 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 D-O as that radiated by the retrieved source. An extensive numerical analysis highlights the performance of the approach

An approach for restoring the coherence between the scanning surfaces in phaseless near-field antenna characterization

We propose an approach for restoring the coherence between the scanningsurfaces in phaselessnear-fieldantennacharacterization. The approach consists of accounting for the misalignments of the second scanningsurface with respect to the first one directly within the radiation operator, restoring the coherence within the phaselesscharacterization algorithm. The restore of the coherence is demanded to a global optimization stage, performed by an efficient and effective Multilevel, Single-Linkage (MLSL) routine. The proposed method does not require any human intervention, nor it does need any additional hardware instrumentation. Numerical and experimental results show the potentialities of the technique

A novel approach to the design of Generalized Plane Wave Synthesizers

We present an approach for the synthesis of array-based generalized plane wave synthesizers (GPWSs) to generate plane waves in the quiet zone (QZ) region of a test-range. The method allows flexibly accounting for disconnected QZ domains and for disconnected panels of radiators. It permits dimensioning, locating and orienting the panels. By optimizing the singular values behavior (SVB), corresponding to a singular value decomposition (SVD) of the relevant linear, parametric radiation operator, it further enables determining the proper locations of radiators and QZ grid points (enforcing the synthesis constraints) to mitigate the problem ill-conditioning of determining the radiators' excitation coefficients. A proper strategy is also employed to control the overall computational burden. The validity and performance of the method are verified following a numerical analysis, by choosing examples aimed at enlightening the key points of the problem

Fast analysis of conformal aperiodic arrays on CPUs and GPUs

An approach for the fast analysis of “irregular”, i.e., of conformal, periodic or aperiodic, 2D arrays, based on the use of the p-series approach and Non-Uniform FFT (NUFFT) routines is proposed to restore the asymptotic growth of the computing time to that of few, standard FFTs. A sub-array partition strategy is also sketched and shown to further unburden the procedure and controlling the accuracy. The approach has been implemented in both, sequential and parallel codes, enabling its execution on CPUs and on cost-effective, massively parallel computing platforms as Graphic Processing Units (GPUs). Its performance in terms of computational efficiency and accuracy has been assessed also against benchmarks provided by algorithms based on fast Matrix-Vector Multiplication routines