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Sparse reconstruction concept has been successfully applied to the synthesis of maximally sparse array due to the sparsity of the antenna location space. These methods generally discretize the continuous array aperture into a number of grid points and convert the synthesis problems into sparse reconstruction problems. While these strategies have shown advantages over conventional ones, their performance...
In this paper, we propose a novel distortion calibration algorithm for uniform circular array (UCA) based on its special structure. A near-field calibration antenna, located in the center of circular array, is used to estimate the gain and phase uncertainties of elements. Besides, a single far-field source is used to estimate the direction-of-arrival (DoA) and mutual coupling matrix (MCM). Finally,...
A new phased array calibration method based on near-field measurement system such as NSI is proposed in this paper. By measuring a single element antenna near-field and array near-field, calibration parameter is extracted from measured data with twice Fourier Transformation and once Inverse Fourier Transformation. Both amplitude and phase calibration is realized by this method in a very short time...
In this paper, one hybridized method, in which the periodic equivalence principle algorithm is combined with the equivalence principle algorithm, is proposed to solve the finite antenna array with large scale. This method based on the domain decomposition method is more efficient than full-wave methods and more accurate than asymptotical methods with periodic Green's function. Moreover, this approach...
In this letter, an updated periodic equivalence principle algorithm is proposed to solve the radiation problem of large-scale antenna array when the antenna elements are placed closely. The equivalence surfaces enclosing the antenna elements are touched with each other, and the elapsed time in the translation procedure of the periodic equivalence principle algorithm will decrease. The efficiency will...
A simple wideband and dual-polarized array is proposed. It is comprised of connected crossed hollow bowtie antennas. The element design can achieve an impedance bandwidth about 57% (from 1.5 to 2.7GHz). The 3dB gain bandwidth of the element is nearly 70% (from 1.35 to 2.75GHz). Dual polarization can be realized with a the good isolation (−25dB) between different polarization ports. A Γ - shape feed...
Most coherent signal subspace methods (CSM) need singular-value decomposition (SVD) to construct the focusing matrix and eigenvalue decomposition (EVD) when getting noise subspaces. Furthermore, most focusing methods mainly work on ideal antenna element whose radiation pattern is omnidirectional and identical. In this paper, a novel DOA finding method for wideband sources on real antenna array named...
A circular polarized Multi-Beam Antenna (MBA) with 3∶1 bandwidth is described. The enhanced Log Periodic Dipole Array (LPDA) feeds are used to enlarge MBA's 27dB coverage region and improve antenna's maximal gain. The Wavelength-Scaled Array (WSA) is applied to restrain gating lobes. Compared with the single LPDA feed, the 27dB coverage region of this antenna is much lager and the maximal gain is...
A Nyquist-rate time-interleaved current-steering digital-to-analog converter (DAC) with dynamic channel matching (DCM) is proposed. Thanks to the proposed Nyquist-rate time-interleaved architecture, the DAC can properly operate at more than 1GS/s for a near-Nyquist output signal. The key limitation of the time-interleaved architecture is the mismatches between channels. The proposed DCM method can...
A new method of character relations auto-extraction from Chinese text set is proposed in this paper. In this method, characters and their relations are extracted from sentences and documents by computing the relative strength and attributive weight of relative properties. Each dispersed relation is organized and represented by the relative coefficient. For the purpose of exhibiting relations visually,...
We propose a new image device called gigavision camera. The main differences between a conventional and a gigavision camera are that the pixels of the gigavision camera are binary and orders of magnitude smaller. A gigavision camera can be built using standard memory chip technology, where each memory bit is designed to be light sensitive. A conventional gray level image can be obtagray level image...
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