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In this paper, a block of active phased antenna subarray module for the high resolution synthetic aperture radar (SAR) applications was designed, fabricated and measured. The measured results of the module show perfect characteristics and verified by the experiment.
The study of Armstrong codes is motivated by the problem of understanding complexities of dependencies in relational database systems, where attributes have bounded domains. A (q, k, n)-Armstrong code is a q-ary code of length n with minimum Hamming distance n − k + 1, and for any set of k − 1 coordinates there exist two codewords that agree exactly there. Let f(q, k) be the maximum n for which such...
In this paper, we present a wideband distributed bidirectional multiple-input — multiple-output (MIMO) channel sounder. It is developed for characterizing up to 4×4 MIMO channel in four frequency bands from 2GHz to 15GHz with 100MHz bandwidth. To fully understand the dynamic characteristics of multilink MIMO, such as distributed and cooperative MIMO, the radio over fiber (RoF) techniques is adopted...
According to the infrared imaging mechanism, this paper proposes a Nonuniformity Correction(NUC) enhancement method to improving the image quality of Infrared system. analyzing the connection between the responsivety and the nonuniformity of each pixel on infrared focal plane array (IRFPA), gain and offset coefficients were updated gradually, calculating the image of a scene threshold gray level information,...
In order to respond to sudden environmental pollution incidents and reduce their damage and loss, an emergency decision-making system need to be built. The air pollution emergency plan system based on WebGIS, which relies on the on-site monitoring data in real time, simulates the spread and distribution of the on-site pollutants to assist decision-makers to make an appropriate emergency plans. Among...
A dual-polarized phased array antenna for synthetic aperture radar (SAR) application is introduced in this paper. The RF topology configuration is illuminated briefly. An antenna module was tested and the measured results are presented, with which an applied array antenna should be extended with RF distribution networks, power supply and control subsystem used.
A robust source enumeration algorithm is proposed for coherent signals at low signal-to-noise ratio conditions. The approach determines the source number by exploiting the modified covariance matrix and its eigenvectors other than the eigenvalues used in traditional methods. By using a series of transformation of the snapshot vectors and eigenvectors, new decision variables which have better immunity...
A comparison between the National Institute of Metrology (NIM) and the Beijing Institute of Radio Metrology and Measurement (BIRMM) Programmable Josephson Voltage Standards (PJVS) at 1 V level was carried out at Changping campus of NIM from November 16 to November 17, 2009. The measured difference voltage between the two PJVS is 2×10-10 in direct comparison and 4×10-9 in indirect comparison. The results...
This work proposes an antenna design based on a size optimized planar inverted-F antenna (PIFA) with meander structure for multiple-input-multiple-output (MIMO) handset applications. Two elements orientations on half PCB, which cover different translations and rotations, are investigated in terms of diversity performance. A highly efficient parallel dualelement meander PIFA array prototype is implemented...
The grid-connected photovoltaic generation system is the most important one in the field of photovoltaic application. In this paper, a model of photovoltaic has been constructed based on the main circuit of single phase grid-connected generation system using MATLAB/simulink to program it. The double closed loop control structure is adopted and forward-feed compensation method is employed to the system...
Aiming at the combination of BF (Beamforming) and MIMO (Multiple Input and Multiple Output), a generalized wireless downlink transmission scheme with the named of BF-MIMO is presented. According to a series of transformations of the signals in the transmit and receive antenna pairs, a combined flat fading channel matrix is analyzed and formulated. And then, based on the steering vector of transmit...
Photovoltaic generation system is made an overall and systematic introduction from several aspects. In this paper, the attention is devoted to research the maximum power point tracking (MPPT) based on analyze the output character of photovoltaic array, and mainly study the CVT method, increase conductance (IncCond) method, variable step MPPT method, and variable step IncCond method based improved...
In this paper, by using the FDTD method combining with the even-odd mode theory, the distribution of the even- and odd-mode voltages on the inner slots corrugated CPW bend and the bend with hole array are obtained. The simulated results show that for the even-mode voltage, the wave velocity is slowed down in the corrugation slot, but is speeded up in the slot with hole array. For the odd-mode voltage,...
To investigate the effects of phosphene array irregularity in visual prostheses, a model of phosphenes' positional uncertainty was devised and two different image down-sampling schemes, adapting and non-adapting, were proposed. Based on a simulation system, visual acuity tests were given to four normally sighted subjects under seven degrees of array irregularity and the two down-sampling schemes....
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