The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Wind-swath SAR can satisfy the requirement in both high spatial resolution and wide-swath coverage in the same time. As a typical application of wind-swath SAR, displaced phase centers (DPC) multiple azimuth beam (MAB) SAR has an inimitable operating process compare with the conventional SAR system. The paper discuss the possibility of jamming DPC MAB SAR by modulated noise jamming, and provide a...
After summarizing the characteristics of pulse noise, a novel de-noising algorithm combined pulse coupled neural network (PCNN) with mathematical morphology was proposed in this paper. Firstly, noisy points were located using the synchronous pulse burst property of PCNN, then, were processed using the morphological open-close filtering. Finally our algorithm was compared with median filtering, morphological...
Antenna selection is used for increasing the channel capacity of multiple-input multiple-output (MIMO) systems, and reducing the systems complexity and RF chains cost. In this paper, we first study the capacities of MIMO systems, having different antenna assignments between the transmitter and receiver, and propose an optimum assignment from the viewpoint of maximizing the channel capacity. Considering...
In this paper some key technologies of a compact Terahertz Source Based on Free Electron Lasers are studied. In order to obtain a compact Terahertz Source, an independent tunable electron gun played a dominant role. The independent tunable electron gun was calculated firstly. The electron gun can create high-brightness and short-pulse beams (less than 2 ps). The energy spread is less than 0.5%, the...
Periodic dielectric structures are widely used in many areas such as optical communication, material science and millimeter waves in terms of periodic or corrugated waveguide, gratings, leaky wave antennas and bandgap materials. Based on the established rigorous theory for two-dimensionally periodical medium, a great amount of numerical results for cylindrical dielectric waveguide array (CDWA), which...
Based on the established rigorous theory for two-dimensionally periodic (2DP) medium, a great amount of numerical results for Dielectric Waveguide Array (DWA) were presented in this paper. Wave propagation in DWA was analyzed in detail. The applications about transversal and longitudinal propagation in DWA were discussed.
In this paper some key technologies of a THz source based on free electron lasers are discussed. In order to yield exceptionally high quality THz radiation, electron guns are expected to create high-brightness and short-pulse beams, and the normalized rms beam emittance and longitudinal rms emittance should be low. At the same time, a linear accelerator and an undulator should be designed carefully...
A linear programming problem with fuzzy relational parameters is proposed in this paper. It is an extension of the problem (solving fuzzy relation equations with a linear objective function) proposed by Fang and Li (1999). For characterizing the feasible domain of the new problem, two new concepts, f-vertex and vertex of the problem are introduced. It is proved that the minimum of the new problem...
This paper is intended on the estimation of the hopping frequencies of the differential frequency hopping (DFH) signals in white and colored Gaussian noise, respectively. A method based on the combination of the periodogram and the autoregressive moving average (ARMA) modeling-total least squares (TLS) algorithm, is proposed. The spectrum of the signal is firstly evaluated using the periodogram. The...
A new approach to analysing conductor-dielectric periodic structures is presented. The formulations can take the transverse resonance conditions in both conductor and dielectric segments and the effects of their thickness into account. The measurements of the frequency-scanning characteristics of a leaky-wave antenna are in good agreement with the theory.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.