Listar GI-GTEC - Artigos por autor "Brégains, Julio"

Mostrando ítems 41-49 de 49

    • Time-Modulated Arrays Controlled With Sinusoidal Pulsewidth Modulation 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020)
      [Abstract]: In this letter, sinusoidal pulsewidth modulation (PWM) is applied to the design of time-modulated arrays (TMAs). The array excitations are modulated using PWM-synthesized sine waveforms. This provides increased ...

    • Time-Modulated Arrays With Haar Wavelets 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020-11)
      [Abstract]. Time-modulated arrays (TMAs) can effectively perform beamsteering over the first positive harmonic pattern by applying progressively delayed versions of stair-step approximations of a sine waveform to the antenna ...

    • Time-Modulated Multibeam Phased Arrays With Periodic Nyquist Pulses 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018-12)
      [Abstract]: We present a single sideband time-modulated multibeam phased array governed by periodic Nyquist pulsed signals. A Nyquist pulse is a physically realizable approach to the ideal sinc function. Hence, its low-pass ...

    • Time-Modulated Phased Array Controlled With Nonideal Bipolar Squared Periodic Sequences 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2019-02)
      [Abstract]: Bipolar (±1) sequences with no zero state suit particularly well for safeguarding the switched feeding network efficiency when applied to time-modulated arrays. During the zero state of a conventional time-modulating ...

    • TMA–FDA Range-Angle Beamforming With Periodic Linear-Phase Time-Modulating Waveforms 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2022)
      [Abstract]: Frequency diverse arrays (FDAs) provide range-angle time-invariant transmit–receive beamforming, although a fine focus of their radiation patterns is costly since high-resolution mixers and phase shifters are ...

    • Variation in Bandwidths Among Solutions to Shaped Beam Synthesis Problems Concerning Linear Arrays of Parallel Dipoles 

      Brégains, Julio; Ares Pena, F. J. (Institute of Electrical and Electronics Engineers, 2005-01)
      The problem of synthesizing a linear array generating a shaped beam pattern with M filled s has 2M alternative solutions. In this study we examined their bandwidths as regards compliance with pattern quality or input ...

    • Variation in The Bandwidths of Pattern-Quality Parameters and Maximum Embedded Impedance among the Solutions to Shaped-Beam Synthesis Problems for Collinear Dipole Arrays 

      Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (Institute of Electrical and Electronics Engineers, 2003)
      [Abstract] We investigated variation in the bandwidths of ripple, sidelobe level, -3 dB beamwidth, and maximum element embedded (active) impedance (|Z/sup e/|/sub max/) among multiple collinear dipole arrays radiating a ...

    • Very Fast Method to Synthesise Conformal Arrays 

      Fondevila, J.; Rodríguez, J. A.; Brégains, Julio; Moreno Piquero, E.; Ares Pena, F. J. (The Institution of Engineering and Technology, 2007-08-02)
      [Abstract] A very fast technique that allows the synthesising of arbitrary footprint patterns by using conformal arrays with many radiating elements is described. This method is based on a combination of Woodward-Lawson ...

    • Visualizing the 3D Polar Power Patterns and Excitations of Planar Arrays with Matlab 

      Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (Institute of Electrical and Electronics Engineers, 2004-04)
      [Abstrac] This paper discusses the use of Matlab to create three-dimensional polar plots of the power patterns of planar arrays together with 3D plots of the amplitudes and phases of their excitations. A few lines of Matlab ...