Browsing by Author "Maneiro-Catoira, Roberto"

Now showing items 1-20 of 24

    • A TMA-FDA Approach for Two-Beam Steering 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021)
      [Abstract]: Frequency diverse arrays (FDAs) allow the synthesis of dot-shaped radiated patterns in the range-angle space by applying frequency offsets to the antenna elements. Conventional FDAs are usually implemented with ...

    • Analog Beamforming Using Time-Modulated Arrays With Digitally Preprocessed Rectangular Sequences 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018-03)
      [Abstract]: Conventional time-modulated arrays are based on the application of variable-width periodical rectangular pulses (easily implemented with radio frequency switches) to the individual antenna excitations. However, ...

    • Combining Switched TMAs and FDAs to Synthesize Dot-Shaped Beampatterns 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021)
      [Abstract]: The application of frequency offsets to the elements of a conventional phased array with variable phase shifters (VPSs) leads to frequency diverse arrays (FDAs) with the ability to provide range-angle spatial ...

    • Direct Antenna Frequency-Hopped M-FSK Modulation With Time-Modulated Arrays 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2024-02)
      [Abstract]: We present an innovative approach that simultaneously enables direct antenna frequency-hopped M-ary frequency shift keying (DAFH-MFSK) modulation and beamsteering through the use of time-modulated arrays (TMAs). ...

    • Dual-Beam Steerable TMAs Combining AM and PM Switched Time-Modulation 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (MDPI, 2022)
      [Abstract] Wireless sensor networks (WSN) are increasingly requiring directional antennas that not only provide higher capacity, security, transmission range or robustness against interference, but also contribute with ...

    • Dual-Signal Transmission Using RF Precoding and Analog Beamforming With TMAs 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (IEEE, 2018-06)
      [Absctract]: Time-modulated arrays (TMAs) receiving beamforming provide a noteworthy hardware simplicity given the ability of this multi-antenna technique to transform spatial diversity into frequency diversity. However, ...

    • Dual-Signal Transmission Using RF Precoding and Analog Beamforming With TMAs 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018)
      [Abstract]: Time-modulated arrays (TMAs) receiving beamforming provide a noteworthy hardware simplicity given the ability of this multi-antenna technique to transform spatial diversity into frequency diversity. However, ...

    • Enhanced Time-Modulated Arrays for Harmonic Beamforming 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2017)
      [Abstract]: One of the primary features of time-modulated arrays (TMAs) is their ability to adapt their harmonic patterns to exploit the angular diversity of multipath wireless channels. In such a case, the TMA excitations ...

    • Hybrid Precoding With Time-Modulated Arrays for Mmwave MIMO Systems 

      González-Coma, José P.; Maneiro-Catoira, Roberto; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2018)
      [Abstract]: We consider the utilization of time-modulated arrays (TMAs) as a simple and cost-effective approach to hybrid digital–analog precoding in millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems. ...

    • Impact of Time-Modulated Arrays on the BER of Linear Digital Modulations 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Taylor & Francis, 2015-08-21)
      [Abstract] Time modulation provides a simple way to control the power radiation pattern of an antenna array. By appropriately selecting the parameters of a Time-Modulated Array (TMA) it is possible to obtain a reconfigurable ...

    • Multibeam Single-Sideband Time-Modulated Arrays 

      Maneiro-Catoira, Roberto; García-Naya, José A.; Brégains, Julio; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2020)
      [Abstract]: The design of efficient time-modulated arrays (TMAs) for multi-beam steering purposes must be based on both a type of periodical sequences that guarantees an adequate windowing of exploited harmonics, and a ...

    • NLOS Identification and Mitigation Using Low-Cost UWB Devices 

      Barral Vales, Valentín; Escudero, Carlos J.; García-Naya, José A.; Maneiro-Catoira, Roberto (M D P I AG, 2019-08-08)
      [Abstract] Indoor location systems based on ultra-wideband (UWB) technology have become very popular in recent years following the introduction of a number of low-cost devices on the market capable of providing accurate ...

    • Numerical Model of a 28-GHz Frequency Diverse Array Antenna 

      Angoue Avele, Marc Bernice; Brégains, Julio; Maneiro-Catoira, Roberto; García-Naya, José A.; Castedo, Luis (MDPI AG, 2020-08-22)
      [Abstract] In this work we make use of the frequency diverse array (FDA) concept, whose design is based upon a frequency increment across the antenna elements to generate a beam steering that is a function of angle, time ...

    • On the Feasibility of Time-Modulated Arrays for Digital Linear Modulations: a Theoretical Analysis 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2014)
      [Abstract] Wireless communications are widely based on linear digital modulation methods, which introduce the digital baseband information in the amplitude and/or in the phase of a carrier sinusoid. Time-modulated arrays, ...

    • Performance Analysis of Time-Modulated Arrays for the Angle Diversity Reception of Digital Linear Modulated Signals 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis; Rocca, Paolo; Poli, Lorenzo (Institute of Electrical and Electronics Engineers, 2017)
      [Abstract]: Diversity occurs whenever several copies of the same transmitted signal arrive at a receiver. Such a situation allows for improving the performance of a wireless communication system transmitting over a radio ...

    • Reply to “Comments on ‘Combining Switched TMAs and FDAs to Synthesize Dot-Shaped Beampatterns”’ 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2021)
      [Abstract]: It is noted that the main innovation contained lies in the consideration of frequency diverse arrays (FDAs) feeding networks made up of time-modulating switches (hence, the term TMA-FDA) instead of phase shifters. ...

    • Study of the effects produced by time modulation applied to an antenna array in digital transmission systems 

      Maneiro-Catoira, Roberto (2017)
      [Resumo] Os selos de identidade das comunicacións móbiles e sen fíos de hoxe en día son a demanda continua e crecente de mobilidade, capacidade e fiabilidade, xunto cun firme e definitivo compromiso coa sustentabilidade. ...

    • Time Modulated Arrays: from their Origin to Their Utilization in Wireless Communication Systems 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (M D P I AG, 2017-03-14)
      [Abstract] Time-modulated arrays (TMAs) are electromagnetic systems whose radiated power pattern is controlled by the application of variable-width periodical pulses to the individual elements. The nonlinear nature of the ...

    • Time-modulated array beamforming with periodic stair-step pulses 

      Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Elsevier, 2020-01)
      [Abstract]: Time-modulated arrays (TMAs) are able to improve the side-lobe level of the radiation pattern at the fundamental mode but cannot steer the beam at such a mode towards a given direction. Beam-steering is possible ...

    • 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 ...