2020/06/08 by Nitin Jonathan Myers, Robert W. Heath, Myers, Nitin Jonathan +1 · 2 citations
Engineering · #Antenna Design and Optimization #Antenna Design and Analysis #Microwave Engineering and Waveguides
paper · pdf · doi:10.48550/arxiv.2006.04964
Phased arrays, commonly used in IEEE 802.11ad and 5G radios, are capable of\nfocusing radio frequency signals in a specific direction or a spatial region.\nBeamforming achieves such directional or spatial concentration of signals and\nenables phased array-based radios to achieve high data rates. Designing beams\nfor millimeter wave and terahertz communication using massive phased arrays,\nhowever, is challenging due to hardware constraints and the wide bandwidth in\nthese systems. For example, beams which are optimal at the center frequency may\nperform poor in wideband communication systems where the radio frequencies\ndiffer substantially from the center frequency. The poor performance in such\nsystems is due to differences in the optimal beamformers corresponding to\ndistinct radio frequencies within the wide bandwidth. Such a mismatch leads to\na misfocus effect in near field systems and the beam squint effect in far field\nsystems. In this paper, we investigate the misfocus effect and propose InFocus,\na low complexity technique to construct beams that are well suited for massive\nwideband phased arrays. The beams are constructed using a carefully designed\nfrequency modulated waveform in the spatial dimension. For the special case of\nbeamforming along the boresight of an array, this waveform is analogous to the\nfrequency modulated continuous wave (FMCW) chirp signal in radar. InFocus\nmitigates beam misfocus and beam squint when applied to near field and far\nfield systems. Simulation results indicate that InFocus enables massive\nwideband phased array-based radios to achieve higher data rates than comparable\nbeamforming solutions.\n