Physical emission of spatially‐modulated radar

Abstract

Leveraging the recent development of a physical implementation of arbitrary polyphase codes as spectrally wellcontained waveforms, the notion of spatial modulation is developed whereby a time-varying beampattern is incorporated into the physical emission of an individual pulse. This subset of the broad category of MIMO radar is inspired by the operation of fixational eye movement within the human eye to enhance visual acuity and also subsumes the notion of the frequencydiverse array for application to pulsed radar. From this spatial modulation framework, some specific emission examples are evaluated in terms of resolution and sidelobe levels for the delay and angle domains. The impact of spatial modulation upon spectral content is also considered and possible joint delay-angle emission design criteria are suggested. Simulation results of selected target arrangements demonstrate the promise of enhanced discrimination and the basis for the development of future cognitive radar capabilities that may mimic salient aspects of the visual cortex.

An Overview on Time/Frequency Modulated Array Processing

“…To address the current needs, many advanced array design ideas have appeared in the literature. They include time modulated array (TMA) [9], frequency diverse array (FDA) [10], frequency diversity based multiple-input multiple-output (MIMO) [11]- [13], and waveform diversity array (WDA) [14]- [16]. By connecting and disconnecting the elements from the feed network, TMA can create a beampattern with low sidelobes.…”

DM using FDA antenna for secure transmission

“…Note that FDA is different from the frequency scanning radar using the same frequency at any given time [19] and multiple-input-multipleoutput technique [20]. It is also different from traditional frequency diversity techniques used in distributed sensors [21,22]. The FDA can be regarded as a specific transmit beamforming on phasedarray [23].…”