Physics

Orbital angular momentum of light

Total angular momentum quantum number

Radar imaging

Algorithm

Radar cross-section

Optics

Modulation (music)

Orbital angular momentum multiplexing

Angular momentum

Azimuth

Antenna (radio)

Acoustics

Scattering

Programming language

SIGNAL (programming language)

Computer science

Radar

Phased array

Classical mechanics

Fast Fourier transform

Telecommunications

IEEE Antennas and Wireless Propagation Letters

A novel radar imaging technique based on orbital angular momentum (OAM) modulation is presented. First, the generation of electromagnetic (EM) vortex wave, which carries the OAM, using incrementally phased uniform circular array (UCA) is introduced, and factors that affect the phase-front distribution are analyzed. Subsequently, echo signal models of both multiple-in-multiple-out and multiple-in-single-out modes are established. The target images are obtained using the fast Fourier transform (FFT) and back-projection methods. Simulation results demonstrate that orbital angular momentum has the prospect for acquiring the azimuth information of radar target. The signal of both OAM modulation and frequency modulation can be used to obtain two-dimensional radar target image. The work can benefit the development of novel information-rich radar based on orbital angular momentum, as well as radar target recognition.

Orbital-Angular-Momentum-Based Electromagnetic Vortex Imaging