  Conventional sensing applications rely on electromagnetic far-field channel
models with plane wave propagation. However, recent ultra-short-range
automotive radar applications at upper millimeter-wave or low terahertz (THz)
frequencies envisage operation in the near-field region, where the wavefront is
spherical. Unlike far-field, the near-field beampattern is dependent on both
range and angle, thus requiring a different approach to waveform design. For
the first time in the literature, we adopt the beampattern matching approach to
design unimodular waveforms for THz automotive radars with low weighted
integrated sidelobe levels (WISL). We formulate this problem as a unimodular
bi-quadratic matrix program, and solve its constituent quadratic sub-problems
using our cyclic power method-like iterations (CyPMLI) algorithm. Numerical
experiments demonstrate that the CyPMLI approach yields the required
beampattern with low autocorrelation levels.
