  The problem of multi-objective design of sparse MIMO arrays for better
multitarget detection capabilities is considered. A novel approach for
efficient utilization of the antenna design resources; namely, the number of
available array elements, and array aperture are studied for the angular
beamforming performance metrics such as, beam width, the peak to sidelobe ratio
(PSLR), and grating lobe limited field of view. The limiting constraints, the
physical size of elements, and mutual coupling are also considered. Thinning of
fully populated uniform MIMO antenna arrays to form effective uniform sparse
arrays (USA), as the term proposed here, are examined as for their capability
of improving usable field of view (uFOV), beamwidth (BW), and peak-to-side
lobe-ratio (PSLR) using fewer physical antenna elements, simultaneously. Sparse
arrays require much less array elements to outperform uniform linear (ULA) and
rectangular arrays (URA) for their beamwidths. Further, a rigorious design
procedure considering the physical size limitations is currently unavailable.
Here, we present a practical design architecture of such a uniform sparse array
under multiple contradicting objectives. Angular resolution performances of the
novel uniform sparse arrays are compared with the standard ULA and URAs. It is
shown that design of an array with small inter-element spacings avoiding any
grating lobes is possible even when the physical size of the elements are very
large. Expanding the available elements to a much larger apertures provides
much better angular resolution. However, it is also shown that these advantages
come with the cost of increased side lobes. Both the simulated and the measured
results demonstrate the superiority of the proposed uniform sparse array design
compared to classical fully populated uniform arrays.
