Diminishing Returns With Increasing Complexity in Reconfigurable Aperture Antennas

Reconfigurable aperture (RECAP) antennas hold the promise of allowing nearly arbitrary antennas to be synthesized dynamically. An important outstanding question regards the level of RECAP complexity required to capture most of the performance gains in terms of the number of reconfigurable elements (REs) per wavelength and the number of reconfiguration bits (RBs) per reconfigurable element. Diminishing improvement of beamforming performance with increasing RECAP complexity is investigated by considering a square parasitic dipole array with 9 × 9 elements with dimensions 1¿ × 1¿ × 0.5¿. For a fixed RECAP complexity of N
_RE
N
_RB
, it is observed that having higher N
_RE
is more beneficial than high N
_RB
for dynamic beam steering, and that approximately eight REs per wavelength are required to reach diminishing performance returns.