  A solid-state active beamformer based on the annular-ring diffraction pattern
is proposed for an integrated photonic platform. Such a circularly symmetric
annular-ring aperture achieves radiating element limited FOV. Furthermore, it
is demonstrated that a multi-annular-ring aperture with a fixed linear density
of elements maintains the beam efficiency for larger apertures while reducing
the beamwidth and side-lobe-level (SLL). A 255-element multi-annular-ring OPA
with active beamforming is implemented in a standard photonics process. 510
phase and amplitude modulators enable beamforming and beam steering using this
aperture. A row-column drive methodology reduces the required electrical
drivers by more than a factor of 5.
