An Additively Manufactured Camera-Lens-Inspired 4D/Shape-Reconfigurable Circular Phased Array for Multi-Octave Ultrawideband, Squint-Free, and Pattern-Invariant Beamforming

Fixed-geometry phased arrays inherently suffer from frequency–aperture coupling: as frequency or scan angle changes, the electrical aperture and element spacing vary, leading to scan loss, beamwidth variation, and pattern distortion, and require continuous phase tracking and calibration to mitigate beam squint. Circular phased arrays (CPAs) offer symmetric 360-degree coverage but remain subject to the same limitations when their geometry is fixed. Recent origami-inspired phased arrays have introduced two-degree-of-freedom (mechanical and electrical) reconfigurability, yet existing demonstrations focus on narrowband pattern diversity rather than wideband beam invariance. This paper presents an additively manufactured (inkjet/3D printed), camera-lens-inspired (origami) circular phased array whose continuously mechanically reconfigured radius maintains a constant electrical aperture, enabling multi-octave (fractional bandwidth of 116 %), squint-free, pattern-invariant beamforming with a single fixed phase set. Measurements demonstrate geometry as a powerful additional degree of freedom for wideband phased arrays with greatly reduced calibration requirements.