Xinxi Zeng

Reconfigurable metamaterials have enabled significant progress toward tunable microwave devices, yet existing approaches are often hindered by limited mechanical reconfigurability and susceptibility to electromagnetic interference. Here, we introduce a type of metamaterial robot that harnesses bistable Kresling origami to achieve dynamic electromagnetic control. By integrating pneumatically driven folding architectures with digital light processing–printed SrTiO ₃ high‐permittivity ceramic patches, our design establishes a unified platform where mechanical deformation and microwave resonant behavior can be actively and synergistically regulated. The coupled extension‐twisting motion inherent to the Kresling geometry simultaneously tailors the axial height, in‐plane orientation, local propagation phase, and boundary conditions of the ceramic resonators, thereby modulating the excitation conditions of dielectric resonance responses across distinct frequency bands. Experimentally, transitioning a single origami unit from its folded state to its deployed state increases the number of resolvable reflection peaks from two to three, with a minimum reflectance reaching approximately −35.6 dB. Rotating the SrTiO ₃ patches further shifts the dual‐resonance center frequencies from 3.71–3.87 Hz and 16.72–17.26 GHz to 4.36–4.45 GHz and 16.31–16.72 GHz, respectively. Expanding this concept to a spatially heterogeneous origami array enables coupled control of both resonance peaks, yielding a minimum peak reflectance as low as −54.4 dB and a reflection modulation depth of 51.0 dB at 12 GHz.

HoFeO ₃ rare earth ferrite exhibits distinctive crystallographic properties; however, its regulatory mechanisms and methods within the terahertz band remain complex. This study employed variable-temperature Raman spectroscopy to explore atomic interactions within the crystal structures of HoFeO ₃ across various modes, spanning temperatures from 20 to 300 K. The fabrication of HoFeO ₃ metamaterials was achieved using 3D direct ink writing additive manufacturing technology, accompanied by the design of a three-coordinate spatial intelligent control structure to manipulate terahertz electromagnetic waves. Variable-temperature Raman spectroscopy revealed twelve active peaks, which included the stretching vibrations of Ho and O, the torsion of FeO ₆ , and the stretching vibrations of Fe-O. Notably, these phonons exhibited softening phenomena with increasing temperature. A low transmittance (transmittance <0.1) of terahertz waves at 0.82 THz was attained through the use of 3D-printed double-layer 90° metamaterials. Furthermore, when the double-layer 45° metamaterials were rotated in the E-H plane around the propagation direction as the central axis, the terahertz waves demonstrated a rotational symmetry transmission law at 0.5 THz. This research offers effective materials and construction methods for metamaterials aimed at regulating terahertz electromagnetic waves.

This paper presents a 90–100 GHz wideband digital phase shifter with a fine resolution of 5.625°, implemented in a 0.13 μm SiGe BiCMOS process. A switch-type architecture with six cascaded units, including a novel 180° cell based on a broadband coupler, enables full 0–360° phase coverage while improving phase accuracy, bandwidth, and process robustness. Post-layout simulations demonstrate an insertion loss below 15.5 dB, an RMS phase error under 2.3°, and an RMS amplitude error better than 0.9 dB across the 90–100 GHz band. The total chip area, including test pads, is 0.39 mm², making the design compact and well suited for high-density phased-array applications.