Han Wei Tian

Southeast University (China) | SEU

Integrated control of radiated and reflected electromagnetic (EM) waves is of great importance in information science and engineering, which are mostly achieved by elaborately integrating metasurfaces and antennas. However, most of the radiation‐reflection‐integrated designs remain difficulties to modulate the radiated waves directly without cascad...

Signal conversion plays an important role in many applications such as communication, sensing, and imaging. Realizing signal conversion between optical and microwave frequencies is a crucial step to construct hybrid communication systems that combine both optical and microwave wireless technologies to achieve better features, which are highly desir...

Digital coding metasurfaces are an important research branch of metamaterials and metasurfaces. The digital coding method replaces the equivalent medium theory to characterize metasurfaces, which not only simplifies the design process of metasurfaces but also builds a bridge between digital information and metasurface physics. The development of di...

By modulating physical characteristics (amplitude, phase, polarization, etc.) at the subwavelength scale, metasurfaces have shown prominence in controlling electromagnetic waves. However, metasurfaces with linear phase distributions face difficulties in various wavefront reconstructions intentionally and efficiently, and complex‐amplitude metasurfa...

Metasurfaces exhibit promising capacities in the manipulation of electromagnetic (EM) waves, as to diverse dimensions like amplitude, phase, and polarization; even multiple dimensions can be synchronously modulated. Despite the rapid progress in enriching regulatory capabilities of EM waves, primary feeds are integral items however bringing profile...

Manipulating the phase, polarization, and energy distribution of electromagnetic (EM) waves has facilitated numerous applications. Nowadays, metasurface provides an innovational scenario to carry out more promising and advanced control of EM waves. However, it is a great challenge to manipulate polarization, phase, and energy distribution simultane...

We report an ultrawideband array antenna charactered by coding method. The Vivaldi antenna is chosen as radiating element and the array antenna is fed by a 1 to 8 ultrawideband power divider network. The desired coding states are realized by position reverse of the feeding ports and the power divider network is matched by loading three optimized st...

In this paper, we present an ultra-wideband and high-gain antenna based on three-dimensional (3D) impedance-matching metamaterial (IMM) lens. First, we design a 3D IMM lens which can convert spherical-like waves to plane ones and is nearly perfect impedance-matching with the free space. To realize the 3D lens, we propose and design two kinds of ult...

Metasurfaces, composed of prearranged artificial unit cells possessing different electromagnetic (EM) responses, provide unprecedented abilities to realize versatile wave manipulations. Especially in the terahertz spectrum, metasurfaces attract broad attention by opening up further possibilities for wave regulating. Terahertz applications in variou...

Metasurfaces are engineered surfaces that consist of subwavelength periodic elements and can be used to manipulate electromagnetic waves. Multifunctional or reconfigurable electromagnetic meta-devices based on a direct-current biasing system can be built using lumped electronic components. However, such meta-devices require bulky power supplies, fi...

Chiral molecules that do not superimpose on their mirror images are the foundation of all life forms on earth. Chiral molecules exhibit chiroptical responses, i.e., they have different electromagnetic responses to light of different circular polarizations. However, chiroptical responses in natural materials, such as circular dichroism and optical r...

In article number 1900141, Wei Xiang Jiang, Tie Jun Cui, and co‐workers propose and realize a type of millimeter‐wave (mmW) digital metasurface based on nematic liquid crystals (NLCs). By tuning the bias voltage loaded on the NLCs, different phase responses can be obtained from different metasurface elements and are represented by digital codes. Th...

Metasurfaces provide an unprecedented capability in manipulating electromagnetic waves. In this work, a millimeter‐wave (mmW) digital coding metasurface based on nematic liquid crystals (NLCs) is proposed and realized. By tuning the bias voltage loaded on the NLCs, the effective permittivity of the NLCs substrate is changed, thus providing differen...

We propose a low-profile and high-gain pattern-reconfigurable planar array antenna (PRPAA) based on digital coding characterization. The radiating elements in the PRPAA are designed ingeniously to realize digital "0" and "1" elements. By dynamically encoding the digital radiating elements with different coding patterns, various radiation beams can...

Beam diversity enables antenna arrays to play important roles in radar, communications, imaging, and next-generation wireless systems. However, achieving flexible control of beams in a low-cost way is still very challenging. Here, we propose low-profile planar antenna arrays with coding elements to control and engineer radiation patterns more freel...