Metasurfaces have promising potential to revolutionize a variety of photonic and electronic device technologies. However, metasurfaces that can simultaneously and independently control all electromagnetics (EM) waves’ properties, including amplitude, phase, frequency, polarization, and momentum, with high integrability and programmability, are challenging and have not been successfully attempted. Here, we propose and demonstrate a microwave universal metasurface antenna (UMA) capable of dynamically, simultaneously, independently, and precisely manipulating all the constitutive properties of EM waves in a software-defined manner. Our UMA further facilitates the spatial- and time-varying wave properties, leading to more complicated waveform generation, beamforming, and direct information manipulations. In particular, the UMA can directly generate the modulated waveforms carrying digital information that can fundamentally simplify the architecture of information transmitter systems. The proposed UMA with unparalleled EM wave and information manipulation capabilities will spark a surge of applications from next-generation wireless systems, cognitive sensing, and imaging to quantum optics and quantum information science.

In this paper, a novel 3-dimensional (3-D) printed circularly polarized (CP) modified Fresnel lens antenna operating at 300GHz is introduced. By virtue of the superior geometric flexibility of the 3-D printing technique, a modified Fresnel lens consisting of subwavelength discrete dielectric posts in the odd-numbered Fresnel zones is proposed. It is further demonstrated that by integrating dielectric anisotropic metamaterial, the modified Fresnel lens can realize CP radiation fed by a simple linearly polarized (LP) open-ended waveguide (OEWG). The 3-D printing approach is also investigated to push the performance envelops of the 3-D printer for realization of the THz CP lens. The measured results show that the axial ratios (AR) of the fabricated antenna prototype are smaller than 3dB from 265 to 320GHz. Moreover, the modified Fresnel lens has a maximum gain of 27.4dBic, which is 0.9dB lager than that of the conventional Fresnel zone plane antenna (FZPA). These validate the concept, the design, and the fabricated prototype.

A high-gain circularly polarized (CP) lens antenna fed by a standard linearly polarized (LP) pyramidal horn operating at 300GHz is proposed in this paper. The high-gain CP lens consists of discrete variable-height dielectric posts and grating. The height of each dielectric post is tuned to realize the required transmission phase, forming a planar wavefront above the lens aperture. By integrating the bottom dielectric grating with anisotropic characteristic, the dielectric lens can transform the incident LP waves from the feed source into CP radiation waves. 3-D printing technique is utilized to fabricate the THz CP lens for simplifying the fabrication process and reducing the cost. Measured results show that the designed lens can realize right hand circular polarization (RHCP) radiation with a gain of 30.8dBic at 300GHz. The measured 1-dB gain bandwidth and 3-dB axial ratio (AR) bandwidth of the THz CP lens can reach 13.3% and 18.8%, respectively. 3-D printed dielectric CP lens for use at THz frequencies is demonstrated, opening new possibilities for future high-speed wireless communications.

Terahertz (THz) lens constitutes a vital component in the THz system. Metasurfaces-based THz metalenses and classical bulky lenses are severely constrained by chromatic/ spherical aberration and the diffraction limit. Consequently, achromatic super-resolution THz lenses are urgently needed. In this study, through translating the required phase distribution into a refractive index (RI) profile with a specific thickness, an innovative approach to designing THz metalenses is proposed and achieved by dielectric gradient metamaterials. The samples fabricated by 3D printing can realize achromatic super focusing with a numerical aperture (NA) of 0.555 from 0.2 to 0.9 THz. Submillimeter features separated by approximately 0.2 mm can be resolved with high precision, such as glass fabric patterns within FR4 panels and fibrous tissue on leaves, with a field of view (FOV) of 90°. Our approach offers a feasible and cost-effective means to implement THz super-resolution imaging, which holds great potential in non-destructive testing and biomedical imaging.

This paper presents a novel design of filtering reflectarray antenna, an integrated module for the combination of filtering and high-gain radiation performance. The filtering reflectarray consists of two-section metal pixel waveguide elements, which can realize the optimized aperture reflection phase distributions in the operating band f1 ≤f ≤ f2 to yield high-gain radiation. Below the lower cut-off frequency f1, the reflection phase distributions drastically deviate from the required ones. Above the upper cut-off frequency f2, both the amplitude and phase distributions fail to provide strong coherent radiation. In the reflectarray synthesis process, a multi-frequency phase matching method (PMM) is further developed, in which the phase compensation for each pixel is implemented at three simultaneous in-band frequencies. Meanwhile, effects of incident angle for elements are also taken into consideration during the reflectarray synthesis. The design of an 11セ × 11セI filtering reflectarray operating from 55 to 65GHz was conveniently fabricated by 3-dimonsional (3-D) printing technology, followed by metal coating with advantages of rapid prototyping, light weight and low cost. Both simulated and measured results show that the proposed reflectarray can realize high-gain radiation within the desired frequency band, but presents effective suppression of out-of-band signals, demonstrating its filtering capability.

High-gain millimeter-wave antennas based on spoof surface plasmon polaritons (SPPs) are proposed in this paper. Since the dispersion of spoof SPP modes supported by metallic grooves is insensitive to their lateral width, we propose two millimeter-wave antennas with wide SPP grooves, namely, an SPP tapering rod antenna and an SPP leaky-wave antenna. The widened grooves enlarge the aperture size of the antennas, enhancing the antenna gains. Both antennas are fed by a standard waveguide and are fabricated by 3D printing with surface metallization. Based on the similar principle of conventional dielectric rod antennas, the proposed SPP rod antenna achieves broadband and high gain. The measured |S11| is below -16.5 dB from 50 to 75 GHz, and the antenna gain varies from 16.06 to 19.3 dBi. By employing periodic modulation, the SPP leaky-wave antenna operates from 50 to 70 GHz for |S11| below -10 dB. This leaky-wave antenna with 24 modulated periods achieves 20.1 to 23.9 dBi gain in the operating band with a beam scanning range from -39° to -3°.