Terahertz wavefront manipulation is one of the key terahertz technologies. While few of the research works on terahertz wavefront manipulation has broadband and dual-polarized responses. Here a broadband dual-polarized Huygens’ metasurface is proposed to realize high efficient terahertz wave anomalous refraction. By constructing simultaneous electric and magnetic responses in a bi-layer metasurface to produce Huygens’ resonance, broadband and large phase changes for dual-polarized terahertz wave are achieved. A phase change over 300° with transmission magnitude beyond 0.75 is realized between 0.4 THz and 1 THz. An array made of the metasurface with phase gradient is designed to achieve a 14.0° anomalous refraction for two orthogonal linear polarized waves at 0.93 THz. The structure consists of only two metal layers, providing a simple and high-efficiency design scheme for achieving efficient dual-polarized terahertz wavefront manipulation.

In this letter, we have proposed and demonstrated a novel mixer that requires no local oscillator (LO), but mixes the radio frequency (RF) with its Doppler shifted frequencies on a nonlinear reconfigurable composite right/left-handed transmission line, on which a moving reflective surface is controlled by an external digital circuit. An incident RF encounters a frequency shift when reflected from this moving surface and a difference frequency between the incident frequency and Doppler shifted frequency is generated on this nonlinear transmission line. This kind of mixer has the advantage in high frequency and cognitive radio applications since an LO is not required, meanwhile the intermediate frequency is also tunable electronically.

This paper presents an algorithm structure for an active noise control (ANC) system based on an improved equation error (EE) model that employs the offline secondary path modeling method. The noise of a compressor in a gas station is taken as an example to verify the performance of the proposed ANC system. The results show that the proposed ANC system improves the noise reduction performance and convergence speed compared with other typical ANC systems. In particular, it achieves 28 dBA noise attenuation at a frequency of about 250 Hz and a mean square error (MSE) of about −20 dB.

The phase shifts of dynamic terahertz (THz) phase modulators based on transmissive metasurfaces are usually limited to within 180^∘, which is a necessary amount to perform efficient terahertz wavefront modulation. Few works exhibit a phase shift larger than 200^∘ but with a transmittance less than 3% during modulation. To address this challenge, a dynamic terahertz phase modulator using a dislocation-introduced dual-layer Huygens’ metasurface (HM) with embedded vanadium dioxide (VO₂) is proposed. This compact design uniquely combines high transmittance with a large phase shift in broadband. Key achievements include a maximum dynamic phase shift of 281^∘ at 0.64 THz with a transmittance greater than 50% both before and after a current stimulus. An operational bandwidth where the co-polarization phase shift exceeds 180^∘ is 32.3% under normal incidence. And the bandwidth where the phase shift is larger than 180^∘ and transmittance higher than 50% simultaneously achieves 10.4% from 0.64 THz to 0.71 THz. This innovative dual-layer HM approach efficiently balances the performance of dynamic terahertz phase modulators, opening new possibilities for dynamic terahertz wavefront manipulation devices and providing technical support for terahertz spatial light modulators and terahertz holographic projectors.