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Peiguo Liu

Publications and source records attributed to Peiguo Liu.

4 recordsLinked to original sources

On-chip nanoplasma for adaptive electromagnetic protection

Over the past decade, semiconductor diodes have served as the primary switching elements in adaptive electromagnetic (EM) protection, yet their performance has been compromised by parasitic effects and thermal accumulation, rendering them inadequate against the rapidly evolving landscape of high-power microwave (HPM) threats. Here we show that on-chip nanoplasma switches (NPMS), composed of gallium nitride electrodes on silicon carbide substrates, exhibit superior radio frequency (RF) and thermal characteristics, positioning them as ideal field-driven switches in RF front-end protectors. By integrating NPMS into metasurfaces, antennas and circuit limiters, we achieve an adaptive response that ensures low-loss transmission for normal signals and high shielding against HPMs, while offering extended operating bandwidth and substantially higher tolerance than conventional solid-state devices. This robust, nanoscale structure has significant potential for protecting unmanned aerial vehicles, radars, satellites and other highly integrated platforms requiring strength and stability in EM environments. The findings of this study open up new routes to support EM safety of high-precision detection and imaging for next-generation RF front ends, with straightforward scalability to millimetre-wave and terahertz frequencies.

physics.app-ph

Field-driven nonlinear metasurface: self-adaptive transition between high-selectivity transmission and broadband shielding

The escalating complexity of electromagnetic (EM) environment is posing a significant challenge to the reliability of modern electronic information systems. To address the need for the spatial EM safety of electronic devices, we present a field-driven nonlinear metasurface (NMS) that enables effective protection against out-of-band interference and in-band high-intensity radiation. By constructing a reconfigurable hybrid coupling topology and mapping it to the metasurface geometry, the proposed NMS achieves a self-adaptive transition between its transmission and shielding mode depending on the incident power. The experimental results are in good agreement with theoretical analysis and full-wave simulation. We obtain a highly selective passband with roll-off rate larger than 20.6dB/GHz and a broadband shielding with shielding effectiveness exceeding 23.6dB and 60% bandwidth, demonstrating a significantly enhanced performance relative to the literature. Our findings establish a promising route toward comprehensive EM protection on radio frequency front-end systems.

physics.optics

Metal Mesh-Based Infrared Transparent Electromagnetic Shielding Windows with Balanced Shielding Properties over a Wide Frequency Range

With the increasing complexity of the electromagnetic environment, electromagnetic interference has already been an important problem for optoelectronic systems to be reckoned with. The metal mesh film is a kind of widely used electromagnetic shielding material with both visible and infrared transparency. However, the shielding performance of previously reported mesh materials is frequency dependent. Here, we report an infrared-transparent electromagnetic shielding windows based on metal mesh with irregular patterns. The mesh coatings are prepared on sapphire substrate using ultraviolet photolithography technology, and provide efficient electromagnetic shielding effectiveness of more than 20 dB in the wide frequency range of 1.7~18 GHz while maintaining high infrared optical transparency. In addition, there is no distinct variation in shielding effectiveness between low and high frequency range, exhibiting a balanced shielding characteristic throughout a broad frequency band. This work could be significant in protecting infrared optoelectronic devices from electromagnetic interference.

physics.optics

Shorted Micro-Waveguide Array for High Optical Transparency and Superior Electromagnetic Shielding in Ultra-Wideband Frequency Spectrum

While functional materials with both light transmitting and electromagnetic shielding are highly desirable, only very few of them meet the stringent electromagnetic interference (EMI) shielding criteria for optoelectronic systems. Here, a design strategy of shorted micro-waveguides (SMWs) array to decouple the light transmission and EMI shielding is proposed and experimentally demonstrated. The array of SMWs, consisting of cut-off metallic micro-waveguides and shorting indium tin oxide (ITO) continuous conductive film, exhibits high optical transmittance of 90.4% and superior EMI shielding effectiveness of 62.2 dB on average over ultra-wide frequency spectrum (0.2-1.3 GHz & 1.7-18 GHz). Compared to previously reported works, an improvement of 19 dB in average shielding effectiveness has been achieved under the same level of light transmission, and the shielding frequency spectrum has been significantly expanded. The working principle has been explained in depth and factors influencing the performance have been investigated for design optimization.

physics.optics