Wideband Circularly Polarization and High-Gain of a Slot Patch Array Antenna Realized by a Hybrid Metasurface.

In this paper, a patch array antenna with wideband circular polarization and high gain is proposed by utilizing a hybrid metasurface (MS). A corner-cut slotted patch antenna was chosen as the source due to the possible generation of CP mode. The hybrid MS (HMS), consisting of a receiver MS (RMS) arranged in a 2 × 2 array of squared patches and a linear-to-circular polarization conversion (LCPC) MS surrounding it was then utilized as the superstrate driven by the source. The LCPC MS cell is a squared-corner-cut patch with a 45° oblique slot etched, which has the capability for wideband LCPC. The LCPC unit cell possesses wideband PC capabilities, as demonstrated by the surface current analysis and S-parameter simulations conducted using a Floquet-port setup. The LP EM wave radiated by the source antenna was initially received by the RMS, then converted to a CP wave as it passed through the LCPC MS, and ultimately propagated into space. To further enhance the LCPC properties, an improved HMS (IHMS) was then proposed with four cells cut at the corners, based on the original HMS design. To verify this design, both CMA and E-field were utilized to analyze the three MSs, indicating that the IHMS possessed a wideband LCPC capability compared to the other two MSs. The proposed antenna was then arranged in a 2 × 2 array with sequential rotation to further enhance its properties. As demonstrated by the measurements, the array antenna achieved an S11 bandwidth of 60.5%, a 3 dB AR bandwidth of 2.85 GHz, and a peak gain of 15.1 dBic, all while maintaining a low profile of only 0.09λ0.

OAM vortex wave interaction with phase modulated metasurface.

Phase modulated metasurface (PMM) can control the transmission state of electromagnetic (EM) wave through phase modulation scheme on the interface. Orbital angular momentum (OAM) vortex wave is denoted by the helical phase distribution of the wave front. The interaction between OAM vortex wave and PMM is investigated in this paper. The mathematical model is firstly established according to the array theory. Whereafter, two typical PMMs of chessboard metasurface (CBM) and phase gradient metasurface (PGM) are exploited as examples to uncover the scattering characteristics under illumination of OAM vortex wave. For CBM, the phase cancellation scheme is found to be broken when the OAM order l equals to ±2 under both normal incidence and oblique incidence. It reveals that the OAM vortex wave is a promising approach for metasurface stealth target detection. For PGM, the scattered wave still keeps the OAM feature but is deflected to the non-specular direction, which reveals that the generalized Snell's law is also suitable to OAM vortex wave. The discoveries of this paper may find applications in radar detection fields using OAM vortex wave.

Subtyping children with asthma by clustering analysis of mRNA expression data.

Background: Asthma is a heterogeneous disease. There are several phenotypic classifications for childhood asthma. Methods: Unsupervised consensus cluster analysis was used to classify 36 children with persistent asthma from the GSE65204 dataset. The differentially expressed genes (DEGs) between different asthma subtypes were identified, and weighted gene co-expression network analysis (WGCNA) was carried out. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed for DEGs and critical gene modules. Protein-protein interactions (PPI) were constructed to obtain the hub genes. Finally, differences in the immune microenvironment were analyzed between different subtypes. Results: Two subtypes (C1, C2) were identified using unsupervised consensus clustering. The DEGs between different asthma subtypes were mainly enriched in immune regulation and the release of inflammatory mediators. The important modular genes screened by WGCNA were mainly enriched in aspects of inflammatory mediator regulation. PPI analysis found 10 hub genes (DRC1, TTC25, DNALI1, DNAI1, DNAI2, PIH1D3, ARMC4, RSPH1, DNAAF3, and DNAH5), and ROC analysis demonstrated that 10 hub genes had a reliably ability to distinguish C1 from C2. And we observed differences between C1 and C2 in their immune microenvironment. Conclusion: Using the gene expression profiles of children's nasal epithelium, we identified two asthma subtypes that have different gene expression patterns, biological characteristics, and immune microenvironments. This will provide a reference point for future childhood asthma typing and personalized therapy.