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This letter presents a dual-polarized filtering patch antenna with high gain, low cross-polarization, and without extra filtering circuits. By etching the slots on the patch, a radiation null at the upper band edge is generated, while introducing an extra resonant mode to broaden the impedance bandwidth. In addition, four shorting pins are symmetrically loaded on the patch, which provides a radiation null at the lower band edge and the enhanced gain. Moreover, the cross-polarization level is reduced by adopting the symmetrical structure and a differential feeding scheme. For verification, a filtering antenna operating at 5G n77 band (3.3–4.2 GHz) is designed and fabricated. The measured 10 dB bandwidth is 29.7% (3.15–4.25 GHz) with a peak gain of 9.5 dBi, a cross-polarization level of less than −32 dB and an isolation of higher than 34 dB. The out-of-band suppression levels are more than 34 and 16 dB within the lower stopband (1–2.52 GHz) and the upper stopband (4.6–6.5 GHz), respectively. [ABSTRACT FROM AUTHOR]

Apolygus lucorum is the dominant pathogenic insect attacking Bacillus thuringiensis (Bt) cotton in China. Additionally, 20‐hydroxyecdysone (20E) has important functions in many biological processes, including insect reproduction. Phospholipase C (PLC), which is an essential enzyme for phosphoinositide metabolism, is involved in 20E signal transduction, but its function in 20E‐mediated reproduction in A. lucorum remains unclear. In this study, 20E increased AlPLCγ transcription as well as the abundance and activity of the encoded protein during molting and metamorphosis. The 20E treatment also induced the considerable accumulation of two second messengers, inositol triphosphate and diacylglycerol. The expression levels of genes encoding vitellogenin (AlVg) and soluble trehalase (AlTre‐1) were similar to those of AlPLCγ, and were upregulated in response to 20E. The silencing of AlPLCγ resulted in downregulated expression of AlTre‐1 and AlVg. However, the silencing of AlTre‐1 and AlVg did not affect AlPLCγ expression. Moreover, the silencing of AlVg did not alter AlTre‐1 expression. Furthermore, an examination of the insect specimens indicated that AlPLCγ is required for female adult reproduction, and that downregulated expression of this gene is associated with decreases in fecundity, adult longevity, and egg hatching rate as well as delayed oocyte maturation. We propose that 20E regulates AlTre‐1 expression via AlPLCγ and affects Vg expression as well as ovary development to facilitate the reproductive activities of A. lucorum females. [ABSTRACT FROM AUTHOR]

An efficient method of moments (MoM) solution of the volume-surface integral equation (VSIE) is presented for the analysis of electromagnetic (EM) scattering and radiation of composite objects comprising arbitrarily contacted dielectrics and conductors. In contrast to the conventional Schaubert–Wilton–Glisson (SWG) and Rao–Wilton–Glisson (RWG) basis functions, which were widely used in the MoM solutions of the VSIE, a new hybrid pulse-rooftop basis function is proposed to explicitly enforce the boundary condition of vanishing tangential electric field at the dielectric–conductor interface. As a consequence, the displacement currents in the dielectrics can be efficiently modeled by a reduced number of volume bases on the same set of meshes, particularly when thin dielectric slabs are involved in the composite structures. The numerical results of EM scattering and radiation of several composite objects are shown to illustrate the accuracy and efficiency of the proposed scheme. Since the new hybrid basis function can be easily implemented into the existing fast algorithms, the VSIE solution presented in this paper is promising for EM problems of composite targets with large size. [ABSTRACT FROM PUBLISHER]

Terahertz (THz) power amplification in coplanar waveguide composite right left-handed transmission line (CPW CRLH TL) metamaterials with carbon nanotubes (CNTs) has been investigated. The negative differential resistance (NDR) behavior of the CNTs with appropriate DC voltage bias, which can be characterized as the feature of the Gunn-type oscillator, Esaki-like diode, or field effect transistor (FET), is used to provide the THz loss compensation/gain. From introducing gaps in the central signal line and short-circuited stubs connected between the CPW central signal line and the ground are used to realize the left-handed (LH) series capacitance C and LH shunt inductance L, respectively. The equivalent circuits model approach and effective medium method are employed to study the propagation constant γ = α + jβ of the CNT-based active THz metamaterials, which are validated by three-dimensional (3D) full-wave finite element (FEM) and circuit model co-design. Results indicate not only the negative attenuation constant α (gain) provided by CNTs but also the negative phase constant β (backward wave propagation with anti-parallel phase and group velocities) by artificial TL configuration at THz frequency region. This planar structure could be used to design tunable THz devices with different DC bias voltage and also easily extended to two-dimensional (2D) and 3D active microwave, IR, or optical metamaterials at room temperature. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:815-818, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25870 [ABSTRACT FROM AUTHOR]