Compact Circularly Polarized Patch Antenna Using a Composite Right/Left-Handed Transmission Line Unit-Cell

A compact circularly polarized (CP) patch antenna using a composite right/left-handed (CRLH) transmission line (TL) unit-cell is proposed. The CRLH TL unit-cell includes a complementary split ring resonator (CSRR) for shunt inductance and a gap loaded with a circular-shaped slot for series capacitance. The CSRR can decrease the TM10 mode resonance frequency, thus reducing the electrical size of the proposed antenna. In addition, the asymmetry of the CSRR brings about the TM01 mode, which can be combined with the TM10 mode by changing the slot radius. The combination of these two orthogonal modes with 90° phase shift makes the proposed antenna provide a CP property. The experimental results show that the proposed antenna has a wider axial ratio bandwidth and a smaller electrical size than the reported CP antennas. Moreover, the proposed antenna is designed without impedance transformer, 90° phase shift, dual feed and ground via

Octet baryon masses in next-to-next-to-next-to-leading order covariant baryon chiral perturbation theory

We study the ground-state octet baryon masses and sigma terms using the covariant baryon chiral perturbation theory (ChPT) with the extended-on-mass-shell (EOMS) renormalization scheme up to next-to-next-to-next-to-leading order (N$^3$LO). By adjusting the available 19 low-energy constants (LECs), a reasonable fit of the $n_f=2+1$ lattice quantum chromodynamics (LQCD) results from the PACS-CS, LHPC, HSC, QCDSF-UKQCD and NPLQCD collaborations is achieved. Finite-volume corrections to the lattice data are calculated self-consistently. Our study shows that N$^3$LO BChPT describes better the light quark mass evolution of the lattice data than the NNLO BChPT does and the various lattice simulations seem to be consistent with each other. We also predict the pion and strangeness sigma terms of the octet baryons using the LECs determined in the fit of their masses. The predicted pion- and strangeness-nucleon sigma terms are $\sigma_{\pi N}=43(1)(6)$ MeV and $\sigma_{s N}=126(24)(54)$ MeV, respectively.Comment: 28 pages, 6 figures, minor revisions, typos corrected, version to appear in JHE

Extraction of Principle Knowledge from Process Patents for Manufacturing Process Innovation

Process patents contain substantial knowledge of the principles behind manufacturing process problems-solving; however, this knowledge is implicit in lengthy texts and cannot be directly reused in innovation design. To effectively support systematic manufacturing process innovation, this paper presents an approach to extracting principle innovation knowledge from process patents. The proposed approach consists of (1) classifying process patents by taking process method, manufacturing object and manufacturing feature as the references; (2) extracting generalized process contradiction parameters and the principles behind solving such process contradictions based on patent mining and technology abstraction of TRIZ (the theory of inventive problem solving); and (3) constructing a domain process contradiction matrix and mapping the relationship between the matrix and the corresponding process patents. Finally, a case study is presented to illustrate the applicability of the proposed approach

Numerical Study of the Near-Field and Far-Field Properties of Active Open Cylindrical Coated Nanoparticle Antennas

A very electrically small, active open cylindrical coated nanoparticle model is constructed, and its electromagnetic properties are investigated in the visible frequency band. Its optical response under both planewave and electric dipole antenna excitations shows very strong dipole behavior at its lowest resonance frequency. The scattering cross section at that dipole resonance frequency is increased by more than +50 dBsm for the planewave excitation. When the open structure is excited by a small current (I0 = 1 × 10−3 A) driven dipole antenna, the maximum radiated power of the composite nanoantenna can be increased by +83.35 dB over its value obtained when the dipole antenna radiates alone in free space. The behaviors under various locations and orientations of the dipole are explored. Dipole orientations along the cylinder axis and symmetric locations of the dipole produced the largest radiated power enhancements. © 2011, IEEE. All rights reserved

Detailed performance characteristics of vertically polarized, cylindrical, active coated nano-particle antennas

The electromagnetic properties of active cylindrical coated nano-particle antennas are investigated. It is demonstrated that the active cylindrical coated nano-particle, whether illuminated by a plane wave or an electric Hertzian dipole (EHD) (small current) element, acts as a strong dipole radiator at its resonant frequency. It is shown that the plane wave scattering cross section could be increased by about 40 dBsm, and the maximum peak of the power radiated by an EHD element could be increased more than 65 dB in the presence of the active nano-particle over its value when radiating into free space. An array, constructed with four active cylindrical coated nano-particles and excited by an EHD element located at or near its center is also studied. Large directivity values, more than 8 dB, are obtained for particular array configurations and EHD locations. © 2012 by the American Geophysical Union