Fri, 08 Aug 2008 20:06:49 BST CiteULike: dcastros Mao http://www.citeulike.org/user/dcastro/author/Mao CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2782047 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 4. (2005), pp. 1515-1521.</i><br /><br />The novel one-dimensional left-handed microstrip lines (LHMLs) consisting of the arrays of thin wires and two-layer split-ring resonators are investigated theoretically and experimentally in this paper. Unlike the conventional left-handed metamaterials for waveguides or microstrip lines, which are bulky three-dimensional constructions or require the lumped elements for high-pass configuration, this distributed structure can be directly implemented on a substrate by photolithographic techniques without soldering any chip inductors or capacitors. Moreover, it can also be easily realized at a higher frequency region by scaling the dimensions of the structure, making it highly efficient and flexible in millimeter-wave applications. To characterize the inhomogeneous LHML, the effective medium description is developed for extracting the effective electromagnetic parameters, i.e., the complex effective permittivity and permeability, as well as the refractive index. Results show that not only the simultaneously negative real permittivity and permeability, but also the antiparallel phase and group velocities may be achieved in the design passband region. In contrast to the antenna array using the conventional microstrip delay line, the LHML is incorporated in the series-fed microstrip combline array to exhibit the leading phase between the successive elements. Effective electromagnetic parameters of novel distributed left-handed microstrip lines Shau-Gang Mao Shiou-Li Chen Chen-Wei Huang doi:10.1109/TMTT.2005.845192 Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 4. (2005), pp. 1515-1521. 2008-05-09T23:56:00-00:00 2005 Microwave Theory and Techniques, IEEE Transactions on 53 4 1515 1521 lh line microstrip http://www.citeulike.org/user/dcastro/article/2782046 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 50, No. 11. (2002), pp. 2624-2628.</i><br /><br />Wave propagation along the finite-width conductor-backed coplanar waveguide (FW-CBCPW) with periodically loaded one-dimensional electromagnetic bandgap (EBG) cells proposed earlier by the authors is investigated theoretically and experimentally in this paper. The full-wave simulation in conjunction with Floquet's theorem is employed to find the dispersion diagram for characterizing the guided and leaky waves over a wide frequency range. For examining the guided-wave mode, the equivalent-circuit model is established to obtain the analytical formula of the Bloch impedance. The remarkable slow-wave factor 1.9-2.9 times higher than that of a conventional FW-CBCPW is presented. When operating frequency is sufficiently high, the leaky-wave mode is emitted so that the structure radiates in the backward direction. Good agreement among the results of the full-wave simulation, equivalent-circuit model, published data, and measurement supports the usefulness of the proposed full-wave simulation and also validates the analytical formula. By properly adjusting the circuit configuration, the periodic EBG structure with controllable propagation characteristics, which include the bandgap zone, the slow-wave factor, and the Bloch impedance for the guided wave, as well as the radiation main beam for the leaky wave, may be achieved. Propagation characteristics of finite-width conductor-backed coplanar waveguides with periodic electromagnetic bandgap cells Shau-Gang Mao Ming-Yi Chen doi:10.1109/TMTT.2002.804515 Microwave Theory and Techniques, IEEE Transactions on, Vol. 50, No. 11. (2002), pp. 2624-2628. 2008-05-09T23:55:59-00:00 2002 Microwave Theory and Techniques, IEEE Transactions on 50 11 2624 2628 ebg periodic propagation http://www.citeulike.org/user/dcastro/article/2782045 <i>Microwave and Wireless Components Letters, IEEE, Vol. 11, No. 6. (2001), pp. 261-263.</i><br /><br />The one-dimensional (1-D) periodic electromagnetic bandgap (EBG) structure for the finite-width conductor-backed coplanar waveguide (FW-CBCPW) is proposed. Unlike the conventional EBG structures for the microstrip line and the coplanar waveguide (CPW), which are typically placed on one of the signal strips and the ground plane, this EBG cell is etched on both the signal strip and the upper ground plane of FW-CBCPW resulting in a novel circuit element. The equivalent circuit is also used to model the EBG cell. Measured and full-wave simulated results show that the cell exhibits remarkable stopband effect. The low-pass filter with lower cutoff frequency and wider rejection bandwidth is constructed from a serial connection of the EBG cells. The effect of back metallization on the guiding characteristic is also discussed. Compared to the published EBG cells, the proposed structure has the advantages of relative flexibility, higher compactness, lower radiation loss, and easier integration with the uniplanar circuits A novel periodic electromagnetic bandgap structure for finite-width conductor-backed coplanar waveguides Shau-Gang Mao Ming-Yi Chen doi:10.1109/7260.928932 Microwave and Wireless Components Letters, IEEE, Vol. 11, No. 6. (2001), pp. 261-263. 2008-05-09T23:55:57-00:00 2001 Microwave and Wireless Components Letters, IEEE 11 6 261 263 ebg periodic structure http://www.citeulike.org/user/dcastro/article/1880289 <i>Antennas and Propagation, IEEE Transactions on, Vol. 54, No. 4. (2006), pp. 1084-1091.</i><br /><br />This study investigates in detail the left-handed (LH) properties of the two-layer microstrip line, periodically loaded with broadside-coupled split ring resonators (BC-SRRs) and vias. The mechanism of the left-handed microstrip line (LHML), which includes the diamagnetic response, the backward-wave propagation and the proportionality of the guided wavelength on frequency, is discussed in terms of the field and current distributions and the dispersion diagram. To examine the resonance of the BC-SRR, both the full-wave eigenmode analysis and the closed-form formula based on the quasistatic approach are developed. The effects of the BC-SRR shape on the resonant frequency are evaluated. To facilitate the computer-aided-design (CAD) applications of the LHML, the equivalent-circuit model, which comprises the three-conductor coupled microstrip line for the coupling section, the series LC for the BC-SRR, and the shunt inductance for the via, is established. Good agreement among the results of the full-wave simulation, equivalent-circuit model, published data, and measurement supports the usefulness of the proposed modeling methodology and also validates the analytical expressions. The application of the LHML in the microstrip rectangular loop antenna fed by the conductor-backed coplanar waveguide-to-conductor-backed coplanar stripline (CBCPW-to-CBCPS) transition is presented to highlight the unique features of the LHML. Compared with the conventional loop antenna, the LHML-loaded loop antenna achieves a 50% area reduction and the 52% of main beam steering. Characterization and modeling of left-handed microstrip lines with application to loop antennas Shau-Gang Mao Shiou-Li Chen Antennas and Propagation, IEEE Transactions on, Vol. 54, No. 4. (2006), pp. 1084-1091. 2007-11-07T18:39:29-00:00 2006 Antennas and Propagation, IEEE Transactions on 54 4 1084 1091 antenna crlh metamaterial microstrip http://www.citeulike.org/user/dcastro/article/1846444 <i>Computer, Vol. 29, No. 3. (1996), pp. 31-44.</i><br /><br />Artificial neural nets (ANNs) are massively parallel systems with large numbers of interconnected simple processors. The article discusses the motivations behind the development of ANNs and describes the basic biological neuron and the artificial computational model. It outlines network architectures and learning processes, and presents some of the most commonly used ANN models. It concludes with character recognition, a successful ANN application Artificial neural networks: a tutorial AK Jain Jianchang Mao KM Mohiuddin Computer, Vol. 29, No. 3. (1996), pp. 31-44. 2007-10-31T10:27:02-00:00 1996 Computer 29 3 31 44 network neural tutorial