Wed, 09 Jul 2008 13:31:04 BST CiteULike: dcastros periodic http://www.citeulike.org/user/dcastro/tag/periodic CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2809013 <i>URSI (2005)</i> DIPLEXOR COMPACTO DCS-UMTS BASADO EN ESTRUCTURAS PERIÓDICAS Daniel Segovia Ana Robles URSI (2005) 2008-05-18T13:45:32-00:00 2005 URSI diplexer microstrip periodic umts http://www.citeulike.org/user/dcastro/article/2801461 <i>Antennas and Propagation, IEEE Transactions on, Vol. 51, No. 4. (2003), pp. 756-765.</i><br /><br />We present the analysis and design of a microstrip antenna array with a conical beam. The antenna array employs a periodic structure derived from a microstrip on a perforated ground plane. The microstrip antenna array consists of eight leaky lines evenly distributed around a circle. Each line radiates mainly a pair of forward and backward beams, forming a conical beam. The new leaky line design employs the concept of space-harmonic modulation on the EH/sub 0/ mode launched at the common joint of the antenna array. The scattering and dispersion characteristics of the leaky line are thoroughly investigated. It is theoretically and experimentally validated that the perturbation of the photolithographically etched antisymmetric holes excites the leaky EH/sub 1/ mode. Scattering analyses of the surface currents on the microstrip reveal in detail the physical operation of the leaky line. The dispersion characteristics are, thus, established and shown in a Brillouin diagram, indicating the role of each space harmonic, denoted by its complex propagation constant, /spl gamma//sub m,n//sup /spl plusmn//. Constant /spl gamma//sub m,n//sup /spl plusmn// represents a traveling-wave component of the nth higher-order spatial component in association with the EH/sub m/ mode: the superscript, + (-), signifies a forward (backward) traveling wave. For the particular leaky line design, /spl gamma//sub 0,-1//sup +/ and /spl gamma//sub 1,0//sup +/ space harmonics, both showing odd-symmetric field polarization, and both outside the triangular Brillouin region, form the backward and forward leaky waves, respectively. When the leaky lines are evenly and collinearly tied, an 11.5 GHz radial antenna array prototype is formed, and emits a conical beam, showing a 3 dB beamwidth of 24/spl deg/ at the flare angle of 31/spl deg/. A periodic microstrip radial antenna array with a conical beam Kuo-Cheng Chen Yongxi Qian CKC Tzuang T Itoh doi:10.1109/TAP.2003.811064 Antennas and Propagation, IEEE Transactions on, Vol. 51, No. 4. (2003), pp. 756-765. 2008-05-15T12:14:36-00:00 2003 Antennas and Propagation, IEEE Transactions on 51 4 756 765 antenna array microstrip periodic 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/2776273 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 12. (2001), pp. 2336-2341.</i><br /><br />Several novel periodic structures for coplanar waveguides are presented. The proposed structures exhibit low insertion loss in the passband, simple fabrication, and slow-wave characteristics. These structures are applied to realize miniature low-pass filters one-tenth the size of conventional filters, with spurious-free response and deep attenuation levels using only three cells Miniature low-loss CPW periodic structures for filter applications J Sor Y Qian T Itoh doi:10.1109/22.971618 Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 12. (2001), pp. 2336-2341. 2008-05-09T16:40:15-00:00 2001 Microwave Theory and Techniques, IEEE Transactions on 49 12 2336 2341 filer periodic structure http://www.citeulike.org/user/dcastro/article/1870043 <i>Microwave and Wireless Components Letters, IEEE, Vol. 13, No. 4. (2003), pp. 155-157.</i><br /><br />We present the complete band structure of a negative refractive index metamaterial based on the concept of dual transmission lines. The metamaterial is a two-dimensional (2-D) microstrip periodic structure that has cell dimensions much smaller than the wavelength of operation. It can therefore be considered as an effective medium. First, the dispersion characteristics of the metamaterial are explained by way of a 2-D loaded transmission line representation. Subsequently, full-wave analysis is utilized to reveal additional modes that can be excited in the metamaterial. Dispersion analysis of a microstrip-based negative refractive index periodic structure A Grbic GV Eleftheriades Microwave and Wireless Components Letters, IEEE, Vol. 13, No. 4. (2003), pp. 155-157. 2007-11-05T20:31:12-00:00 2003 Microwave and Wireless Components Letters, IEEE 13 4 155 157 metamaterial microstrip periodic structure