Web page of project TEC2004-03214

 

PROJECT TEC2004-03214

  1. Some essential data.
  2. Introduction to the project and main goals.
  3. Results.
  4. Associated Ph.D. Thesis.

1.- Some essential data.

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2.- Introduction to the project and main goals.

The analysis and design of microwave circuits realized with planar technology (hybrid and monolithic microwave integrated circuits, (M)MIC) has been a very active research area since the concept of integrated circuit moves to high frequency signal processing at the middle of the sixties. The Microwaves Group at the University of Seville (Seville, Spain), also called GMUS using Spanish initials, has been contributing to this research field - from the point of view of Applied Electromagnetics - during the last 20 years. This project intends to continue the most "classical" lines of research of the group. In the project we deal with a variety of topics sharing analytical/numerical methodology, the nature of the involved electromagnetic systems and the lab facilities required to perform experimental measurements. We have grouped the topics of interest into three big blocks:

Block I: Continuous spectrum of dielectric waveguides and planar transmission lines.

During the last few years a lot of research (mainly of theoretical nature) has been conducted on te topic of the study of the continuous spectrum (related with radiation) of planar printed lines. [Oli84, Oli87, Shi91, Ngh93, Mesa95b, Das96, Lin97, Marques97, DiNallo98, Carin99, Mesa99, Oli00]. This study distinguishes between two kind of contributions to radiation coming from guided systems: leaky wave radiation and residual wave radiation [Jackson00, Mesa01, Mesa02a]. Generally speaking, residual radiation is related with direct radiation of the source to the environment, although due to the translational symmetry of the printed line, this radiation exhibits a longitudinal propagation factor. Leaky wave radiation can be viewed as travelling waves (such as bound modes of the ideal line) which transversally lose energy while propagate. In this research some members of the GMUS have intensely collaborated with the Applied Electromagnetism Group (University of Houston, TX, USA) to develop and apply methods to obtain, in a quasi-analytical way, currents and fields excited by lumped voltage sources - such as delta-gaps or dipoles - along infinite printed lines [Langston01, Mesa02b, Bernal04]. The excitation of the continuous spectrum often gives place to spurious effects which can meaningfully degrade the performance of the printed line as transmission system [Freire99, Mesa02b] or to cause undesired couplings with neighbor lines [Bernal03]. In spite of big advances in this field since the seminal works by Arthur Oliner [Oli87], there are still many theoretical and practical aspects requiring a detailed study for full understanding or predictive value. Among these, we can mention circuital modeling to make easy the manipulation of the phenomenon by the circuit designer or the study of time domain response of such systems. Part of the effort we are developing in this project intends to solve these problems.

We are also interested on the analysis of leaky waves supported by planar multilayered dielectric waveguides (which may include ferrite or (bi)anisotropic materials). These waveguides are the typical guiding systems at optical or quasi-optical frequencies [Tamir90]. Spurious effects associated to the unavoidable excitation of the continuous spectrum can also appear in this type of waveguides. In spite of the continuous effort to characterize leaky waves on dielectric waveguides [Lee95, Mesa95a, Ane99, Petra02], we still face important numerical problems when the dispersion relation of the structure has to be solved [Rod04]. Indeed, we have to find out where are the complex zeros of a complex function having poles and branch points. This mathematical task has been attacked by the GMUS in several occasions (see, for instance [Mesa95a, Rod04]) but we want now to develop a definitive tool able to deal with virtually any kind of layered planar structure (open/closed, (bi)anisotropic, lossy, ...).

References for Block I:

[Ane99] E. Anemogiannis, E. N. Glytsis, and T. K. Gaylord, "Determination of Guided and Leaky Modes in Lossless and Lossy Planar Multilayer Optical Waveguides: Reflection Pole Method and Wavevector Density Method," Journal of Lightwave Technology, vol. 17, pp. 929-941, May 1999.

[Bernal04] J. Bernal, F. Mesa, and D. R. Jackson, "Crosstalk between two microstrip lines excited by a gap voltage source," IEEE Transactions on Microwave Theory and Techniques, vol. 52, n. 8, pp. 1770-1780, August 2004.

[Das96] N. K. Das, "Methods of suppression or avoidance of parallel-plate power leakage from conductor backed transmission lines," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-44, pp. 169-181, February 1996.

[Carin98] L. Carin, G. W. Slade, and K. J. Webb, "Mode coupling and leakage effects in finite-size printed interconnects," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-46, pp. 450-457, May 1998.

[DiNallo98] C. Di Nallo, F. Mesa, and D. R. Jackson, "Excitation of leaky modes on multilayer stripline structures," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-46, pp. 1062-1071, August 1998.

[Freire99] M. J. Freire, F. Mesa, C. DiNallo, D. R. Jackson, and A. A. Oliner, "Spurious transmission effects due to the excitation of the bound mode and the continuous spectrum on stripline with an air gap," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-47, pp. 2493-2502, December 1999.

[Jackson00] D. R. Jackson, F. Mesa, M. J. Freire, D. P. Nyquist, and C. DiNallo, "An excitation theory for bound modes, leaky modes, and residual-wave currents on stripline structures," Radio Science, vol. 35, pp. 495-510, March 2000.

[Langston01] W. Langston, J. T. Williams, D. R. Jackson, and F. Mesa, "Spurious radiation from a practical source on a covered microstrip line," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-49, pp. 2216-2226, December 2001.

[Lee95] S.-L. Lee, Y. Chung, L. A. Coldren, and N. Degli, "On leaky mode approximation for modal expansion in multiplayer open waveguides," IEEE Journal of Quantum Electronics, vol. 31, pp. 1790-1802, October 1995.

[Lin97] Y. Lin and J. Shen, "Mode distinction and radiation efficiency analysis of planar leaky wave line source," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-45, pp. 1672-1680, October 1997.

[Marques97] R. Marqués and F. Mesa, "Spectral domain analysis of higher order leaky modes in microstrip lines: a new spectral-gap effect," Journal of Electromagnetic Waves and Applications, vol. 11, pp. 1367-1384, October 1997.

[Mesa95a] F. Mesa and M. Horno, "Computation of proper and improper in multilayered bianisotropic waveguides," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-43, pp. 233-235, January 1995.

[Mesa95b] F. Mesa and R. Marqués, "Integral representation of spatial Green's function and spectral domain analysis of leaky covered strip-like lines," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-43, pp. 828-837, April 1995.

[Mesa99] F. Mesa, C. DiNallo, and D. R. Jackson, "The theory of surface-wave and space-wave leaky mode excitation on microstrip lines," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-47, pp. 207-215, February 1999.

[Mesa01] F. Mesa, D. R. Jackson, and M. J. Freire, "High-frequency leaky mode excitation on microstrip line," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-49, pp. 2206-2215, December 2001.

[Mesa02a] F. Mesa, D. R. Jackson, and M.J. Freire, "Evolution of leaky modes on printed-circuit lines," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-50, pp. 94-104, January 2002.

[Mesa02b] F. Mesa and D. R. Jackson, "The danger of high-frequency spurious effects on wide microstrip line," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-50, pp. 2679-2689, December 2002.

[Ngh93] D. Nghiem, J. T. Williams, D. R. Jackson, and A. A. Oliner, "Proper and improper dominant mode solutions for stripline with an air gap," Radio Science, vol. 28, pp. 1163-1180, December 1993.

[Oli84] A. A. Oliner, "Historical perspectives on microwave field theory," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-32, pp. 1022-1045, September 1984.

[Oli87] A. A. Oliner, "Leakage from higher modes on microstrip line with application to antennas," Radio Science, vol. 22, pp. 907-912, November 1987.

[Petra01] J. Petrá¢cek and K. Singh, "Determination of Leaky Modes in Planar Multilayer Waveguides," IEEE Photonics Technology Letters, vol. 14, pp. 810-812, June 2002.

[Shi91] H. Shigesawa, M. Tsuji, and A. A. Oliner, "Dominant mode power leakage from printed-circuit waveguide," Radio Science, vol. 26, pp. 559-564, March 1991.

[Oli00] F. Mesa, A. A. Oliner, D. R. Jackson, and M.J. Freire, "The influence of the top cover on the leakage from microstrip line," IEEE Transactions on Microwave Theory and Techniques, vol. MTT-48, pp. 2240-2248, December 2000.

[Rod04] R. Rodríguez-Berral, F. Mesa, and F. Medina, "Systematic and efficient root finder for computing the modal spectrum of planar layered waveguides," International Journal of RF and Microwave Computer-Aided Engineering, vol. 14, n. 1, pp. 73-83, January 2004.

[Tamir90] T. Tamir, ed., Guided-Wave Optoelectronics, Springer-Verlag, New York, 2nd ed. 1990.

Block II: Elliptical and rectangular patch antennas on ferrites.

The second topic of interest in the frame of this project is the numerical and experimental study of several types of "microstrip patch antennas". Due to small size, easy of fabrication, low profile and low cost, patch antennas are very appealing for antenna designers, specially for their use in mobile communication systems, among many other applications. Thus, patch antennas have been used in the design of cell phones, mobile terminals for satellite links, car phones, GPS receivers and WLANs. [Jam89, cap. 19; Poz00]. As well, arrays of such antennas have been used in the fabrication of plane and ship radars, cellular base stations and direct TV broadcast receivers (instead of parabolic antennas) [Jam89, cap.19]. Moreover, these arrays will likely be used in the new wide band wireless netwprks for data transmission both in base stations and user transceivers [Poz00].

In GPS or DBS receivers circular polarization antennas are required [Jam89, cap. 19]. There are two kind of circularly polarized patch antennas: those having single feed and those having with double feed. THose having a single feed point are very simple but the polarization bandwidth uses to be very narrow. Those having too feed points have a much better bandwidth for the axial ratio but the require a rather complex feed circuit [Poz97], and this can be an important problem if those antennas are part of large arrays. In the frame of our project we want to study two types of single feed circularly polarized patch antennas: elliptically shaped patch antennas on dielectric substrate [Lon81,Jun02] and square patch antennas printed on normally biased layered ferrite substrates [Poz92, Tsa98, Leo05a]. In the case of elliptical shaped patches, our purpose is to develop an accurate and efficient algorithm for the rigurous full-wave analysis of such antennas with coaxial probe feed. This algorithm will probably be based on the method of moments formulated in the spectral domain. In order to get high numerical efficiency, current density basis functions should incorporate edge condition, apart from an "attachment mode" [Pin89, Jun02] to ensure probe-patch current continuity and to account for the quasi-singular behavior of patch current density around the point of contact of the coaxial probe [Pin89]. In the past, members of the GMUS have been successful when analyzing resonances of microstrip circular patches [Los99], the scattering of plane waves by circular patches [Los01], and the electrostatic analysis of elliptical patches [Boi90]. Note that, while low eccentricity elliptical patches are expected to be useful radiating circular polarized waves, it has been verified that high eccentricity patches radiate two orthogonal linear waves at two different frequencies [Lon81]. Taking this into account, we want to study the behavior of elliptical antennas as dual band/dual polarization radiators. Theoretical and numerical predictions are expected to be confirmed by the experimental results obtained in our anechoic chamber.

Square patch antennas on ferrite substrates will be studied from the experimental point of view. Theoretical study of this type of antennas has been already carried out in the frame of a former project (TIC2001-3163). The GMUS has some experience on the fabrication and measurement of circuits printed on ferrites, such as coupled line tunable filters [Leo05]. In the case of antennas, these must be magnetized using permanent magnets placed below the ground plane (we do not want to interfere with the radiating side of the antenna [Tsa98]). It is well known that standard microstrip patch antennas are narrow band devices from the point of view of input impedance [Jam89, cap. 1] and that circularly polarized single feed patch antennas are also narrow band from the point of view of axial ratio. But recently, Waterhouse has shown that a single fed patch antenna printed on a high permittivity substrate with a stacked parasitic patch printed over a low permittivity substrate presents a 20 % bandwidth both for input impedance and axial ratio [Wat99]. Starting from this idea, we hope to improve the bandwidth of circularly polarized antennas using stacked patches and a combination of high permittivity (such as ferrites) and low permittivity substrates.

Concerning the presence of ferrites, it is necessary to state that commercial electromagnetic simulators do not often incorporate this kind of materials. Our group has done many contributions to the numerical simulation of planar transmission lines and planar circuits including ferrite layers (see publications in the group web page). These codes will be used in the design of the above mentioned antennas. Nevertheless, we intend to introduce new improvements in this software because, due to the anisotropic nature of ferrites, still requires a lot of computational effort. A research line that has proven to be useful is the adaptation of the Mixed Potentials Integral Equation (MPIE) method [Rao82, Mich90] (MPIE is the heart of many electromagnetic simulators for planar structures) to the analysis of structures with ferrite layers. The GMUS has already contributed to this topic by obtaining the MPIE Green´s functions in the space domain for ferrite layers [Mesa04]. Including these Green´s functions in a MPIE scheme (previously solving those problems arising from the existence of special singularities) would provide a useful code able to deal with arbitrarily shaped patches (thanks to the use of Rao-Wilton-Glisson basis functions) in a relatively fast way.

References for Block II:

[Boi90] R. R. Boix, M. Horno, "Capacitance computation of elliptic microstrip disks in biaxial anisotropic multilayered substrates", IEEE Transactions on Microwave Theory Techniques, vol. MTT-38, pp. 30-37, January 1990.

[Jam89] J. R. James, P. S. Hall, "Handbook of microstrip antennas", Peter Peregrinus Ltd., London, 1989.

[Jun02] H. Jung, C. Seo, "Analysis of elliptical microstrip patch antenna considering attachment mode", IEEE Transactions on Antennas and Propagation, vol. AP-50, pp. 888-890, June 2002.

[Leo05] G. León, R.R. Boix, M.J. Freire, F. Medina, "Experimental Validation of Analysis Software for Tunable Microstrip Filters on Magnetized Ferrites," IEEE Transactions on Microwave Theory and Techniques, vol. 53, n. 5, pp. 1739-1744, May 2005.

G. León, R. R. Boix, M. J. Freire, F. Medina, "Experimental Validation of Analysis Software for Tunable Microstrip Filters on Magnetized Ferrites," IEEE Transactions on Microwave Theory and Techniques, vol. 53, n. 5, pp. 1739-1744, May 2005.

[Lon81] S. A. Long, L. C. Shen, D. H. Schaubert, F. G. Farrar, "An experimental study of the circular-polarized elliptical printed-circuit antenna", IEEE Transactions on Antennas and Propagation vol. AP-29, pp. 95-99, January 1981.

[Los99] V. Losada, R. R. Boix, M. Horno, "Resonant modes of circular microstrip patches in multilayered substrates", IEEE Transactions on Microwave Theory Techniques, vol. 47, pp. 488-498, April 1999.

[Los01] V. Losada, R. R. Boix, F. Medina, "Evaluation of the radar cross section of circular microstrip patches on anisotropic and chiral substrates", IEEE Transactions on Antennas and Propagation vol. AP-49, pp. 1603-1605, November 2001.

[Mesa04] F. Mesa and F. Medina, "Numerical computation of the Mixed Potential space-domain Green's functions for planar layered structures with arbitrarily magnetized ferrites," IEEE Transactions on Antennas and Propagation, vol. 52, n. 11, pp. 3019-3025, November 2004.

[Mich90] K. A. Michalski and D. Zheng, "Electromagnetic scattering and radiation by surfaces of arbitrary shape in layered media, Par I: Theory," IEEE Transactions on Antennas Propagation, vol. AP-38, pp.335-344, Mar. 1990.

[Pin89] S. Pinhas, S. Shtrikman, D. Treves, "Moment-method solution of the center-fed microstrip disk antenna invoking feed and edge singularities", IEEE Transactions on Antennas and Propagation, vol. AP-37, pp. 1516-1522, December 1989.

[Poz92] D.M. Pozar, "Radiation and scattering characteristics of microstrip antennas on normally biased ferrite substrates", IEEE Transactions on Antennas and Propagation, vol. AP-40, pp. 1084-1092, September 1992.

[Poz97] D.M. Pozar, S. M. Duffy, "A dual-band circularly polarized aperture-coupled stacked microstrip antenna for global positioning satellite", IEEE Transactions on Antennas and Propagation, vol. AP-45, pp. 1618-1625, November 1997.

[Poz00] D.M. Pozar, "An overview of wireless systems and antennas", IEEE AP-S International Symposium, Salt Lake City (UT, USA), pp. 566-569, July 2000.

[Rao82] S. M. Rao, D. R. Wilton, and A. W. Glisson, "Electromagnetic scattering by surfaces of arbitrary shape," IEEE Transactions on Antennas Propagation, vol. AP-30, pp. 409-418, May 1982.

[Tsa98] K. K. Tsang, R. J. Langley, "Design of circular patch antennas on ferrite substrates", IEE Proceedings., Pt. H, Microwaves, Opticas and Antennas, vol. 145, no. 1, pp. 49-55, February 1998.

[Wat99] R. B. Waterhouse, "Stacked patches using high and low dielectric constant material combinations", IEEE Transactions on Antennas and Propagation vol. AP-40, pp. 1767-1771, December 1999.

Block III: Periodic structures and filters.

The third central topic of this project is electromagnetic periodic structures. Our purpose is to study two kind of periodic structures: frequency selective surfaces (FSS)and periodic planar transmission lines. Frequency selective surfaces consist of 2D periodic arrays of metallic patches (which act as stop band filters for impinging planar electromagnetic waves) or 2D periodic arrays of slots practiced on a metallic plane (bandpass filters). FSS are used as selective radomes, dichroic subreflectors for parabollic antennas with several feeders operating in several frequency bands or as polarizers [Mun00]. On the other hand, periodic planar lines show two interesting features that make them very useful. First, they are slow wave structures potentially allowing significant reduction of the size of circuits built using these lines as building blocks [Yan98,Sor01]. Second, periodic transmission lines exhibit stop and pass bands that make them useful for filter design [Rad98, Kim00, Sor01]. In the last few years a lot of attention has been paid to two types of planar periodic lines. The first type is made of a conventional microstrip line with a periodically perforated ground plane [Rad98, Kim00] (they have been also called 1D "photonic" or "electromagnetic band gap" structures). The second kind of periodic lines is obtained by introducing periodic perturbations along the plane with metallic patterns of a coplanar waveguide [Sor01]. In Spain, the research group of the Public University of Navarra (Prof. Mario Sorolla Ayza) has been very active in the design of microstrip [Las99, Lop02] and CPW [Mar03] filters based on periodic transmission lines. We hope to make contributions in this research line. Concerning 2D periodic structures, our group intends to develop a fast solver for the analysis of multilayer FSSs. By the end of the eighties Chan and Mittra [Cha88] developed a fast algorithm for the analysis of FSSs based on the spectral domain method of moments in conjunction with FFT techniques. Nevertheless, this algorithm was limited to metal patterns in the unit cell that can be fit to a uniform rectangular mesh. Recently our group has developed a faster algorithm working with nonuniform rectangular meshes [Boi03]. This algorithm is based on interpolations of the spectral Green´s function [Boi96] and the use of suitable transformations of double series slowly convergent into exponentially convergent double series. The most serious drawback of the algorithms in [Cha88] and [Boi03] is the use of the formulation in the spectral domain. Working in this domain force us to use rectangular support basis functions which are not amenable yo arbitrary geometry patches. Space domain formulations, in contrast, would allow us to use triangular support basis functions (RWG functions [Rao82]) suitable for arbitrarily shaped patches. However, a fast method to generate the required space domain Green´s functions should be first developed. Unfortunately, space domain Green´s functions for periodic structures are known in the form of slowly convergent double infinite numerical series. Mathematical extrapolation techniques such as Shank´s transformation [Sin90] have been proposed, but our experience tells us that these techniques are not stable when applied to sophisticated alternating series such as those involved in this problem. On the other hand, Spanish researchers Alvarez-Melcón and J.R. Mosig have reported on two strategies to accelerate the summation of these series [Alv00]. Recently it has been also proposed to use the discrete complex images method (DCIM) in conjunction with Ewald´s transformation [Yu00]. This is a fast method, but our previous research [Shu02] and some other reports state that DCIM presents some problems that should be solved before generating results with confidence. We propose to apply fast summation techniques previously developed for the obtaining of method of moments matrix entries [Boi03] to the computation of Green´s functions. Interpolation/extrapolation methods different from DCIM will be also investigated. Once this problem is solved, moment method schemes using RWG basis functions will be applied. The techniques commented in the previous paragraph can be adapted to deal with periodic planar lines. However, we should take into account that whereas 2D periodic structures are considered in the case of FSSs, 1D periodic structures are now of interest. In this case, Green´s functions involve infinite series of infinite integrals. In spite of this subtle difference (which implies some mathematical challenges) we also intend to develop a code to compute the propagation parameters (propagation constant and Bloch impedance) of the periodic lines. The transmission matrix of the unit cell will be also computed. Although some attention was paid to this problem by the end of the eighties [Gla87, Kia89], there is an important lack of information in the recent literature (an important exception is the paper by Zhu [Zhu03] where the periodicity of the problem is not explicitly exploited). This is a very curious fact if we consider the recent explosion of research on periodic structures!. Note that the scattering parameters of a finite section of periodic transmission line can be easily obtained from the transmission matrices of the input and output discontinuities (these can be computed using a commercial simulator) and from the transmission matrix of the unit cell [Ong02]. This procedure allows us to avoid the electromagnetic analysis of the electrically large whole structure. Important savings of CPU time can be then achieved. The last step of this research is obviously the design, fabrication and measurement of planar filters based on periodic structures.

Apart from periodic filters, we plan also to work on other planar filter configurations. This will follow lines of research already started in a previous project. The general idea is to enhance the performance of conventional planar filters by making use of the patterning of the ground side of the substrate. The development of compact resonators for reduced size filter design will be also an objective of our research. Our group has made recent contributions in these areas, such as the improvement of the out-of-band response of coupled line filters [Vel04] or the development of compact filters of small electrical size (a fraction of a wavelength) based on split ring resonators [Mart04] (this work has been carried out in conjunction with the groups of Prof. Mario Sorolla, UPN, and Ferrán Martín, UAB). Our first goal is to explore the improvements that can be introduced in the behavior of various passive planar devices (mainly filters and couplers) taking advantage of the use of metallic "islands" or slots in the ground plane. Some authors use the term "defected ground structures" (DGS) to name this kind of circuits. Our second goal is to invent, design, simulate and measure compact printed resonators following the way of recent works such as [Ban03, Chen03, Hsi03a, Hsi03b, Zhu03]. We will combine home made software with commercial software so as to carry out this task.

References for Block III:

[Alv00] A. Álvarez Melcón, J. R. Mosig, "Two techniques for the efficient numerical calculation of the Green's functions for planar shielded circuits and antennas", IEEE Transactions on Microwave Theory Techniques, vol. 48, pp. 1492-1504, September 2000.

[Ban03] M. G. Banciu, R. Ramer, and A. Ioachim, "Compact Microstrip Resonators for 900 MHz Frequency Band", IEEE Microwave and Wireless Components Letters, vol. 13, n. 5, pp. 175-177, May 2003.

[Boi96] R. R. Boix, N. G. Alexopoulos, M. Horno, "Efficient numerical computation of the spectral transverse dyadic Green's function in stratified anisotropic media," Journal of Electromagnetic Waves and Applications, vol. 10, n. 8, pp. 1047-1083, August 1996.

[Boi03] R. R. Boix, M. J. Freire, F. Medina, "New method for the efficient summation of double infinite series arising from the spectral domain analysis of frequency selective surfaces," IEEE Transactions on Antennas and Propagation, vol. 52, n. 4, pp. 1080-1094, April 2004.

[Cha88] C. H. Chan, "A numerically efficient technique for the method of moments solution of electromagnetic problem associated with planar periodic structures", Microwave and Optical Technology Letters, vol. 1, No. 10, pp. 372--374, December 1988.

[Chen03] C.-C. Chen, Y.-R. Chen, C.-Y. Chang, "Miniaturized Microstrip Cross-Coupled Filters Using Quarter-Wave or Quasi-Quarter-Wave Resonators", IEEE Transactions on Microwave Theory Techniques, vol. 51, n. 1, pp. 120-131, January 2003.

[Gla87] F. J. Glandorf, I. Wolff, "A spectral-domain analysis of periodically nonuniform microstrip lines", IEEE Transactions on Microwave Theory Techniques, vol. MTT-47, pp. 336-343, March 1987.

[Hsi03a] L.-H. Hsieh, K. Chang, "Compact Elliptic-Function Low-Pass Filters Using Microstrip Stepped-Impedance Hairpin Resonators", IEEE Transactions on Microwave Theory Techniques, vol. 51, n. 1, pp. 193-199, January 2003.

[Hsi03b] L.-H. Hsieh, K. Chang, "Compact, Low Insertion-Loss, Sharp-Rejection, and Wide-Band Microstrip Bandpass Filters", IEEE Transactions on Microwave Theory Techniques, vol. 51, n. 4, pp. 1241-1246, April 2003.

[Kia89] J. F. Kiang, S. M. Ali, J. A Kong, "Propagation properties of striplines periodically loaded with crossing strips", IEEE Transactions on Microwave Theory Techniques, vol. MTT-37, pp. 776-786, April 1989.

[Kim00] T. Kim, C. Seo, "A novel photonic bandgap structure for low-pass filter of wide stopband", IEEE Microwave and Guided Wave Letters, vol. 10, No. 1, pp. 13-15, January 2000.

[Las99] M. A. G. Laso, M. J. Erro, D. Benito, M. J. Garde, T. Lopetegui, F. Falcone, M. Sorolla, "Analysis and design of 1-D photonic bandgap microstrip structures using a fiber grating model", Microwave and Optical Technology Letters, 22, No. 4, pp. 223-226, Aug. 1999.

[Lop02] T. Lopetegui, M. A. G. Lasso, M. J. Erro, M. Sorolla, M. Thumm, "Analsyis and design of periodic structures for microstrip lines by using the coupled mode theory", IEEE Mic. Wireless Comp. Letters, vol. 12, No. 11, pp. 441-443, November 2002.

[Mar03] F. Martín, F. Falcone, J. Bonache, T. Lopetegui, M. A. G. Lasso, M. Sorolla, "Dual electromagnetic bandgap CPW structures for filter applications", IEEE Microwave Wireless Components Letters, vol. 13, No. 9, pp. 393-395, September 2003.[

[Mart04] J. Martel, R. Marqués, F. Falcone, J.D. Baena, F. Medina, F. Martín, M. Sorolla "A new LC series element for compact bandpass filter design", IEEE Microwave and Wireless Components Letters, aceptado en November 2003.

[Mun00] B. A. Munk, "Frequency selective surfaces", Wiley Interscience, New York, 2000.

[Ong02] C. Y. Ong, M. Okoniewski, "A simple recursive formula for calculating the S-parameters of finite periodic structures", IEEE Microwave Wireless Components Letters, vol. 12, No. 7, pp. 264-266, July 2002.

[Rad98] V. Radisic, Y. Qian, R. Coccioli, T. Itoh, "Novel 2-D photonic bandgap structure for microstrip lines", IEEE Microwave and Guided Wave Letters, vol. 8, No. 2, pp. 69-71, February 1998.

[Rao82] S. M. Rao, D. R. Wilton, A. W. Glisson, "Electromagnetic scattering by surfaces of arbitrary shape", IEEE Transactions on Antennas and Propagation vol. AP-30, pp. 409-418, March 1982.

[Shu02] N. V. Shuley, R. R. Boix, F. Medina, M. Horno, "On the fast approximation of Green's functions in MPIE formulations for planar layered media", IEEE Transactions on Microwave Theory Techniques, vol. 50, pp. 2185-2192, September 2002.

[Sin90] S. Singh, W. F. Richards, J. Zinecker, D. R. Wilton, "Accelerating the convergence of series representing the free space periodic Green's function", IEEE Transactions on Antennas and Propagation vol. AP-38, pp. 1958-1962, December 1990.

[Sor01] J. Sor, Y. Qian, T. Itoh, "Miniature low-loss CPW periodic structures for filter applications", IEEE Transactions on Microwave Theory Techniques, vol. MTT-49, pp. 236-2341, December 2001.

[Vel04] M.C. Velázquez, J. Martel, F. Medina, "Parallel coupled microstrip filters with ground plane aperture for spurious band suppression", IEEE Transactions on Microwave Theory and Techniques, vol. 52, n. 3, pp. 1082-1086, March 2004.

[Yan98] F. Yang, Y. Qian, R. Coccioli, T. Itoh, "A novel low-loss slow-wave microstrip structure", IEEE Microwave and Guided Wave Letters, vol. 8, No. 11, pp. 372-374, November 1998.

[Yu00] Y. Yu, C. H. Chan, "Efficient hybrid spatial and spectral techniques in analyzing planar periodic structures with nonuniform discretizations", IEEE Transactions on Microwave Theory Techniques, vol. MTT-48, pp. 1623-1627, October 2000.

[Zhu03] L. Zhu, W. Menzel, "Compact Microstrip Bandpass Filter With Two Transmission Zeros Using a Stub-Tapped Half-Wavelength Line Resonator", IEEE Microwave and Wireless Components Letters, vol. 13, n. 1, pp. 16-18, January 2003.

[Zhu03] L. Zhu, "Guided-wave characteristics of periodic coplanar waveguides with inductive loading--unit-length transmission parameters", IEEE Transactions on Microwave Theory Techniques, vol. MTT-51, pp. 2133-2138, October 2003.

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3.- Results.

In this section we will include those book chapters, journal and conference papers reporting original results of the project. Please, note that

  • INTERNATIONAL CONFERENCE PAPERS/ABSTRACTS

    1. [Berral05a] R. Rodríguez-Berral, F. Mesa, and DR. Jackson, "High-Frequency Excitation of a Microstrip Line by a Probe," 2005 International Microwave Symposium, (Long Beach, CA, USA), Junio 2005, CDROM.

    2. [Mesa05a] F. Mesa, F. Medina, "Solution of the EFIE for printed circuits on ferrite substrates," 2005 USNC/URSI National Radio Science Meeting , (Washington DC, USA), July 3-8 2005, CDROM.

    3. [Bernal05a] J. Bernal, F. Mesa, D.R. Jackson, "The Current Spectrum Excited by a Source on a Lossy Printed-Circuit Line," 2005 USNC/URSI National Radio Science Meeting, (Washington DC, USA), July 3-8 2005, CDROM.

    4. [Mesa05c] F. Mesa, R. Rodríguez-Berral, D.R. Jackson, "High-frequency excitation of microstrip lines by gap sources and probes," XXVIII General Assembly of International Union Radio Science (URSI), (New Delhi, India), October 23-29, 2005. CDROM.

    5. [Baccarelli05a] P. Baccarelli, P. Burghignoli, G. Lovat, S. Paulotto, F. Mesa, D.R. Jackson, "Novel modal transition for leaky modes on microstrip lines," XXVIII General Assembly of International Union Radio Science (URSI), (New Delhi, India), October 23-29, 2005. CDROM.

    6. [Mesa06b] F. Mesa, F. Medina, "Mixed potential integral equation for planar structures with ferrite layers," 11th International Conference on Mathematical Methods in Electromagnetic Theory (MMET'06), (Kharviv, Ukraine), June 26-29, 2006, pp. 83-88 (doi: 10.1109/MMET.2006.1689712) (invited paper, plenary session).

    7. [Mesa06a] F. Mesa, R. Rodríguez-Berral, "Solving the EFIE for a vertical probe exciting an infinite microstrip line," 11th International Conference on Mathematical Methods in Electromagnetic Theory (MMET'06), (Kharviv, Ukraine), June 26-29 (2006) pp. 528-530. (doi: 10.1109/MMET.2006.1689844).

    8. [Berral06a] R. Rodriguez-Berral, F. Mesa, D.R. Jackson, "An Efficient Integral-Equation Approach for a Coaxial Probe Feed on an Infinite Microstrip Line," 2006 IEEE/AP-S International Symposium on Antennas and Propagation, (Albuquerque, New Mexico, USA), July 9 - 15, 2006.

    9. [Bernal06a] J. Bernal, F. Mesa, D.R. Jackson, "Effects of Dielectric and Conductor Losses on the Current Spectrum Excited by a Gap Voltage Source on a Printed-Circuit Line," 2006 IEEE MTT-S International Microwave Symposium, (San Francisco, CA, EEUU), pp. 1307-1310, June 11-16, 2006.

    10. [Langston06a] W.L. Langston, J.T Williams, D.R. Jackson, F. Mesa, "Time-domain pulse propagation on a microstrip transmission line excited by a gap voltage source," 2006 IEEE MTT-S International Microwave Symposium, (San Francisco, CA, EEUU), pp. 1311-1314, June 11-16, 2006.

    11. [Velazquez07a] M.C. Velázquez-Ahumada-Ahumada, J. Martel, F. Medina, "Low-Pass elliptic filters using mixed microstrip-CPW technologies," 2007 Progress in Electromagnetic Research Symposium (PIERS 2007), (Beijing, China), 26-30 March, 2007.

    12. [Velazquez07b] M.C. Velázquez-Ahumada-Ahumada, J. Martel, F. Medina, "Microstrip Coupled Line Filters with Spurious Band Suppression," 2007 Progress in Electromagnetic Research Symposium (PIERS 2007), (Beijing, China), 26-30 March, 2007.

    13. [Boix07] R.R. Boix, F. Mesa, F. Medina, "Closed-Form Expressions for Layered Media Green's Functions that are Reliable both in the Near Field and in the Far Field," Progress in Electromagnetic Research Symposium (PIERS 2007), (Beijing, China), March 2007, pp. 70-72.

    14. [Berral07a] R. Rodriguez-Berral, F. Mesa, ] P. Baccarelli, P. Burghignoli, "Application of the array scanning method to 1D-periodic microstrip lines," 2007 Progress in Electromagnetic Research Symposium (PIERS 2007), (Beijing, China), 26-30 March, 2007.

    15. [Berral07b] R. Rodríguez-Berral, F. Mesa, P. Baccarelli, P. Burghignoli, "Fast Numerical Analysis of a 1D Array of Microstrip Patches," 2007 IEEE AP-S International Symposium, (Honolulu, Hawaii, USA), 10-15 June 2007, pp. 1829-1832.

    16. [Berral07c] R. Rodriguez-Berral, G. Valerio, F. Mesa, P. Baccarelli, P. Burghignoli, and A. Galli, "Full-wave analysis of periodic microstrip lines excited by an aperiodic delta-gap source," 2007 IEEE MTT-S International Microwave Symposium, (Honolulu, Hawaii, EEUU), June 3-8, 2007, pp. 1667-1670.

    17. [Mesa07] F. Mesa, F. Medina, "Solving the EFIE for Printed Layered Structures with Ferrite Layers," BILCEM Computational Electromagnetics Workshop (BILCEM 2007), (Esmirna, Turkía), 30-31 August 2007, pp. 65-69.

    18. [Boix08a] R.R. Boix, A.L. Fructos, F. Mesa, and F. Medina, "Revisited Implementation of theSpectral Kummer-Poisson’s Method for the Efficient Computation of 2-D Periodic Green’s Functions in Homogeneous Media," Progress in Electromagnetic Research Symposium (PIERS), (Hangzhou, China), March 24-28 (2008), pp. 566-567 (Abstratcs Book, ISBN: 978-1-934142-03-5; also in \textit{Proceedings of PIERS 2008, ISBN: 978-1-934142-04-2}, pp. 848--850).

    19. [Boix08b] R.R. Boix, F. Mesa, and F. Medina, "Incorporation of the Continuous Spectrum in Closed Form Expressions for Layered Media Green’s Functions," Progress in Electromagnetic Research Symposium (PIERS), (Hangzhou, China), March 24-28 (2008), p. 262 (Abstratcs Book, ISBN: 978-1-934142-03-5); also in \textit{Proceedings of PIERS 2008, ISBN: 978-1-934142-04-2}, pp. 465--469).

    20. [Velazquez08] M.C. Velázquez-Ahumada, J. Martel, and F. Medina, "Use of ground plane windows and floating conductors in microstrip SIR filters," Progress in Electromagnetic Research Symposium (PIERS), (Hangzhou, China), March 24-28 (2008), p. 427.

    21. [Medina08] F. Medina, F. Mesa, and M. Sorolla, "Extraordinary transmission through periodically perforated screens from a circuit theory perspective," (invited) Progress in Electromagnetic Research Symposium (PIERS), (Hangzhou, China), March 24-28 (2008), p. 385 (Abstratcs Book, ISBN: 978-1-934142-03-5).

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  • NATIONAL CONFERENCE PAPERS/ABSTRACTS

    1. [Mesa05b] F. Mesa, F. Medina, "Implementación numérica del MPIE para estructuras planas con láminas de ferrita arbitrariamente magnetizadas," IV Encontro Ibérico de Electromagnetismo Computacional, (Seia, Portugal), September 7-9, 2005, pp. 35-38 (in Spanish).

    2. [Berral05b] R. Rodríguez-Berral, F. Mesa, D.R. Jackson, F. Medina, "Modelo circuital para la excitación de una línea microtira por una fuente de tensión tipo delta-gap," XX Symposium Nacional de URSI, (Gandía, Valencia), 14-16 Septiembre 2005 (in Spanish).

    3. [Berral06b] R. Rodríguez-Berral, F. Mesa, P. Baccarelli, P. Burghignoli, "Análisis de una línea microtira periódica excitada por una fuente aperiódica," XXI Symposium Nacional de URSI, (Oviedo, Asturias), 12-15 Septiembre 2006 (in Spanish).

    4. [Boix06a] R.R. Boix, F. Mesa, F. Medina, "Obtención de expresiones analíticas para funciones de Green en medios multicapa mediante el método de los mínimos cuadrados totales," XXI Symposium Nacional de URSI, (Oviedo, Asturias), 12-15 Septiembre 2006 (in Spanish).

    5. [Velazquez06a] M.C. Velázquez-Ahumada, J. Martel, F. Medina, "Diseño de un filtro elíptico paso de baja en tecnología híbrida microstrip-CPW," XXI Symposium Nacional de URSI, (Oviedo, Asturias), 12-15 Septiembre 2006 (in Spanish).

    6. [Fructos07] Ana López Fructos, R.R. Boix, F. Mesa, F. Medina, "Un nuevo método para el cálculo eficiente de la función de Green 2D en problemas periódicos 1D y 2D," XXII Symposium Nacional de URSI}, (La Laguna, Tenerife), 19-21 Septiembre 2007, p. 82 (in Spanish, link to full paper).

    7. [Bernal07] Joaquín Bernal Méndez, Francisco Mesa Ledesma, David Jackson, "Efecto de las pérdidas sobre las componentes de la corriente en líneas de transmisión impresas," XXII Symposium Nacional de URSI, (La Laguna, Tenerife), 19-21 Septiembre 2007, p. 81 (in Spanish, link to full paper).

    8. [Berral07d] Raúl Rodríguez Berral, Francisco Mesa, David R. Jackson, "Estudio riguroso de la excitación de una línea microtira mediante un cable coaxial," XXII Symposium Nacional de URSI, (La Laguna, Tenerife), 19-21 Septiembre 2007, p. 82 (in Spanish, link to full paper).

    9. [Velazquez07c] María del Castillo Velázquez Ahumada, Jesús Martel Villagrán, Francisco Medina Mena, "Diseño de filtros compactos basados en resonadores acoplados con ventanas en el plano de masa y conductores flotantes," XXII Symposium Nacional de URSI, (La Laguna, Tenerife), 19-21 Septiembre 2007, p. 51. in Spanish, link to full paper).

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  • PATENTS

    • Inventors (signature order): María del Castillo Velázquez Ahumada, Jesús Martel Villagrán, Francisco Medina Mena.
      Title: Filtros RF y microondas paso bajo usando líneas microtira y guías coplanares combinadas (in Spanish) / RF and microwave low pass filters using combined microstrip and CPW structures.
      Reference number: P200700152
      Country of priority: Spain
      Priority date: January 16 2007.
      Owner Institution: Universidad de Sevilla.

    4.- Associated Ph.D. Thesis.

      • Supervisor: Rafael Rodríguez Boix.
      • Ph.D. Student: Germán León Fernández.
      • Title: "Circuitos y antenas en tecnología plana sobre substratos ferrimagnéticos" (in Spanish)/"Planar circuits and antennas on ferrimagnetic substrates".
      • Place: Dpto. Electrónica y Electromagnetismo, Universidad de Sevilla.
      • Date: 11 de febrero de 2005.

      • Supervisor: Francisco Luis Mesa Ledesma.
      • Ph.D. Student: Raúl Rodríguez Berral.
      • Title: "Análisis de la excitación de líneas microtira uniformes y periódicas" (in Spanish)/"Analysis of the excitation of uniform and periodic microstrip lines".
      • Place: Dpto. Electrónica y Electromagnetismo, Universidad de Sevilla.
      • Date: Beginning 2007.

      • Supervisor: Francisco Medina Mena and Jesús Martel Villagrán.
      • Ph.D. Student: María del Castillo Velázquez-Ahumada Ahumada.
      • Title: "Contribución al estudio de filtros de RF y microondas en tecnología plana" (in Spanish)/"Contribution to the study of RF and microwave filters on planar technology".
      • Place: Dpto. Electrónica y Electromagnetismo, Universidad de Sevilla.
      • Date: 2008.

      • Supervisor: Rafael Rodríguez Boix and Francisco Mesa Ledesma.
      • Ph.D. Student: Ana María López Fructos.
      • Title (tentative): "Estructuras periódicas impresas: análisis y aplicaciones" (in Spanish)/"Printed periodic structures: analysis and applications".
      • Place: Dpto. Electrónica y Electromagnetismo, Universidad de Sevilla.
      • Date: just started. 2010?.

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