Properties of Multiple Microstrip Properties of Multiple Microstrip Antennas in Several Layers of Antennas in Several Layers of

Anisotropic MaterialAnisotropic Material

A Dissertation ProposalA Dissertation Proposal

By Benjamin BraatenBy Benjamin Braaten

February 19, 2008February 19, 2008

OutlineOutline►BackgroundBackground

The microstrip antenna and mutual couplingThe microstrip antenna and mutual coupling Previous workPrevious work

►Proposed researchProposed research Research questionsResearch questions Technical objectives and work planTechnical objectives and work plan Initial workInitial work

►Significance of anticipated resultsSignificance of anticipated results►ConclusionConclusion

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BackgroundBackground► Since Deschamps's [1] formal presentation of a Since Deschamps's [1] formal presentation of a

microstrip antenna in 1953 and detailed discussion by microstrip antenna in 1953 and detailed discussion by AlexopoulosAlexopoulos

[2] there has been an extensive amount of research[2] there has been an extensive amount of research devoted to the study of various printed antennas and devoted to the study of various printed antennas and

arrays. arrays. ► It is well known that printed antennas are [3] It is well known that printed antennas are [3]

very lightvery light occupy a small volumeoccupy a small volume are useful at higher frequencies (f>1GHz)are useful at higher frequencies (f>1GHz) provide a wide range of patternsprovide a wide range of patterns

[1] G.A. Deschamps, “Microstrip Microwave Antennas,” 3rd USAF Symposium on Antennas, 1953.[2] N.G. Alexopoulus, “Integrated-circuit structures on anisotropic substrates,” IEEE Transactions on Microwave Theory and Techniques, Vol. 33, No. 10, October 1985, pp. 847-881.[3] David M. Pozar and Daniel H. Schaubert, “Microstrip Antennas: The analysis and Design of Microstrip Antennas and Arrays,” IEEE Press, Piscataway, NJ, 1995.

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BackgroundBackground

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BackgroundBackground► Region between

plates act like the region between a transmission line and a ground plane with both ends open.

► Results in standing wave.

► Fringing fields are responsible for radiation.

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BackgroundBackground►Properties of interest includeProperties of interest include

Input impedanceInput impedance Current distributionCurrent distribution Radiation patternsRadiation patterns Band-widthBand-width Feed techniques Feed techniques Mutual impedance with other elementsMutual impedance with other elements Conducting patch layout … etc.Conducting patch layout … etc.

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Previous work-isolated Previous work-isolated antennasantennas

► In 1979 a significant step In 1979 a significant step was taken by Uzunoglu, was taken by Uzunoglu, Alexopoulos and Fikioris [9]Alexopoulos and Fikioris [9] microstrip dipolesmicrostrip dipoles radiation propoertiesradiation propoerties Based on Green’s function Based on Green’s function

for a hertizian dipole over for a hertizian dipole over a grounded isotropic a grounded isotropic substratesubstrate

► Working from that base, Working from that base, Rana and Alexopoulos Rana and Alexopoulos presented work in 1981 on presented work in 1981 on the current distribution and the current distribution and input impedance of printed input impedance of printed dipoles [10].dipoles [10].

[9] N.K. Uzunoglu, N.G. Alexopoulos and J.G. Fikioris, “Radiation properties of microstrip dipoles,'‘ IEEE Transactions on Antennas and Propagation, Vol. 27, No. 6, November 1979, pp. 853-858.[10] I.E. Rana and N.G. Alexopoulos, “Current distribution and input impedance of printed dipoles,” IEEE Transactions on Antennas and Propagation, Vol. 29, No. 1, January 1981, pp. 99-105. 7/25

Previous work-isolated Previous work-isolated antennasantennas

► The above work with Green's functions in the spectral form The above work with Green's functions in the spectral form laid the foundation for future work by Pozar [11] and others to laid the foundation for future work by Pozar [11] and others to analyze properties of other various microstrip antennas.analyze properties of other various microstrip antennas.

► In parallel with the development by Alexopoulos and his In parallel with the development by Alexopoulos and his colleagues, in 1980 and 1981, Itoh and Mentzel [12]-[13] colleagues, in 1980 and 1981, Itoh and Mentzel [12]-[13] developed a spectral domain immittance approach.developed a spectral domain immittance approach.

► This lead to the work by Lee and Tripathi [15] and later This lead to the work by Lee and Tripathi [15] and later Nelson, Rogers and d’Assuncao [16] to study layered Nelson, Rogers and d’Assuncao [16] to study layered anisotropic structures.anisotropic structures.[11] D.M. Pozar, “Input impedance and mutual coupling of rectangular microstrip antennas,”

IEEE Transactions on Antennas and Propagation, Vol. 30, No. 6, November 1982, pp. 1191-1196.[12] T. Itoh, “Spectral domain immitance approach for dispersion characteristics of generalized printed transmission lines,” IEEE Transactions on Antennas and Propagation, Vol. 28, No. 7, July 1980, pp. 733-736.[13] T. Itoh and W. Menzel, “A full-wave analysis method for open microstrip structures,” IEEE Transactions on Microwave Theory and Techniques, Vol. 29, No. 1, January 1981, pp. 63-68.[15] H. Lee and V.K. Tripathi, “Spectral domain analysis of frequency dependent propagation characteristics of planar structures on uniaxial medium,” IEEE Transactions on Microwave Theory and Techniques, Vol. 30, No. 8, August 1982, pp. 1188-1193.[16] R.M. Nelson, D.A. Rogers and A.G. D'Assuncao, “Resonant frequency of a rectangular microstrip patch on several uniaxial substrates,” IEEE Transactions on Antennas and Propagation, Vol. 38, No. 7, July 1990, pp. 973-981. 8/25

Previous work-mutual Previous work-mutual couplingcoupling

► In 1981, Alexopoulos and Rana [22] study the In 1981, Alexopoulos and Rana [22] study the mutual impedance between printed dipoles mutual impedance between printed dipoles (Green’s function in spectral form)(Green’s function in spectral form)

► Then in 1982, PozarThen in 1982, Pozar presents the mututalpresents the mututal impedance betweenimpedance between rectangular microstriprectangular microstrip antennas [11]antennas [11]

[22] N.G. Alexopoulos and I.E. Rana, “Mutual impedance computation between printed dipoles,” IEEE Transactions on Antennas and Propagation, Vol. 29, No. 1, January 1981, pp. 106-112.[11] D.M. Pozar, “Input impedance and mutual coupling of rectangular microstrip antennas,” IEEE Transactions on Antennas and Propagation, Vol. 30, No. 6, November 1982, pp. 1191-1196.9/25

Current workCurrent work► In 1998, Waterhouse, Targonski and Kokotoff In 1998, Waterhouse, Targonski and Kokotoff

[36] discuss the design and performance of [36] discuss the design and performance of using shorting posts on a microstrip patch using shorting posts on a microstrip patch antenna on an isotropic substrate.antenna on an isotropic substrate.

► In 2001, Verma and Nisimuddin [34] In 2001, Verma and Nisimuddin [34] investigate the input impedance of rectangular investigate the input impedance of rectangular microstrip antennasmicrostrip antennas Different from work by Oliveira and d’Assuncao [20]Different from work by Oliveira and d’Assuncao [20]

[36] R.B. Waterhouse, S.D. Targonski and D.M. Kokotoff, “Design and performance of small printed antennas,” IEEE Transactions on Antennas and Propagation, Vol. 46, No. 11, November 1998.[20] J.R.S. Oliveira and A.G. D'Assuncao, “Input impedance of microstrip patch antennas on anisotropic dielectric substrates,” Antennas and Propagation Society International Symposium, 1996. AP-S. Digest, Vol. 2, July 21-26, 1996, p. 1066-1069.[34] A.K. Verma and Nasimuddin, “Input impedance of rectangular microstrip patch antenna with iso/anisotropic substrate-superstrate,'‘ IEEE Microwave and Wireless Components Letters, Vol. 11, No. 11, November 2001, pp. 456-458.

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Current workCurrent work► Also in 2001, Also in 2001,

Shackelford, Lee, Shackelford, Lee, Chatterjee, Guo, Luk Chatterjee, Guo, Luk and Chair [39] present a and Chair [39] present a small-sized wide-band small-sized wide-band U-slot and L-probe fed U-slot and L-probe fed microstrip antenna with microstrip antenna with shorting walls.shorting walls.

[34] A. Shackelford, K.F. Lee, D. Chatterjee, Y.X. Guo, K.M. Luk and R. Chair, “Small-size wide-bandwidth microstrip patch antennas,” IEEE Antennas and Propagation Society International Symposium, 2001,Vol. 1, July 8-13, 2001, pp. 86-89.

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Current workCurrent work► In 2003 Yang and Samii [48] presented a low mutual coupling In 2003 Yang and Samii [48] presented a low mutual coupling

design of an array of electromagnetic band gap structures. design of an array of electromagnetic band gap structures. Used FDTDUsed FDTD Single anisotropic substrateSingle anisotropic substrate

► In 2005 Chair, Kishk and Lee [49] presented work on the In 2005 Chair, Kishk and Lee [49] presented work on the mutual coupling between a 2 element array of circular patch mutual coupling between a 2 element array of circular patch antennas.antennas. Used IE3D [44]Used IE3D [44] Single isotropic substrate on an isotropic dielectric substrate. Single isotropic substrate on an isotropic dielectric substrate.

► Then, in 2007, Buell, Mosallaei and Sarabandi [45] used Then, in 2007, Buell, Mosallaei and Sarabandi [45] used metamaterial to suppress the mutual coupling between metamaterial to suppress the mutual coupling between elements in a densely packed array. elements in a densely packed array. metamaterial as isolation walls between the elements.metamaterial as isolation walls between the elements.

[48] F. Yang and Y. Rahmatt-Samii “Microstrip antennas integrated with electromagnetic band-gap (EBG) structures: a low mutual coupling design for array applications,'‘ IEEE Transactions on Antennas and Propagation, Vol. 51, No. 10, October 2003, pp. 2936-2946.[49] R. Chair, A.A. Kishk and K-F. Lee, “Comparative study on the mutual coupling between different sized cylindrical dielectric resonators antennas and circular microstrip patch antennas,” IEEE Transactions on Antennas and Propagation, Vol. 53, No. 3, March 2005, pp. 1011-1019.[44] www.zeland.com.[45] K. Buell, H. Mosallaei and K. Sarabandi, “Metamaterial insulator enabled superdirective array,” IEEE Transactions on Antennas and Propagation, Vol. 55, No. 4, April 2007, 1074-1085. 12/25

Proposed researchProposed researchConsider the following Consider the following

structure:structure:

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Proposed researchProposed researchRESEARCH QUESTIONS:RESEARCH QUESTIONS:

► What is the input impedance of a driven element in What is the input impedance of a driven element in the layered anisotropic structure in the presence of the layered anisotropic structure in the presence of other conducting patches defined on arbitrary other conducting patches defined on arbitrary anisotropic layers in the same structure?anisotropic layers in the same structure?

andand

► What is the mutual impedance between a driven What is the mutual impedance between a driven element in the layered anisotropic structure and element in the layered anisotropic structure and other conducting patches defined on arbitrary other conducting patches defined on arbitrary anisotropic layers in the same structure?anisotropic layers in the same structure?

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Proposed researchProposed researchThe previous two questions are very The previous two questions are very

significant in many fields. significant in many fields. Microstrip antenna arrays [3].Microstrip antenna arrays [3]. Frequency Selective Structures (FSS) [53]Frequency Selective Structures (FSS) [53] Radio Frequency Identification (RFID) [56]Radio Frequency Identification (RFID) [56]

[3] David M. Pozar and Daniel H. Schaubert, “Microstrip Antennas: The analysis and Design of Microstrip Antennas and Arrays”, IEEE Press, Piscataway, NJ, 1995.[53] A.L.P.S. Campos an A.G. d'Assuncao, “Scattering paramters of a frequnecy selective surface between anisotropic dielectric layers for incidnet co-polarized plane waves,” IEEE Antennas and Propagation Society International Symposium, 2001, Vol. 4, July 8-13, 2001, p. 382-385.[56] K. Finkenzeller, RFID Handbook:Fundamentals and Applications in Contactless Smart Cards and Identification, John Wiley and Sons, West Sussex, England, 2003.

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Technical ObjectivesTechnical Objectives► Choose the appropriate types of microstrip Choose the appropriate types of microstrip

antennas that will allow the work to proceed to antennas that will allow the work to proceed to answer the proposed questions.answer the proposed questions.

► Choose and develop the numerical technique Choose and develop the numerical technique that can be used to compute the input that can be used to compute the input impedance and mutual coupling between impedance and mutual coupling between elements in the anisotropic structure.elements in the anisotropic structure.

► Validate numerical results for the isotropic case Validate numerical results for the isotropic case with commercially available software.with commercially available software.

►Design and build a multiple layered structure to Design and build a multiple layered structure to measure and validate the numerical measure and validate the numerical calculations of input impedance and mutual calculations of input impedance and mutual coupling.coupling.

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Work PlanWork Plan► Choose the appropriate types of microstrip Choose the appropriate types of microstrip

antennas that will allow the work to proceed antennas that will allow the work to proceed to answer the proposed questions.to answer the proposed questions. Printed dipoles by Alexopoulos and Rana [10]Printed dipoles by Alexopoulos and Rana [10] Rectangular microstrip antennas by Nelson [16], Rectangular microstrip antennas by Nelson [16],

Pozar [19], and Oliveira [20].Pozar [19], and Oliveira [20]. UWBUWB

[10] I.E. Rana and N.G. Alexopoulos, “Current distribution and input impedance of printed dipoles,” IEEE Transactions on Antennas and Propagation, Vol. 29, No. 1, January 1981, pp. 99-105.[16] R.M. Nelson, D.A. Rogers and A.G. D'Assuncao, “Resonant frequency of a rectangular microstrip patch on several uniaxial substrates,” IEEE Transactions on Antennas and Propagation, Vol. 38, No. 7, July 1990, pp. 973-981.[19] D.M. Pozar, “Radiation and scattering from a microstrip patch on a uniaxial substrate,” IEEE Transactions on Antennas and Propagation, Vol. 35, No. 6, June 1987, pp. 613-621.[20] J.R.S. Oliveira and A.G. D'Assuncao, “Input impedance of microstrip patch antennas on anisotropic dielectric substrates,” Antennas and Propagation Society International Symposium, 1996. AP-S. Digest, Vol. 2, July 21-26, 1996, p. 1066-1069. 17/25

Work PlanWork Plan► Choose and develop the numerical technique that can be Choose and develop the numerical technique that can be

used to compute the input impedance and mutual coupling used to compute the input impedance and mutual coupling between elements in the anisotropic structure.between elements in the anisotropic structure. Exact Green’s function [11, Pozar]Exact Green’s function [11, Pozar]

► Numerical integration and derivatives are extensiveNumerical integration and derivatives are extensive► Developed to evaluate problems with anisotropic materialDeveloped to evaluate problems with anisotropic material► Developed to evaluate problems with multiple anisotropic layersDeveloped to evaluate problems with multiple anisotropic layers

Equivalent magnetic source [30, Benalla]Equivalent magnetic source [30, Benalla]► Field expression are much simplerField expression are much simpler► Numerical integration and derivatives are extensiveNumerical integration and derivatives are extensive► Needs to be extended to evaluate the problems proposed hereNeeds to be extended to evaluate the problems proposed here

Spectral domain immittance method [16, Nelson]Spectral domain immittance method [16, Nelson]► Derivation is lengthyDerivation is lengthy► Needs to be developed to compute mutual impedanceNeeds to be developed to compute mutual impedance► Numerical integration is niceNumerical integration is nice► No derivative approximationsNo derivative approximations► Developed to evaluate problems with multiple anisotropic materialsDeveloped to evaluate problems with multiple anisotropic materials

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Work PlanWork Plan►Validate numerical results for the Validate numerical results for the

isotropic case with commercially isotropic case with commercially available software.available software. Use Momentum in Advanced Design Use Momentum in Advanced Design

System (ADS) [64]. System (ADS) [64]. Reproduce printed dipole work by Rana Reproduce printed dipole work by Rana

and Alexopoulos [22].and Alexopoulos [22]. Reproduce rectangular microstrip results Reproduce rectangular microstrip results

by Pozar [11].by Pozar [11].[22] N.G. Alexopoulos and I.E. Rana, “Mutual impedance computation between printed dipoles,” IEEE Transactions on Antennas and Propagation, Vol. 29, No. 1, January 1981, pp. 106-112.[11] D.M. Pozar, “Input impedance and mutual coupling of rectangular microstrip antennas,” IEEE Transactions on Antennas and Propagation, Vol. 30, No. 6, November 1982, pp. 1191-1196.[64] www.agilent.com.

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Work PlanWork PlanMany significant results will be obtained Many significant results will be obtained

by looking at the previous problems in by looking at the previous problems in Momentum:Momentum: The problems will validate the numerically The problems will validate the numerically

extensive code using the spectral domain extensive code using the spectral domain immittance methodimmittance method

The new code can be used for multiple The new code can be used for multiple patch geometriespatch geometries

Momentum can be used as a good tool in Momentum can be used as a good tool in this type of researchthis type of research

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Work PlanWork Plan► Design and build a Design and build a

multiple layered multiple layered structure to measure structure to measure and validate the and validate the numerical calculations numerical calculations of input impedance and of input impedance and mutual coupling.mutual coupling. Jadlecka, Poe and Carver Jadlecka, Poe and Carver

[24] – measurement [24] – measurement techniquetechnique

Validates code with Validates code with measurementsmeasurements

[24] R.P. Jedlicka, M.T. Poe and K.R. Carver, “Measured mutual coupling between microstrip antennas,” IEEE Transactions on Antennas and Propagation, Vol. 29, No. 1, January 1981. 21/25

Initial workInitial work►Derivation of the immittance functions Derivation of the immittance functions

for the single layer isotropic casefor the single layer isotropic case►Polar and rectangular integration of Polar and rectangular integration of

the immittance functions have been the immittance functions have been started and compare well with started and compare well with Nelson’s Fortran resultsNelson’s Fortran results

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Significance of anticipated Significance of anticipated resultsresults

► Mutual impedance will significantly effect input Mutual impedance will significantly effect input impedance of driven elementsimpedance of driven elements

► Appropriate values of permittivity could possibly Appropriate values of permittivity could possibly minimize mutual impedance (Krowne [17] and Wang minimize mutual impedance (Krowne [17] and Wang [62])[62])

► Possible reduction of array surface areaPossible reduction of array surface area Values of permittivityValues of permittivity Conducting surface on multiple layersConducting surface on multiple layers

► UWB antennasUWB antennas► 60GHz-90GHz band60GHz-90GHz band► Dual frequency antennasDual frequency antennas► RFID systemsRFID systems [17] C.M. Krowne, “Green's function in the spectral domain for biaxial and uniaxial anisotropic planar

dielectric structures,” IEEE Transactions on Antennas and Propagation, Vol. 32, No. 12, December 1984.[62] W.J. Wang, “Multilayered printed antennas with biaxial anisotropic dielectric substrates: general analysis and case studies,” Ph.D. Dissertation, Polytechnic University, January 2002.23/25

ConclusionConclusion► A method for investigating the input A method for investigating the input

impedance and mutual coupling of multiple impedance and mutual coupling of multiple microstrip antennas on multiple anisotropic microstrip antennas on multiple anisotropic layers is presented.layers is presented.

► Based on the spectral domain immittance Based on the spectral domain immittance methodmethod

► Areas of interest includeAreas of interest include RFIDRFID Microstrip arrays – UWB, dual frequncy, … .etcMicrostrip arrays – UWB, dual frequncy, … .etc EMCEMC

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Questions?Questions?

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