# December 2005, Volume 14, Number 4

**P. Hazdra, M. Polivka, V. Sokol**
[references] [full-text]

Microwave Antennas and Circuits Modeling Using Electromagnetic Field
Simulator

Electromagnetic field simulators have become a widely used tool in a design process of microwave circuits and systems. A proper usage of electromagnetic (EM) field simulators allows substantial reduction of the design time providing reliable results. In such case the required parameters of the designed circuit can be reached even at the first manufactured prototype in spite of high complexity of the structure. However, EM simulation as a numerical process suffers from systematic and random errors similar to measurement using real equipment. Thus the setting of the EM-field simulator such as a frequency range, mesh properties, usage of PEC and PMC walls etc. has to be done with the highest attention and the simulation results have to be always verified using well-established techniques. The aim of the paper is to demonstrate the selected capability of EM-field simulators with a few examples of antenna and circuit modeling. Also an issue of reliability and simulation errors will be discussed.

- SWANSON, D. G. Jr., W. J. R HOEFER, W. J. R. MicrowaveCircuit Modeling Using Electromagnetic Field Simulation. London:Artech House, 2003.
- HARRINGTON, R. F. Field Computation by Moment Methods. NewYork: Macmillan, 1968.
- BURKE, G. J., POGGIO, A. J. Numerical Electromagnetic Code(NEC-2). Lawrence Livermore Laboratory, 1981.
- SILVESTER, P. P. Finite element analysis of planar microwavenetworks. IEEE Transactions on Microwave Theory and Techniques.1973, vol. 21, no. 2, p. 104-108.
- SILVESTER, P. P., FERRARI, R. L. Finite Elements for ElectricalEngineers. 3/E. New York: Cambridge University Press, 1996.
- MOSIG, J. Integral equation technique. Chapter 3 of NumericalTechniques for Microwave and Millimeter-Wave Passive Structures.Itoh, T. (ed.). New York: John Wiley & Sons, 1989.
- www.zeland.com
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- http://eesof.tm.agilent.com/
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- YEE, K. S. Numerical solution of initial boundary-value probleminvolving Maxwell's equations in isotropic media. IEEE Transactionson Antennas and Propagation. 1966, vol. 14, no. 5, p. 302-307.
- KUNZ, K. S, LUEBBERS, R. L. The Finite Difference Time DomainMethod for Electromagnetics. Boca Raton: CRC Press, 1993.
- MAFIA, Computer Simulation Technology (CST), Darmstadt,Germany.
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- HOEFER, W. J. R. The transmission line matrix (TLM)." Chapter 8of Numerical Techniques for Microwave and Millimeter-WavePassive Structures. ITOH, T. (ed.). New York: John Wiley & Sons,1989.
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- www.semcad.com
- www.empire.de
- www.zeland.com
- http://www.qwed.com.pl/
- www.faustcorp.com
- POLIVKA, M., DRAHOVZAL M., MAZANEK, M. Synthesis ofdualband broadside radiated microstrip patch antenna operating withTM10 and TM21 modes. In Proceedings of Antenna and PropagationSymposium APS 2004. Monterey (USA), 2004, p. 245-248.
- GARG. R., BHARTIA, P. Microstrip Antenna Design Handbook.Norwood: Artech House, 2000.
- NAISHADHAM, W. K., DURAK, T. Measurement-based closedformmodelling of surface-mounted RF components. IEEE Trans. onMicrowave Theory and Techn. 2002, vol. 50, no. 10, p. 2276-2286.
- HOFFMANN, K. Planar Microwave Circuits. Textbook of CzechTechnical University in Prague (in Czech), 2000.
- CST Microwave Studio Advanced topics manual, version 5, 2003.
- SOKOL, V. 3-D Components in Microwave Planar Circuits. DissertationThesis (in Czech). Czech Technical University, 2004.
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- BIANCO, B., PANINI, L., PARODI, M., RIDELLA, S. Someconsiderations about the frequency dependence of the characteristicimpedance of uniform microstrips. IEEE Transactions on MicrowaveTheory and Techniques. 1978, vol. 26, no. 3, p. 182-185.
- SOKOL, V., CERNY, P., HOFFMANN, K., SKVOR, Z. Assessmentof reference planes location for 3-D components in planar structures.In ITSS 2004 - Summer School Proceedings. Brno (Czech Republic),2004, p. 377-381.

**A. Cap, Z. Raida, E. de la Heras Palmero, R. Lamadrid, Ruiz**
[references] [full-text]

Multi-Band Planar Antennas: a Comparative Study

In the paper, four different planar multi-band antennas are
designed, modeled, fabricated, and measured. Parameters of the antennas
are in detail compared to demonstrate advantages and disadvantages of
different solutions. Discussions are supported by results of the modal
and full-wave analyses of antennas.

The classical patch antenna is a basic building block of compared
antennas. The multi-band behavior is achieved by etching perturbation
slots to the patch, which influence resonant current distributions.

The antennas are designed for GSM bands (900 MHz, 1 800 MHz), and
for the Bluetooth band (2 400 MHz).

- GARG, B., BAHL, I. Microstrip Antenna Design Handbook. Norwood:Artech House, 2001.
- KUMAR, G., RAY, K. P. Broadband Microstrip Antennas. Norwood:Artech House, 2003.
- WONG, K. L. Compact and Broadband Microstrip Antennas. NewYork: J. Wiley and Sons, 2002.
- NAKANO, H., SATO, Y., HIROAKI, M., YAMAUCHI, J. An invertedFL antenna for dual-frequency operation. IEEE Transactionson Antennas and Propagation. 2005, vol. 53, no. 8, p. 2417-2421.
- NASHAAT, D. M., ELSADEK, H. A., GHALI, H. Single feed compactquad-band PIFA antenna for wireless communication applications.IEEE Transactions on Antennas and Propagation. 2005, vol.53, no. 8, p. 2631-2635.
- ZHAN, L., RAHMAT-SAMII, Y. Optimization of PIFA-IFA combinationin handset antenna designs. IEEE Transactions on Antennasand Propagation. 2005, vol. 53, no. 5, p. 1770-1778.
- LATIF, S. I., SHAFAI, L., SHARMA, S. K. Bandwidth enhancementand size reduction of microstrip slot antennas. IEEE Transactions onAntennas and Propagation. 2005, vol. 53, no. 3, p. 994 to 1003.
- ROW, J. S. Dual-frequency triangular planar inverted-F antenna.IEEE Transactions on Antennas and Propagation. 2005, vol. 53, no.2, p. 874-876.
- MOLEIRO, R., NUNES, P. Dual-band microstrip patch antennaelements for GSM. In Proceedings of the Antennas and PropagationSociety International Symposium. 2000, vol. 3, p. 1596-1599.
- POLIVKA, M., DRAHOVZAL, M., MAZANEK, M. Synthesis ofdualband broadside radiated microstrip patch antenna operating withTM_10 and TM_21 modes. In Proceedings of the 2004 IEEE Antennasand Propagation Society International Symposium. Monterey(CA, USA), 2004, p. 245-248.
- POLIVKA, M. Multiband behavior of the rectangular microstrippatch antenna modified by T notch perturbation elements. In Proceedingsof the 18th International Conference on Applied Electromagneticsin Communications ICECom 2005. Dubrovnik (Croatia):KOREMA, 2005, p. 185-188.
- HAZDRA, P. Numerical analysis of microstrip patch antennas withfractal boundary. In POSTER 2002 - Book of Extended Abstracts.Prague : CTU - Faculty of Electrical Engineering, 2002, p. C10.
- HAZDRA P., MAZANEK, M. Planar patch antennas with fractalboundary. In Proceedings of ISAP 2004. Sendai (Japan), 2005, p.401-404.
- http://www.cst.com/ - the home site of Computer Simulation TechnologyLtd.
- http:://www.zeland.com - the home site of Zeland Software Inc.

**J. Holis, P. Pechac**
[references] [full-text]

Simulation of UMTS Capacity and Quality of Coverage in Urban Macro- and
Microcellular Environment

This paper deals with simulations of a radio interface of third generation (3G) mobile systems operating in the WCDMA FDD mode including propagation predictions in macro and microcells. In the radio network planning of 3G mobile systems, the quality of coverage and the system capacity present a common problem. Both macro and microcellular concepts are very important for implementing wireless communication systems, such as Universal Mobile Telecommunication Systems (UMTS) in dense urban areas. The aim of this paper is to introduce different impacts - selected bit rate, uplink (UL) loading, allocation and number of Nodes B, selected propagation prediction models, macro and microcellular environment - on system capacity and quality of coverage in UMTS networks. Both separated and composite simulation scenarios of macro and microcellular environments are presented. The necessity of an iteration-based simulation approach and site-specific propagation modeling in microcells is proven.

- LAIHO, J., WACKER, A., NOVOSAD, T. Radio Network Planningand Optimization for UMTS. New York: John Wiley & Sons, 2001.
- BERG, J-E: A. Recursive method for street microcell path loss calculation.In Proceedings of the IEEE International Symposium onPersonal, Indoor and Mobile Radio Communications PIMRC'95.1995, vol. 1, p. 140-143.
- COST Action 231 Final Report: Digital Mobile Radio, Towards FutureGeneration Systems, 1999.
- ETSI: Selection Procedures for the Choice of the Radio TransmissionTechnologies of UMTS (UMTS 30.30 version 3.1.0), Nov 1997.
- HOLIS, J., PECHAC, P. Effective propagation prediction in urbanmicrocells. In Proceedings of the International Wireless Summit2005. Aalborg (Denmark), 2005.
- HOLMA, H., TOSKALA, A. WCDMA for UMTS radio access forthird generation mobile networks. New York: John Wiley & Sons,2000.
- HOLIS, J., PECHAC, P. Iteration-based simulations of UMTS capacityand quality of coverage in high altitude platform basic scenarios.COST 297. Athens (Greece), 2005.

**G. Timms, V. Kvicera, M. Grabner**
[references] [full-text]

60 GHz Band Propagation Experiments on Terrestrial Paths in Sydney and
Praha

Two studies of the outdoor propagation of 60 GHz microwaves are described. The focus of this paper is the relationship between rainfall and measured attenuation of the microwave signal. Experimental data are presented and the measured statistics are compared with the Recommendations of the ITU-R. Measured rain intensity statistics at the two sites were found to be in good agreement with the ITU-R Recommendations, however measured attenuations were higher than those calculated using the models provided by the ITU-R.

- ASEN, W., TJELTA, T. A novel method for predicting site dependentspecific rain attenuation of millimeter radio waves. IEEETrans. on Antennas and Prop., 2003, vol. 51, no. 10, p. 2987-2999.
- ASEN, W., GIBBINS, C. J. A comparison of rain attenuation anddrop size distributions measured in Chilbolton and Singapore. RadioScience, 2002, vol. 37, no. 3, p. 6-1 to 6-14.
- MANABE, T., IHARA, T., AWAKA, J., FURUHAMA, Y. Therelationship of raindrop-size distribution to attenuations experiencedat 50, 80, 140 and 240 GHz. IEEE Transactions on Antennas andPropagation, 1987, vol. 35, no. 11, p. 1326-1330.
- VEYRUNES, O., LE CLERC, P., SIZUN, H. Results of millimetrewave propagation analysis. In Millennium Conference on Antennasand Propagation AP-2000. Davos (Switzerland), 2000, p. 61.
- Rec. ITU-R P.837-4 Characteristics of precipitation for propagationmodelling. ITU, [CD-ROM], Geneva (Switzerland), April 2003.
- Rec. ITU-R P.530-11 Propagation data and prediction methodsrequired for the design of terrestrial line-of-sight systems. ITU, [CDROM],Geneva (Switzerland), March 2005.
- TIMMS, G. P., ABBOTT, D. A., DYADYUK, V., STOKES, L.Early results of a rain attenuation study in the 60 GHz band. In Proceedingsof the 6th Topical Symposium on Millimeter Waves(TSMMW 2004). Yokosuka (Japan), 2004, pp. 159-162.
- Monthly Meteorological Summaries from Observatory Praha -Karlov. Czech Hydrometeorological Office, Praha, 2004.
- Rec. ITU-R P.841-4 Conversion of annual statistics to worst monthstatistics. ITU, [CD-ROM], Geneva (Switzerland), March 2005.
- KVICERA, V., CEJKA, P. 50-year cumulative distributions of rainintensities in the Czech Republic (average year, average worstmonth, extremes, stability, periodicity). In Proceedings of the FirstInternational Workshop on Radiowave Propagation Modelling forSatCom Services at Ku-Band and above. ESTEC, Noordwijk (TheNetherlands), 1998, pp. 147-154.
- KVICERA, V., GRABNER, M., HLAVATY, M. Rain intensitystatistical processing and comparison with ITU-R Recommendations.In Radioengineering, 2004, vol. 13, no. 2, pp. 1-2.
- FISER, O. Examples of rain gauge data analysis for microwave rainattenuation estimation. 3rd International Workshop of the COSTAction 280, Praha, 2005, http://www.cost280.rl.ac.uk.

**D. Bonefacic, J. Bartolic**
[references] [full-text]

Design Considerations of an Active Integrated Antenna with Negative
Resistance Transistor Oscillator

The design of an active integrated antenna with negative resistance transistor oscillator has been described. Simple but reasonably accurate analysis of oscillation start-up and steady state operating frequency prediction is presented. The active antenna prototype was manufactured and its operating frequency, EIRP and radiation patterns were measured. Two of these antennas were integrated in active arrays coupled in E- and H-planes. The inter-element distance in the arrays was optimized to obtain in-phase operation and mutual injection locking. Very good power combining efficiency was measured and beam scanning capabilities were demonstrated for both arrays.

- KYKKOTIS, C., HALL, P.S., GHAFOURI-SHIRAZ, H. Performanceof active antenna oscillator arrays under modulation forcommunication systems. IEE Proceedings - Microwaves, Antennasand Propagation, 1998, vol. 145, no. 4, p. 313-320.
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- YORK, R.A., COMPTON, R.C. Quasi-optical power combining usingmutually synchronized oscillator arrays. IEEE Transactions on MicrowaveTheory and Techniques, 1991, vol. 39, no. 6, p. 1000-1009.
- MURATA, M., MATSUI, T. 2×2 spatial power combining array ofplanar radiating oscillator using butterfly-shaped patch element. InProceedings of the 29th European Microwave Conference. Munich(Germany), 1999, vol. 2, p. 201-204.
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- BARTOLIC, J., BONEFACIC, D., SIPUS, Z. Modified rectangularpatch array with electronic beam scanning. In Proceedings of the 14thInternational Conference on Applied Electromagnetics and Communications(ICECOM'97). Dubrovnik (Croatia), 1997, p. 67-70.
- YORK, R.A. Nonlinear analysis of phase relationships in quasiopticaloscillator arrays. IEEE Transactions on Microwave Theoryand Techniques, 1993, vol. 41, no. 10, p. 1799-1809.
- LIN, J., ITOH, T. Two-dimensional quasi-optical power-combiningarrays using strongly coupled oscillators. IEEE Transactions on MicrowaveTheory and Techniques, 1994, vol. 42, no. 4, p. 734-741.
- RAHMAN, M., IVANOV, T., MORTAZAVI, A. A 26-MESFETspatial power-combining oscillator. IEEE Microwave and GuidedWave Letters, 1997, vol. 7, no. 4, p. 100-102.
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- MARTINEZ, R.D., COMPTON, R.C., High-efficiency FET/microstrip-patch oscillators. IEEE Antennas and Propagation Magazine,1994, vol. 36, no, 1, p. 16-19.
- KUROKAWA, K., Injection locking of microwave solid-stateoscillators. Proceedings IEEE, 1973, vol. 61, no. 10, p. 1386-1410.
- BARTOLIC, J., BONEFACIC, D., SIPUS, Z. Modified rectangularpatches for self-oscillating active antenna applications. IEEE Antennasand Propagation Magazine, 1996, vol. 38, no, 4, p. 13-21.
- -, AT-41485, Up to 6 GHz Low Noise Silicon Bipolar Transistor -Technical Data. Hewlett-Packard Co., USA, 1997.
- BALANIS, C.A. Antenna Theory: Analysis and Design. 2nd ed.New York: John Wiley, 1997.

**M. Polivka, A. Holub, M. Mazanek**
[references] [full-text]

Collinear Microstrip Patch Antenna

The paper presents a brief overview of the development of so called collinear types of antenna arrays. A new type of this structure in microstrip technology is further introduced. The principle of the antenna operation is explained via surface current distribution of excited modes. Such distribution is reached via geometrical perturbation of a radiating element by slots introduced in such a way that they e liminate radiation from even half current wavelengths . The initial design and optimization of the prototype operating in RFID band (869 MHz) has been performed in planar simulator Zeland IE3D. A prototype has been realized and measured. The reached results show that the presented antenna has directional character as it can be expected due to the proposed technology and the presence of a planar ground plane.

- FRANKLIN, C. S. Brit. Patent 242342-1924, 1924.
- JUDAZS, T. J., BALSLEY, B. B. Improved theoretical and experimentalmodels for the coaxial collinear antenna. IEEE Trans. Antennasand Propagat. 1989, vol. 37, p.289-296.
- SOLBACH, K. Microstrip-Franklin Antenna. IEEE Trans. Antennasand Propagat. 1982, vol. 30, no. 4, p. 773-775.
- CERNOHORSKY, D., NOVACEK, Z., Dipole array excited by slotsin its coaxial feeder. Radioengineering. 2001, vol. 10, no. 4,p. 9-16.
- BANCROFT, R., BATEMAN, B.. An omnidirectional planar microstripantenna. IEEE Trans. Antennas and Propagat. 2004, vol. 52,no. 11, p. 3151-3153.
- POLIVKA, M., HOLUB, A. CZ Patent Application PUV 2005-396,2005.
- MAZANEK, M., KLEPAL, M., PECHAC, P., POLIVKA, M., BARTIK,H. Anechoic and EMC chambers - modelling, design, testing.In Proc. of the Millennium Conference on Antennas and Propagation.Noordwijk, European Space Agency, 2000, vol. 2, p. 156-160.
- GARG. R., BHARTIA, P. Microstrip Antenna Design Handbook.,Artech House, 2000.

**L. Januszkiewicz, M. Czarnecki**
[references] [full-text]

Simulation of a Broadband Antenna with the Method of Moments

In the paper selected problems of computer simulations of a broadband antenna containing large metallic surfaces with the Method of Moments have been discussed. A novel broadband combined spiral-discone antenna, built of a complementary spiral and a cone has been analyzed. Since the antenna contains large metallic surfaces wire-grid models had to be developed in order to simulate the antenna with the thin-wire kernel method of moments. Several wire-grid models of the antenna have been proposed and analyzed. The simulation results for input impedance have been compared to those obtained from measurements and the best model of the antenna has been identified.

- RICHMOND, J. H. A wire grid model for scattering by conductingbodies. IEEE Transactions on Antenna and Propagation. 1966, vol.AP-14, no. 6, pp. 782-786.
- LUDWIG, A. C. Wire grid modeling of surfaces. IEEE Transactionson Antennas and Propagation. 1987, vol. AP-35, no. 9, pp. 1045-1048.
- KOLUNDZIJA, B. M., MIODRAG, T. S., DJORDJEVIC, A. R.Optimal wire-grid modeling based on conversion of solid surfacemodel. In Proc. IEEE AP-S Symp. Boston (USA), 2001, vol. 2, pp.592-595.
- JANUSZKIEWICZ, L., HAUSMAN, S. Combined spiral-disconebroadband antenna for indoor applications. In IEEE PIMRiC.Barcelona (Spain), 2004, vol.1, pp. 422- 426.
- FOURIE, A., NITCH, D. SuperNEC: Antenna and indoor -propagation simulation program. IEEE Antennas and PropagationMagazine. 2000, vol. 42, no. 3, pp. 31-48.
- TRUEMAN, C.W., KUBINA, S. J. Fields of complex surfaces usingwire grid modelling. IEEE Transactions on Magnetics. 1991, vol. 25,no 5, pp. 4162 - 4267.

**M. Motl, Z. Raida**
[references] [full-text]

Broadband Analysis of Microwave Structures by Enhanced Finite-Element
Methods

The paper deals with the broadband modeling of microwave structures
by finite-element methods. The attention is turned to original
enhancements of accuracy, efficiency and stability of finite-element
codes.

The partial improvements are based on novel approximations both in the
spatial domain and in the time one, in the adoption of complex
frequency hopping, fast frequency sweep and envelope finite-element
techniques. In the paper, a possible hybridization of approaches is
discussed.

Proposed finite-element schemes are applied to the analysis of
canonical longitudinally homogeneous transmission lines in order to
demonstrate their advantages.

- CERNOHORSKY, D., RAIDA, Z., SKVOR, Z., NOVACEK, Z.Analyza a optimalizace mikrovlnnych struktur (Analysis and Optimizationof Microwave Structures). Brno: VUTIUM Publishing,1999.
- VOLAKIS, J. L., CHATTERJEE, A., KEMPEL, L. C. Fininte ElementMethod for Electromagnetics. New York: IEEE Press, 1998.
- SILVESTER, P. P., FERRARI, R. L. Finite Elements for ElectricalEngineers. Cambridge: Cambridge University Press, 1996.
- RAIDA, Z., TKADLEC, R., FRANEK, O., MOTL, M., LACIK, J.,LUKES, Z., SKVOR, Z. Analyza mikrovlnnych struktur v casoveoblasti (Time-Domain Analysis of Microwave Structures). Brno:VUTIUM Publishing, 2003.
- LEE, J.-F., LEE, R., CANGELLARIS, A. Time-domain finite elementmethods. IEEE Transactions on Antennas and Propagation.1997, vol. 45, no. 3, p. 430-441.
- MOTL, M., FRANEK, O., RAIDA, Z. Comparison of time-domainfinite element (TD-FE) and finite-difference time-domain (FDTD)methods. In Proceedings of the International Symposium on AntennasJINA 2002. Nice (France): S.E.E GReCA, 2002, p. 79-82.
- TAFLOVE, A. Computational Electrodynamics: The Finite-DifferenceTime-Domain Method London: Artech House Publishing,1995.
- TAFLOVE, A. Advances in Computational Electrodynamics: TheFinite-Difference Time-Domain Method. Boston: Artech House Publishing,1998.
- YEE, K. S. Numerical solution of initial boundary value problemsinvolving Maxwell's equations in isotropic media. In IEEE Transactionson Antennas and Propagation. 1966, vol. 14, no. 3, p. 302 to307.
- JIN, J The Finite Element Method in Electromagnetics. New York:John Wiley & Sons, 2002.
- LEE, J. F., SUN, D. K., CENDES, Z. J. Full-wave analysis of dielectricwaveguides using tangential vector finite-elements. IEEE Transactionson Microwave Theory and Techniques. 1991, vol. 39, no. 8,p. 669-678.
- LEE, J. F. Finite element analysis of lossy dielectric waveguides.IEEE Transactions on Microwave Theory and Techniques. 1994, vol.42, no. 6, p. 1025-1031.
- DUDLEY, D. G. Mathematical Foundations for ElectromagneticTheory. Piscataway: IEEE Press, 1994.
- CHEW, W. C., NASIR, M. A. A variational analysis of anisotropic,inhomogeneous dielectric waveguides. IEEE Transactions on MicrowaveTheory and Techniques. 1989, vol. 37, no. 4, p. 661-668.
- KOLBEHDARI, M. A., SRINIVASAN, M., NAKHLA, M. S.,ZHANG, Q.-J., ACHAR, R. Simultaneous time and frequency domain solutions of EM problems using finite element and CFH techniques.IEEE Transactions on Microwave Theory and Techniques.1996, vol. 44, no. 9, p. 1526-1533.
- RAIDA, Z. Finite-element complex-hopping analysis of microwavewaveguides. In Proceedings of the International Conference onElectromagnetics in Advanced Applications ICEAA '97. Torino: Polytechnicodi Torino (Italy), 1997, vol. 1, p. 163-166.
- WANG, Y., ITOH, T. Envelope finite element (EVFE) techniques -A more efficient time-domain scheme. IEEE Transactions on MicrowaveTheory and Techniques. 2001, vol. 49, no. 12, p. 2241-2247.
- TSAI, H. P., WANG, Y., ITOH, T. Efficient analysis of microwavepassive structures using 3-D envelope finite element (EVFE). IEEETransactions on Microwave Theory and Techniques. 2002, vol. 50,no. 12, p. 2721-2727.
- FRASSON, A. M. F., HERNANDEZ FIGUEROA, H. E. Envelopefull-wave 3D finite element time domain method. Microwave andOptical Components Letters. 2002, vol. 35, no. 5, p. 351-354.
- JONES, D. C. Methods in Electromagnetic Wave Propagation. Oxford:Clarendon Press, 1979.
- MOTL, M. Analysis of Microwave Structures by Variational Approaches.Dissertation Thesis. Brno: Brno University of Technology,2005.
- MOTL, M. High order approximation for finite element method infrequency and time domain. In Proceedings of the 12th InternationalTravelling Summer School on Microwaves & Lightwaves. Minsk:Institute of Electronics of National Academy of Sciences of Belarus,2002, p. 240-246.
- WEBB, J. P., FORGHANI, B. Edge elements and what they can dofor you. IEEE Transactions on Magnetics. 1993, vol. 29, no. 2, p.1460-1465.
- MOTL, M. Higher-order algorithm in time-domain finite elementmethod. In Proceedings of the 10th conference Student EEICT 2004.Brno: Brno University of Technology, 2004, p. 114-118.
- POULARIKAS, A. D. The Transforms and Applications Handbook.Electrical Engineering Handbook Series. 2/E. Boca Raton: CRCPress, 2000.
- MOTL, M., FRANEK, O., RAIDA, Z. Comparison of finite elementcomplex frequency hopping (FE/CFH) and finite-difference timedomain(FDTD) methods. In Proceedings of the International ScientificConference Radioelektronika 2002. Bratislava: Slovak Universityof Technology, 2002, p. 70-73.
- MOTL, M., RAIDA, Z. Comparison of finite element complex frequencyhopping (FEM/CFH) and time-domain finite element (TDFEM)methods. In Proceedings of the International Scientific ConferenceRadioelektronika 2003. Brno: Brno University of Technology,2003, p. 264-267.
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**H. Bartik**
[references] [full-text]

Antenna Measurements Using the Mirror Method with Gating in a Time
Domain

This paper provides a principal overview of the time domain measurement instrumentation and information about the implementation of the time domain option in the Agilent PNA microwave network analyzer E8364A. The paper also presents practical experiences with antenna measurements realized by sweep mode of a vector network analyzer with data processing in a time domain. The new single antenna methods of gain and antenna radiation patterns measurements are presented. These mirror methods with gating in a time domain are based on the reflection coefficient measurements realized in the frequency domain with time domain data processing. These methods seem to be promising for measurements of gain and radiation patterns of ultra-wideband linearly polarized antennas. The paper compares the results of the new methods with the results of standard measurements.

- BRUMLEY S. Pulsed and chirped measurement techniques. AMTAEurope Short Course, Munich (Germany), 2004.
- PNA Series Network Analyzer Help, Agilent Technologies, 2003.
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- BARTIK, H. Antenna gain measurement using the mirror method intime domain. WSEAS Transactions on Computers, 2004, vol. 3, p.1882-1883.
- Double Ridged Waveguide Horn - Model DRH18E, www.rfspin.cz,2005.

**R. Tkadlec, Z. Novacek**
[references] [full-text]

Radiation Pattern Reconstruction from the Near-Field Amplitude
Measurement on Two Planes Using PSO

The paper presents a new approach to the radiation pattern reconstruction from near-field amplitude only measurement over a two planar scanning surfaces. This new method for antenna pattern reconstruction is based on the global optimization PSO (Particle Swarm Optimization). The paper presents appropriate phaseless measurement requirements and phase retrieval algorithm together with a brief description of the particle swarm optimization method. In order to examine the methodologies developed in this paper, phaseless measurement results for two different antennas are presented and compared to results obtained by a complex measurement (amplitude and phase).

- ISERNIA, T., LEONE, G., PIERRI, R. Radiation pattern evaluationfrom near-field intensities on planes. IEEE Transactions on Antennasand Propagation. 1996, vol. 44, no. 5, p. 701-710.
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- TKADLEC, R. Determination of far-field antenna pattern from nearfieldplanar measurements. In Proceedings of the Conference Radioelektronika2003. Brno: Brno University of Technology. 2003, p.229-231, ISBN 80-214-2383-8.
- KENNEDY, J., EBERHART, R. C. Particle swarm pptimization. InProceedings of the IEEE Conference on Neural Networks IV, Piscataway,NJ, 1997
- ROBINSON, J., RAHMAT-SAMII, Y. Particle swarm in electromagnetics.IEEE Transaction on Antennas and Propagation. 2004,vol. 52, no. 2, p. 397-407.
- BARTIK, H., Antenna radiation patterns measurement using themirror method in time domain. In Proceedings of the ISAP 2005.Seoul, 2005, p. 1221-1224.
- KONDAPANEMI, F., BARTIK, H., Far field method antenna measurementsin near field. In Proceedings of the conference Radioelektronika2005. Brno: Brno University of Technology, 2005.

**L. Vegni, A. Toscano**
[references] [full-text]

Shielding and Radiation Characteristics of Cylindrical Layered
Bianisotropic Structures

In this paper we propose an analytical study in the spectral domain of cylindrical layered structures filled with general bianisotropic media and fed by a 3D electric source. The integrated structure is characterized in terms of transmission matrices leading to an equivalent circuit representation of the whole multilayered structure. Within the framework of this two-port formalism, we present a new contribution to the computation of the Green's function arising in the analysis of multilayered conformal integrated antennas loaded with general bianisotropic materials. We also propose an analytical study of the shielding effectiveness of general bianisotropic materials located in multilayered, cylindrical configuration. The expression of the shielded fields sustained both by plane wave and arbitrary sources is obtained in a closed analytical form. Numerical results are also presented showing effects of electromagnetic parameters on radiation pattern, matching properties and radar cross section of the integrated structure.

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**V. Sokol, P. Cerny, K. Hoffmann, Z. Skvor**
[references] [full-text]

Assembly Influence on the Small-Signal Parameters of a Packaged
Transistor

A detailed analysis of the assembly influence on the small-signal parameters of a packaged transistor is presented. A new method, based on 3D field simulation and mixed-mode scattering parameters approach is proposed. Differences in scattering parameters caused by assembly change are computed using the new proposed method and compared to the standard method based on admittance matrix. The differences, accuracy, error sources and suitability of both methods are discussed. Results are verified experimentally in microstrip line for two fundamental assembly changes of a transistor in SOT 343 package in frequency range 45 MHz - 18 GHz.

- BRAZIL, T. J. Simulating circuits and devices. IEEE MicrowaveMagazine, March 2003, pp 42-50.
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**V. Wieser, V. Psenak**
[references] [full-text]

BER and SIR Based Hybrid Link Algorithms Performance in Mobile Radio
Channel

In the next generation of mobile communication networks (B3G) the using of effective handling of radio resources is supposed (channels, power and transmission rate) with simultaneous delivery of required services, in which the quality of service (QoS) is guaranteed. In this article we have described and simulated new BER based, SIR-frame based and SIR-slot based link adaptation algorithms. Algorithms were designed to increase efficiency of data transmission among user equipment and base stations (uplink) expressed by throughput and the outage probability for each link. Simulation results of hybrid adaptation (power and modulation BPSK, QPSK, 16-QAM, 64-QAM) are compared and expressed as data throughput and outage probability for different simulation environments (pedestrian channel with mobile subscriber speed 10 km/s and vehicular channel with speed 120 km/h).

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**V. Zavodny, K. Hoffmann, Z. Skvor**
[references] [full-text]

Seven State PTP for Vector Network Analyzer

A new, seven-state switched perturbation two-port (PTP) for vector reflection measurement based on scalar measurement only was designed and realized in microstrip structure using PIN diodes. The structure was experimentally tested by means of vector measurements of different impedances in frequency band with relative bandwidth of 2.5 octaves. Good agreement with data obtained using a precise vector network analyzer was achieved. The new calibration method for the PTP was designed and tested on real measured data.

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**Z. Lukes, Z. Raida**
[references] [full-text]

Multi-Objective Optimization of Wire Antennas: Genetic Algorithms
Versus Particle Swarm Optimization

The paper is aimed to the multi-objective optimization of wire
multi-band antennas. Antennas are numerically modeled using time-domain
integral-equation method. That way, the designed antennas can be
characterized in a wide band of frequencies within a single run of the
analysis. Antennas are optimized to reach the prescribed matching, to
exhibit the omni-directional constant gain and to have the satisfactory
polarization purity. Results of the design are experimentally verified.

The multi-objective cost function is minimized by the genetic algorithm
and by the particle swarm optimization. Results of the optimization by
both the multi-objective methods are in detail compared.

The combination of the time domain analysis and global optimization
methods for the broadband antenna design and the detailed comparison of
the multi-objective particle swarm optimization with the
multi-objective genetic algorithm are the original contributions of the
paper.

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**P. Valtr, P. Pechac**
[references] [full-text]

Tropospheric Refraction Modeling Using Ray-Tracing and Parabolic
Equation

Refraction phenomena that occur in the lower atmosphere significantly influence the performance of wireless communication systems. This paper provides an overview of corresponding computational methods. Basic properties of the lower atmosphere are mentioned. Practical guidelines for radiowave propagation modeling in the lower atmosphere using ray-tracing and parabolic equation methods are given. In addition, a calculation of angle-of-arrival spectra is introduced for multipath propagation simulations.

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**J. Machac, M. Hudlicka, P. Buchar, J. Zehentner**
[references] [full-text]

New Planar and Volume Versions of a Metamaterial

Some characteristics of materials with negative permittivity and permeability, i.e., with a negative refrative index, known as metamaterials, are presented in this paper. Dispersion characteristics of left-handed parallel strips calculated by different methods are compared with each other. The calculated and measured dispersion and transmission characteristics of a newly proposed left-handed coplanar waveguide and of a novel volume metmaterial are shown. Simple equivalent circuits of both structures are presented together with elements values. The structures exhibit a negative refractive index in a wide frequency band.

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