Analysis of antenna transient radiation

Recently a new formalism has been developed for modeling time domain radiation processes in complex antennas. Using this formalism the radiated electromagnetic field can be expressed in terms of non uniform spherical wave contributions relevant to the resonant phenomena occurring in the structure. The developed algorithm consists of a dedicated two-step vector fitting procedure. Firstly, the spherical harmonic expansion of the time-domain equivalent electric and magnetic currents is performed. Then, by using the Singularity-Expansion-Method (SEM), the time-variant spherical harmonic expansion coefficients are represented in terms of dumped exponential terms. In this way, by using the incomplete modified spherical Bessel functions, an analytical description of the transient wave radiation phenomena is achieved. In this study several canonical radiating structures such as dipole, bow-tie and loop antennas, have been analyzed using the afore-mentioned formalism in order to gain a physical insight into the natural resonant processes occurring in the antenna and find a relation with the relevant geometrical characteristics.

[1]  B. Gustavsen,et al.  Improving the pole relocating properties of vector fitting , 2006, 2006 IEEE Power Engineering Society General Meeting.

[2]  O. Bucci,et al.  Optimal interpolation of radiated fields over a sphere , 1991 .

[3]  T. Dhaene,et al.  Macromodeling of Multiport Systems Using a Fast Implementation of the Vector Fitting Method , 2008, IEEE Microwave and Wireless Components Letters.

[4]  M. Pausini.  Autocorrelation receivers for ultra wideband wireless communications , 2007 .

[6]  L. M. M.-T..  Spherical Harmonics: an Elementary Treatise on Harmonic Functions, with Applications , 1928, Nature.

[7]  Stefano Grivet-Talocia,et al.  Reduced-order macromodeling of complex multiport interconnects , 2002 .

[8]  S. Grivet-Talocia,et al.  Package macromodeling via time-domain vector fitting , 2003, IEEE Microwave and Wireless Components Letters.

[9]  A. Semlyen,et al.  Rational approximation of frequency domain responses by vector fitting , 1999 .

[11]  T. Sarkar,et al.  Using the matrix pencil method to estimate the parameters of a sum of complex exponentials , 1995 .

[12]  M. Ciattaglia,et al.  Approximate calculation of time-domain effective height for aperture antennas , 2005, IEEE Transactions on Antennas and Propagation.

[13]  Raphael Kastner,et al.  Antenna characterization in the time domain , 1997 .

[14]  G. Franceschetti,et al.  On the spatial bandwidth of scattered fields , 1987 .

[15]  A. Yarovoy,et al.  Unified time- and frequency-domain approach for accurate modelling of electromagnetic radiation processes in ultra-wideband antennas , 2009, 2009 European Microwave Conference (EuMC).

[16]  David B. Davidson,et al.  Computational Electromagnetics for RF and Microwave Engineering , 2005 .

[17]  Glenn S. Smith.  Teaching antenna radiation from a time-domain perspective , 2001 .

[18]  Kevin Barraclough,et al.  I and i , 2001, BMJ : British Medical Journal.

[19]  C. Balanis.  Antenna theory , 1982 .

[20]  Tapan K. Sarkar,et al.  Matrix pencil method for estimating parameters of exponentially damped/undamped sinusoids in noise , 1990, IEEE Trans. Acoust. Speech Signal Process..

[21]  Joseph Lipka,et al.  A Table of Integrals , 2010 .

[22]  L. Felsen,et al.  Radiation and scattering of waves , 1972 .

[23]  S. Licul,et al.  Unified frequency and time-domain antenna modeling and characterization , 2005, IEEE Transactions on Antennas and Propagation.

[24]  I. S. Gradshteyn,et al.  Table of Integrals, Series, and Products , 1976 .