Title :
The Stochastic Gabor Function Enhances Bandwidth In Finite-Difference-Time Domain
-Parameter Estimation
Author :
Bonmassar, Giorgio
Author_Institution :
Martinos Center for Biomed. Imaging, Harvard Med. Sch., Charlestown, MA
fDate :
4/1/2007 12:00:00 AM
Abstract :
This paper introduces the stochastic Gabor function, an excitation waveform that can be used for finite-difference time-domain S-parameter estimation. The stochastic Gabor function is a Gaussian function modulated by uniformly distributed noise; it has wide frequency spectrum representation regardless of the stimuli pulse length. The stochastic Gabor function was studied in the time-frequency domain and was compared to Gaussian and Gabor stimuli functions with the same length. As shown by frequency concentration measurements, the stochastic Gabor function is least compact in the sample frequency phase plane. Numerical results obtained by using a multilayer stripline indicate that the stochastic Gabor function provides convergence and stability similar to those provided by the Gabor and Gaussian functions, but produces a much wider frequency band response when used as a pointwise hard voltage source stimulus
Keywords :
Gaussian processes; S-parameters; finite difference time-domain analysis; strip lines; waveguide theory; Gabor stimuli functions; Gaussian function; excitation waveform; finite-difference-time domain S-parameter estimation; frequency concentration measurements; frequency spectrum representation; multilayer stripline; noise generators; pulse-shaping methods; source excitation; stimuli pulse length; stochastic Gabor function; time-frequency domain; uniformly distributed noise; Bandwidth; Finite difference methods; Frequency measurement; Gaussian noise; Pulse modulation; Scattering parameters; Stochastic processes; Stochastic resonance; Time domain analysis; Time frequency analysis; Noise generators; pulse-shaping methods; source excitation;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2007.892806