COHERENT EFFECTS IN SINGLE SCATTERING AND RANDOM ERRORS IN ANTENNA TECHNOLOGY

Lack of knowledge prevents us from exactly calculating the behavior of electromagnetic fields. We study two extremes in this respect: scattering against randomly distributed particles ( no idea of the position or orientation of the scatterers), and random errors in antenna technology ( small deviations from what we think are the proper parameters). Random variables are used to model our lack of knowledge, and far field expressions are studied. Using the concept of characteristic functions from probability theory, results for arbitrary probability distributions are obtained. We explain an anomaly in the forward scattering direction in single scattering theory, present simple formulas for the directivity, side lobe level, and beam efficiency for a general array antenna with random errors, and a simple formula for the scattering coefficient from a general frequency selective structure with random errors