Generation of Free Space Radiation Patterns From Non-Anechoic Measurements Using Chebyshev Polynomials

Generally, antenna radiation patterns are measured in an anechoic condition so that the presence of undesired reflections does not skew the final measurements. The objective of this communication is to search for methodologies which can extract meaningful approximate results from non-anechoic measurements. In other words, how to process the reflection contaminated data and extract valuable information when one does not have a good anechoic room and performs measurements with various undesired reflections present in the data. The Chebyshev polynomials are used to extract from the data collected under non-anechoic environment and generate a radiation pattern for the same antenna radiating in free space conditions. The problem with this method is that some a priori information is required about the environment. Measured data has been used to illustrate the applicability of this new methodology and its improved performance over the FFT based methods.