Improving Measurement Results by Applying Hybrid Compact Range Modelling Methods

The Compact Antenna Test Range (CATR) principle generates pseudo far-field conditions in a limited test-zone volume of an anechoic chamber, referred to as quiet-zone (QZ). It allows accurate real-time far-field radiation pattern measurements of antennas at relatively short distance indoor under controlled conditions. In a range assessment, the error sources are determined to qualify the measurement uncertainty. Considering the stringent requirements on measurement accuracy for present needs, direct application of a CATR is sometimes questionable. To reduce the errors that are related to the CATR principle, prior knowledge of amplitude and phase characteristics across the test-zone are required for performing an accurate calibration of the measurements. Both measurement and simulation methods have been presented in the past to characterize the test-zone, but have specific advantages and drawbacks. This paper shows how to overcome the limitations of the both using hybrid Compact Range modelling methods. Existing measurement techniques and simulations approaches, as full-wave and asymptotic methods, are presented. Each of them can be used stand alone or combined in a subsequent hybrid modelling step to evaluate the current system status. Methods are applied to a measured dataset of a corrugated X-band horn antenna to proof the concept.