Sparse Aperture Measurement in a Non-Ideal Semi-Anechoic Chamber

Antenna aperture technology is a critical component of any radar system. The aperture of many early radar systems was composed of a a single antenna [1]. As technology advanced, single antenna apertures were replaced by electronically steered arrays for their ability to rapidly steer beams [2]. With the growth in processing capabilities, digitization at every element is becoming increasingly possible. With digitization at every element, array elements no longer must be co located, and instead can be arbitrarily sparse allowing increased ?exibility in resulting beam patterns. This capability is of extreme interest in recent years [3] [4] [5] [6].Key challenges in building arbitrarily sparse arrays is their calibration and measurement. Sparse array calibration becomes challenging in due to the nature of each system being completely independent. Each independent system has its own RF chain including oscillators, ampli?ers, exciters and receivers which must be considered during calibration. In some sparse arrays, spatial relationship between antennas is not necessarily ?xed. In addition, capturing the radiation patterns of sparse arrays is challenging due to the size of the e?ective array aperture imposing a need for large chambers to reach the far ?eld.This thesis develops an in-situ calibration technique for arbitrarily sparse arrays, a measurement technique in non-ideal semi-anechoic chamber, and validates the experimental results against industry standard electromagnetic modeling and simulation tools