Development of a Phased Array Feeds Prototype Using a Uniform Linear Array Antenna for Direction of Arrival Estimation Applications

This study investigates the implementation and performance of a Phased Array Feeds (PAF) prototype for Direction of Arrival (DoA) estimation in radio astronomy. Utilizing an eight-planar Vivaldi antenna to performs a uniform linear array (ULA) to receive signals from multiple directions that has an operating frequency at 1420 MHz for hydrogen line observation. The analog signals are converted to digital via high-speed ADCs and processed using an FPGA. Two DoA estimation algorithms, Conventional Beam Forming (CFB) and Multiple Signal Classification (MUSIC), were evaluated. Despite challenges with frequency mismatches in the balun and field-test environment, phase calibration improved the DoA estimation accuracy. The experimental setup included five positions for a source generator to facilitate data collection. The study demonstrates the prototype's capability to generate a DoA spectrum, offering aspects of its accuracy and performance, which is crucial for enhancing radio astronomy observations.