The Precision Radio Instrument for Antenna Measurements

Author: ORCID icon
Makhija, Krishna, Electrical Engineering - School of Engineering and Applied Science, University of Virginia
Bradley, Richard, Electrical Engineering, University of Virginia

Antennas used in areas like mobile tower communications, defense, and astronomy oftentimes need to be measured in-situ to calibrate real-world effects like the environment and multipath scattering. While anechoic chambers are adequate for most applications, larger antennas used in radio astronomy, radars, and on mobile towers need new techniques for in-situ characterization. Large elements consisting of reflector and feed combinations have farfield distances high enough to limit the use of outdoor antenna ranges as well. In addition, most anechoic chambers and even outdoor ranges do not support frequencies below a few hundred MHz. There is thus a need for alternate antenna beam mapping techniques.

One novel method for in-situ beam measurements is utilizing an aerial platform like a multirotor drone mounted with a radio source. The Precision Radio Instrument for Antenna Measurements (PRIAM) is a first-generation drone-based antenna calibrator custom-built for this purpose. It utilizes commercial off-the-shelf drone components, software-defined radio, and single-board computers like Raspberry Pi to form an autonomous calibration system capable of high-accuracy magnitude measurements. In this dissertation, I present its design and some initial results. In addition, this dissertation also contains some experiments and a feasibility study of using PRIAM to perform phase measurements of the antenna beam using a novel technique.

PHD (Doctor of Philosophy)
radio astronomy, software defined radio, phase measurements, precision timing, priam, antenna measurements, atomic clocks, calibration, beam mapping, beam patterns, drones, uav, low frequency, 21-cm cosmology
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