Control systems of a turntable and antenna positioning device in an open area test site

An open area test site (OATS) is a facility to measure radiated emissions of an electrical or electronic equipment in order to comply electromagnetic compatibility (EMC) requirements. In the measurement, the equipment under test (EUT) is placed in a turntable and the electromagnetic field radiated by the EUT is scanned using an antenna attached to a mast. The maximum radiation from the EUT is captured by rotating the turntable and vertically moving the antenna. This paper describes the development of the control systems of the scale models of a turntable and antenna positioning device. Stepper motor and dc motor are used to drive the turntable and antenna positioning device respectively. The motors are controlled by using microcontrollers. Speed and position control systems for both devices have been designed and the accuracies of the systems have been analyzed.