A design of precision linear z-transverse antenna positioner

Abstract

An antenna positioner is essential device in avionics as a testing instrument. It must be able to move the antenna under test (AUT) to the required position precisely and accurately. This research focuses on the design of precision linear z-traverse antenna positioner. It comprises designs of mechanical, electrical and control system. Besides, knowledge on software design is also of paramount important because the designed instrument run by own developed control algorithm. It is a positioner powered by a DC motor as an actuator which is equipped by a user friendly graphical user interface (GUI) written uniquely featured with several distinct and systematic operating modes and flexible data display. PID (Proportional, Integral and Derivative) controller embedded in GUI is also capable to move AUT to the target in shortest time with no or minimum overshoot and steady state error. In this research, PID controller was tuned to suit the application with the aid of MATLAB® simulation. The system was then calibrated. Based on calibrated data, it was then optimized to yield more accurate result by mean of correction through software compensation. The result was then analyzed and discussed. A very precise instrument with standard deviation m µ s 94 . 8 = was successfully designed. It was designed to be used in two ways with accuracy of approximately m µ 50 ± or 29ppm for high accuracy usage and approximately m µ 300 ± or 176ppm for lower accuracy usage. As a consequence, procedures of design and developing a positioner both theoretically and practically were acquired.