Design of anechoic chamber instrumentation and data acquisition module for testing and analysis of the CTHA.

摘要

The backbone of wireless communication is an antenna, a device that converts electromagnetic energy to electric energy and vice versa, to transmit and receive the signals. The effectiveness of a communication system depends largely on the effectiveness of the antenna used in them. The effectiveness of an antenna is characterized by its electromagnetic field. Methods to characterize the field of an antenna include testing them on outdoor test ranges or in enclosures insulated against electromagnetic radiation, called anechoic chambers. The objective of this work is to design and build an automated data acquisition system to map the field of physically small antennas such as a Contrawound Toroidal Helical Antenna (CTHA), placed inside an anechoic chamber built and maintained by the Center for Industrial Research Applications (CIRA), West Virginia University. Two antennas, a dipole in the transmitting mode and the CTHA, the antenna under test, in the receiving mode are used in the tests. The automated setup includes a rotator for mounting the antenna, a signal generator and a spectrum analyzer to analyze the signals from the receiving antenna. The rotator, signal generator and the spectrum analyzer are controlled remotely by a Visual Basic program running on a central control computer. The acquired data is presented in a graphical form, representing the field around the antenna.