Automatic test system of the antenna characteristic

The antenna is a component used to transmit or receive electric waves in a wireless communicating system. At the transmitting terminal its primary function is to change electrical current of high frequency transmitted by transmitter or, transmission line into a wireless wave and transmit it into space; at the receiving terminal it changes the energy of the wireless wave into electrical current. Then, we can regard antenna as transforming equipment between conducting waves and radiate waves. The antenna has an important influence on the normal working of wireless communication, broadcasting, orientation and telemetry system. The antenna has influence on EMC just as important as that which it has on communication. In EMC emission measurements, EMI testing and EMS testing included; the antenna acts as the receiving component and the transmitting component separately. The antenna is the important equipment that receives the energy of radiation and it also is the important equipment that sends electromagnetic signals to the object that being tested. Thus, if there is no antenna, we cannot go on with our EMC testing. Any antenna has some characteristic parameters, which can be used to estimate this antenna´s performance. These characteristic parameters include antenna impedance, directional property, antenna gain, posture, and the polarization characteristic, which determine that an antenna is fine and the area that it can be used in. So, these characteristic parameters have a great influence on the measuring result and the area it is used in. As every worker of EMC testing knows, it is very difficult to measure an antenna´s characteristic parameters, some of which are not even measured by the current method. Some people try to measure them, but it takes much time and labor testing with conventional testing methods (i.e. testing by hand). What´s more, it is easy to introduce testing errors. With the development of computers and the emergence of advanced testing equipment, it is necessary and possible to design a convenient automatic testing system for the antenna performance.