Design And Realization Of CDMA Terminals Parallel RF Calibration System

In order to meet standard requirement at RF performance, Every CDMA terminal must be RF calibrated during being produced. The measurement instruments which are used to produce the communications products are very expensive, so it will need a large of money when the production lines expand. This is a very big burden for the corporation. This paper offers a low cost and high efficiency solution of CDMA terminals Parallel RF calibration system. The solution can get more output of product line with less money.This paper introduced the principle and method of RF calibration firstly, based on the analysis of the RF calibration systems used normally in most factories now, and proposes a kind of low cost and high efficiency Parallel RF calibration system. This system is an automatic test system based on GPIB technology. In the hardware design aspect, in order to realize the goal which simultaneously calibrates two CDMA terminals, we design a special-purpose RF interface box, and use a simple method to realize the RF path switch between the two terminals and two instruments, and build the whole system. In the software design aspect, we select Visual C++6.0 as programming language, use Layered structure design concept to carry on the software design. The UI design is very Simple and clear, and very easy to use for the operators. The software design Use the event synchronization mechanism to solve instrument resources robbing of the double thread. The function of every layer and how to design were presented, the main flowchart and sub flowchart of RF calibration are given out, and the calibration methods how to improve efficiency of RF calibration were proposed. Then, through comparing and analyzing the calibration results and test the terminals RF performance after RF calibration, testify the system adjusting results is very accurate, reliable and repeatable. Through the analysis of the test used time, testify this system can increase the output approaching 100%. Finally, a RF loss measurement system was worked out for system maintenance to meet requirements of reality application.The Parallel RF calibration system satisfied the requirement of the output expansion of communications terminals manufacturers. Because of using general instruments as test equipments, the hardware of system is still available in production in the coming 3G times.