The Hardware Design Of ARM-based Test System In The Microwave Darkroom

Development of high performance antenna depends on a high-precision test system. Antenna test system is composed of servo system, test equipment and monitoring system. The quality of the servo system and rotating platform directly affect the accuracy of the anechoic chamber antenna test. As a result, the design of the hardware is of great significance. This research is chiefly devoted to describing the design of hardware of an ARM-based test system in the microwave darkroom, including the design of drivers in servo system and motor control section. This test system controls the rotation of the motor through the ARM processor with the aim of recording the antenna test data while adjusting the measured antenna attitude. This system is based on Atmel AT91SAM9G45, which is produced by ShenzhenTianMo technology Co., LTD. The final design of a complete test system can automatically send and receive far field testing system, thus reducing the difficulty of the test antenna. By means of spectrum analyzer, the test system can precisely measure antenna pattern, the beam width, the side lobe width, antenna gain and other parameters, which enjoys many features of small measurement error, strong anti-interference ability and high sensitivity measurements.The innovation of this research is to take full advantage of ARM extensibility while using high-precision rotary encoder. Meanwhile we modified the original kernel of Linux 2.6.24, deleted the MCI, LCD drivers, transplanted some drivers like network port, AD and other drivers. The optimization of PID algorithm increases the stability and accuracy of the motor rotation, and accordingly addresses the problem of alignment in testing process. The automation of the testing process simplified antenna complex test process to some extent, and thus makes it convenient for non-professional personnel to carry out its operation.