The Design Of PCB Level EMC Automatic Measurement System

With the rapid development of high speed integrated circuit technique and computertechnique, the electronic products are not only widely used in different areas but also withpowerful function and abundant variety. At the same time the system complexity increasesand so is the interference between different components and systems. Hence, the productreliability has received extensive attention in industry.Since the PCB layout is basic carrier which integrates various functional modules toform the core part of electronic products, the fast assessment of electro-magneticinterference problem on PCB layout is an effective way to shorten the design period andimprove reliability of electronic products. This paper, based on this background, presents aPCB level EMC Automatic Measurement System which can be used to find out EMCinterference source fastly, intuitively and precisely and provide electronic design engineera low cost and fast testing method.The PCB level EMC Automatic Measurement System is composed of three partswhich are2D movement arms, program control computer and remote control spectrumanalyzer. In this system the program control computer is the core which makes the2Dmovement arms and spectrum analyzer work cooperatively to complete the scanning ofPCB layout by using the designed probe antenna. The interference signal of scanned pointsis sent to spectrum analyzer and then the program control computer reads the data fromspectrum analyzer and stores data for after-stage data processing. Then the Design of PCBlevel EMCAutomatic Measurement System is completed.The automatic system generally consists of three parts: the design of2D movementarms and circuit control board design, magnetic probe antenna design and upper computerinterface program design. The first part introduces the design of2D movement arms and the design of circuit control board. The second part introduces the design of magneticprobe antenna design. In this part some related theory of antenna design is introduced firstand then the antenna model in HFSS is given out with simulated results. At last thisantenna is fabricated and measured and the measured result is given. The third introducesthe design of upper computer interface program. It mainly includes the2D movement armscontrol program, the remote control of spectrum analyzer and data acquisition andafter-stage data processing. Finally the debugging and testing of whole system iscompleted. The result shows that this system can conveniently and effectively diagnosePCB level EMC interference. This design lays a good foundation for application of suchdetection device.