Information Involved Emittedelectromagnetic Waves Capturing Andsearch Positioning System Based On Cellphone

Along with the high-speed development of the information society, TEMPEST has attracted the attention and actively exploration at home and abroad. The main problem to be solved of this hot-spot is to intercept the leaked electromagnetic waves contains information as well as to search and orient the intentionally emitted electromagnetic waves. Leakage of information capture and reconstruction and positioning technology is the main content of the research of TEMPEST. Now, the intellectualization of mobile communication terminal makes it possible that mobile phones enter the field of portable electronic detection equipment, while the realization of triple play and4G mobile communications especially expand the functions of the mobile communication terminal or mobile phone functions. Therefore, this thesis studied the detection technology of signal of emitted electromagnetic waves based on the principle of FM radio reception, and designed and implemented an information involved emitted electromagnetic waves capturing and search positioning system based on smart phones.This thesis started by the study of the software and hardware platforms and the working principle of the components of mobile phones. Then this thesis studied the working principle of radios, especially the reception principle of the mobile phone built-in FM module. Meanwhile, to improve the reception performance of the antenna system, this thesis researched the working principle of Dipole antenna and Resonant antenna, and selected Resonant antenna to make up the external antenna system. According to the above findings, this thesis designed a capturing and search positioning system of information involved emitted electromagnetic waves based on an Android smart phone, which researched the designand realization of the capturing and orientation of electromagnetic wavesemitted by FM radios of multiple frequency as an example. At last, this thesis tested the performance of the capturing and search positioning system in the realistic scenarios, and result was given in three different frequency. The test result showed that this capturing and research positioning system was able to real-time capture and analyze the signal of electromagnetic waves emitted by FM radio more accurately with a more superior reception performance and user experience.