Design Of Security Radar Based On Stepped Frequency

As a new, hidden, adapt to the complex terrain change intrusion detection securityequipment, buried underground leak cable perimeter security equipment has broadapplication in military and civilian security field. The article focuses on theimplementations of a kind of perimeter security hardware system based on theStepping-frequency signal source and the leaked cable. The leaked cable as the systemtransceiver antenna, buried underground or embedded in the wall, generating theinvisible electromagnetic field around, man or other large animals through or near thearea will trigger the alarm and the system will locate the intruder’s location and theorientation. As the electromagnetic can invisible, intruders can not feel the presence ofleakage cable and its location, also there is no way to bypass and undermine.The system consists of six functional modules. There are broadband Stepping-frequency transmitter, Zero-IF receiver, FPGA synthesis control processing unit, USBdata transmission unit, transmitting and receiving antennas, PC application software.Transmitter frequency source part generated1.1GHz~2.1GHz frequency with5MHzstepped by the ADF4350controlled by DDS module. It transmits through the digitallycontrolled attenuator, power amplifier, frequency-selective filter network, and final toconstitute the power controllable Stepped-frequency transmitter. The receiver useAD8347chip as the direct conversion quadrature demodulator. Get baseband datathrough the IQ dual channel sampling and upload the data to a computer via USB2.0interface and save as data files for analyzing the intrusion. The transceiver antenna iscomposed by two spiral slotted coaxial leaked cable buried underground as the invasiondetection sensor. The PC application software interface written using MFC, by callingthe USB driver API function interface, transfer data with the hardware system. Themaster chip of the system is Xilinx Spartan3’s family FPGA, it completes thecoordinated configuration, control and interaction of the various functional modules ofthe entire system.The hardware system integrated various functional modules on a PCB plate,completion the hardware design and debugging of each module. Build experimental test platform, physical test the system witch simulated the invasion scene. The transmitpower is+5dBm, each frequency point to restore stability time is35us and holding timeis200us. The distance between the cables is0.5m, to test intrusion information on pointfrequency and step sweep mode. after testing, the system can correctly detect intrusionsand save the invasion information data.