Two-frequency surveillance technique for intrusion-detection sensor with Leaky Coaxial Cables

This paper presents a new design and achievement of Leaky Coaxial Cable (LCX)-based intrusion-sensing techniques. LCX radiates microwaves from slots milled on the outer conductor. This sensor can detect an intrusion object by measuring the variation of received signal. LCX has two types of emitting modes, radiation mode and surface mode. The microwave radiates to far field in radiation mode. On the other hand, the microwave exists only around the LCX in surface mode. Although the conventional LCX-based sensor operates the LCX in only one mode to detect and classify an object, this paper introduces a simultaneous sensing technique using these two modes. Comparing the signals in both modes, the classification of an object can be estimated. The theory of the emitting modes of LCX and the developed sensor prototype are described. Experimental results are presented to show that the proposed sensing techniques are valid.