초록 ▼

An intrusion detection system includes a transmitter of wave energy at one end of a transmission line or coaxial cable, for example, and a receiver connected directly to the transmission line or a cable at the other end together with a series or discrete antennas uniformly spaced along the transmiss

An intrusion detection system includes a transmitter of wave energy at one end of a transmission line or coaxial cable, for example, and a receiver connected directly to the transmission line or a cable at the other end together with a series or discrete antennas uniformly spaced along the transmission line and relatively loosely coupled thereto. The coupling between the antennas and the transmission line or coaxial cable is determined to be of an optimum value and in such a system the sensitivity to an intrusion is the same along the length of the coaxial cable or transmission line for the same distance from the transmission line.

대표청구항 ▼

A perimeter intrusion detection system comprising a transmitter for generating a wave signal to be propagated, an elongated wave propagating element connected at one end to said transmitter and defining at least a portion of the intrusion perimeter, said wave propagating element including means for

A perimeter intrusion detection system comprising a transmitter for generating a wave signal to be propagated, an elongated wave propagating element connected at one end to said transmitter and defining at least a portion of the intrusion perimeter, said wave propagating element including means for radiating energy relative to said intrusion perimeter and for receiving radiated energy from said intrusion perimeter, and a receiver connected at the other end to the wave propagating element.