Intrusion detection system

An intrusion detection system comprising:

• a transceiver including a source of r.f. energy, a receiver and signal processing means for extracting information from any received r.f. signal;
• a single coaxial cable coupled to said transceiver to conduct r.f. energy from the source and transfer r.f. energy to the receiver;
• and
• at least one coupled wave device positioned on the cable and adapted to locally transfer r.f. energy between a transmission mode within the cable and a guided mode along the exterior of the cable.

An intrusion detection system comprising:

• a transceiver including a source of r.f. energy, a receiver and signal processing means for extracting information from any received r.f. signal;
• a first coaxial cable coupled to said transceiver to be energized thereby;
• a second coaxial cable coupled to said transceiver to transfer any received r.f. signal thereto;
• and
• at least one coupled wave device positioned on each cable, each coupled wave device adapted to locally transfer r.f. energy between a transmission mode within the cable and a guided mode along the exterior of the cable.

An intrusion detection system comprising:

• a transmitter providing a source of r.f. energy connected to one end of a first coaxial cable;
• a second coaxial cable located adjacent the first cable and spaced therefrom;
• a receiver connected to an end of the second cable remote from the end adjacent to the transmitter;
• and
• at least one coupled wave device positioned on each cable, each being adapted to locally transfer r.f. energy between a transmission mode within the cable and a guided mode along the exterior of the cable.

An intrusion detection system comprising:

• a transceiver including a source of r.f. energy, a receiver and signal processing means for extracting information from any received r.f. signal;
• a first coaxial cable coupled to said transceiver to be energized thereby;
• a parallel leaky coaxial cable coupled to said transceiver to transfer any received r.f. signal thereto;
• and
• at least one coupled wave device positioned on said first cable and adapted to locally transfer r.f. energy between a transmission mode within the cable and a guided mode along the exterior of the cable, whereby the first and second cables define an intruder detection zone.

An intrusion detection system comprising:

• a transceiver including a source of r.f. energy, a receiver and signal processing means for extracting information from any received r.f. signal;
• a coaxial cable coupled to said transceiver to be energized thereby;
• at least one coupled wave device positioned on said cable and adapted to transfer r.f. energy between a transmission mode within the cable and a guided mode along the exterior of the cable;
• and
• an antenna coupled to said transceiver, whereby the cable defines an intruder detection perimeter.

An intrusion detection system comprising:

• a conductor spaced from ground and extending between a pair of coupled wave devices;
• a transmitter including a source of r.f. energy;
• a first shielded line connecting said transmitter to one of said coupled wave devices;
• a receiver including signal processing means;
• and
• a second shielded line connecting the other of said coupled wave devices to said receiver;
• whereby targets in the vicinity of said conductor alter the coupling between said coupled wave devices and the alteration is detected by said signal processing means.

A method of intrusion detection using a conductor extending around a perimeter comprising the steps of:

• positioning coupled wave devices at spaced intervals on said conductor;
• supplying r.f. energy to one of said coupled wave devices whereby guided waves are launched to travel along the exterior of the conductor;
• and
• connecting another of said coupled wave devices to a receiver whereby alterations in the energy received from said guided wave indicate the presence of an intruder.