Ru Bee - How RuBee Works

How RuBee Works

IEEE 1902.1 RuBee uses magnetic waves also often called inductive communication. James Clerk Maxwell presented his now famous set of equations (Maxwell's Equations) to the Royal Society in 1864. These equations describe what happens when an electron travels along a conductive wire. Two fields are created, the Electric Field, labeled E, and the Magnetic Field, labeled H. These electric and magnetic fields travel through the aether, (i.e. outer space or the far field), at the speed of light with an assumed impedance of 377 Ω. E, the electric field, may be given in newtons per coulomb or volts per meter, and H, the magnetic field, may be given in gauss or amperes per meter. The two fields are tied together with the aether to form simple electric circuit capable of transferring power. However, when these two fields are measured in what is called the near field (much less than the wavelength of the signal) very strange things happen. (Also see Capps “Near Field or Far Field"). E and H are no longer connected in a simple predictable manner. The value of c (speed of light) and the resistance of the aether are altered and it is possible to produce large H values with low E values. It is as if the aether impedance has been reduced to only a few ohms.

Virtually all of the energy radiated by a RuBee base station or a RuBee radio tag is contained in the magnetic field (H), not the electric (E) field. This stems from the fact that the RuBee antennas are short relative to the wavelength (about a mile and half or 2½ km at 131 kHz), and RuBee operates in the near field. A typical emitted E from a RuBee base station is about 40-50 nanowatts, and H is about 900 milligauss (90 µT). Finally, RuBee is a packet based protocol in which only one end of the communication at a time generates fields, that is, a RuBee tag is a radiating transceiver.