A radio frequency (RF) data carrier and method and system for reading information
stored in the data carrier are presented. The data carrier comprises a collection
of circuitries defining together a predetermined information code. Each circuitry
includes: (a) a code circuit configured to have a certain RF frequency response
to a powering signal and thus defining a certain symbol of the predetermined information
code, and (b) a delay circuit configured to provide a phase delay of a predetermined
value to said powering signal associated with the respective code circuit to thereby
define a location of this symbol in the information code. The data carrier further
comprises a power unit operable to produce said powering signal to actuate the
delay circuit. The power unit comprises at least one inductance coil responsive
to alternation of an external magnetic field for generating said powering signal
as an electromotive force voltage as a result of intersecting windings of the coil
with magnetic flux lines of the external magnetic field.
