Patent ID: 7659851

Claim:
An apparatus for reading an electromagnetic fingerprint associated with a radio frequency certificate of authenticity (RFCOA), wherein the apparatus transmits radio frequency (RF) energy at the RFCOA to create the electromagnetic fingerprint and receives electromagnetic effects back from the RFCOA, the electromagnetic effects representing the electromagnetic fingerprint of the RFCOA, comprising: an array of antenna elements capable of being positioned in a near-field of the RFCOA; each antenna element comprising multiple electrically conductive surfaces wherein two adjacent electrically conductive surfaces comprise different physical lengths and approximately the same resonant frequency as achieved by positions of slits in each of the two adjacent electrically conductive surfaces and by positions of respective vias for each of the two adjacent electrically conductive surfaces for, at least in part, connecting their respective electrically conductive surface to a ground; wherein the vias and slits create a folded and meandered geometry of the conductive surfaces that enables each antenna element to be miniaturized to one-eighth or less of the wavelength of the RF energy used to obtain the electromagnetic fingerprint of the RFCOA; wherein the electromagnetic fingerprint of a RFCOA consists of a set of scattering parameters of deflected RF energy unique to the RFCOA observed over a specific frequency band; and the apparatus further comprising a network analyzer communicatively coupled with each of the antenna elements in the array of antenna elements, wherein the network analyzer evaluates the electromagnetic effects received independently at each antenna element of the array to obtain the electromagnetic fingerprint of the RFCOA.