Bar code interrogation system
Presented is a system and method for reading a microwave readable barcode formed from a pattern of dielectric material. The dielectric pattern creates a strong microwave contrast with the surrounding media selectively resonating with or scattering an interrogating microwave signal. Dielectric bars can be fabricated by inkjet printing, injection, spraying, drawing or any other technique. Barcode information is encoded using different lengths, angles, or positions of dielectric bars. A microwave readable dielectric barcode system includes a barcode fabricated from a dielectric material, a transmitter with an antenna, and a sensor that senses the effect produced by the dielectric barcode on the microwave signal. The dielectric barcode system can use multiple microwave signals that differ in one or more respects, such as polarization or frequency.
1. A remote barcode interrogation system comprising:
a dielectric barcode formed from a plurality of dielectric bars arranged within a substrate, wherein the dielectric bars are arranged in a spatial manner to encode information;
a remote signal transmitter connected to a first antenna so as to reradiate a scattered microwave interrogation signal on the dielectric barcode;
a remote signal receiver connected to an antenna so as to receive a microwave return signal from the dielectric barcode; and
a processor connected to the remote signal receiver and operable to extract the encoded information; and
wherein the dielectric bars comprise a dielectric material having a suspension of a metallic material in a density insufficient to provide conductivity at a microwave frequency of the interrogation signal.
2. The interrogation system of claim 1 , wherein the microwave interrogation signal is scanned through a volume of space by one of rotation of the first antenna, frequency shifting, phase shifting.
3. The interrogation system of claim 1 , wherein the first antenna comprises an antenna array and the microwave interrogation signal is scanned by adjusting an inter-element phasing of the antenna array.
4. The interrogation system of claim 1 , wherein the spatial manner arrangement of the plurality of dielectric bars includes at least one of a variation in length, a variation in width, a variation in relative positioning angle, and a variation of interstitial gaps.
5. The interrogation system of claim 1 , wherein the plurality of dielectric bars are formed from dielectric inks.
6. The interrogation system of claim 5 , wherein the dielectric inks are formed from heavy metals and their salts.
7. The interrogation system of claim 6 , wherein the heavy metals and their salts are selected from the group consisting of BaTiO 3 , NaKNbO 3 , PbZrTiO 3 , and Na x K 1−x NbO 3 .
8. The interrogation system of claim 1 , wherein the receiver is connected to a second antenna.
9. The barcode interrogation system of claim 1 used for animal labeling.
10. The barcode interrogation system of claim 1 wherein the dielectric barcode is beneath the skin layer of an animal.
11. The barcode interrogation system of claim 1 wherein the dielectric barcode is a non-degradable tattoo.
12. The barcode interrogation system of any one of claims 9 - 11 wherein the dielectric barcode is formed by an injection mechanism.