Patent ID: 8508369

Claim:
An RFID tag, comprising: a tag substrate; at least first and second spatially separated antennas formed on the substrate; a memory received by the substrate and storing tag data; processing circuitry; first and second modulation circuitries corresponding to the first and second spatially separated antennas, wherein the processing circuitry and first and second modulation circuitries are received by the substrate and coupled among the first and second antennas and the memory, wherein the processing circuitry and first and second modulation circuitries are configured to: receive the tag data; and generate a protocol communication based on the tag data, wherein the protocol communication indicates that the RFID tag is configured to use space-time block coding (STBC), produce first and second blocks of related output symbols, wherein the first block of output symbols includes at least a first pair of symbols and, the second block of output symbols includes at least a second pair of symbols, and wherein at least some of the symbols in the second block of output symbols is a negation and/or complex conjugate of a related symbol in the first block of output symbols; and wherein the first antenna transmits the first block of symbols, and the second antenna transmits the second block of symbols.