Patent ID: 7825774

Claim:
A radio frequency communications device comprising: a transmitter and a receiver, the transmitter selectively transmitting a signal using a modulation scheme to an interrogator in response to receiving an interrogation request from the interrogator using a modulation scheme, the transmitter being capable of transmitting using at least three different modulation schemes selected from the group consisting of Frequency Shift Keying (FSK), Binary Phase Shift Keying (BPSK), On-Off Keying (OOK), and Amplitude Modulation (AM), and being switchable to select one of the modulation schemes, wherein, for the selected modulation scheme, a carrier for the transmitter is generated by an integrated circuit, in an active mode, the integrated circuit further being switchable to transmit in a modulated backscatter mode in which the integrated circuit uses a carrier transmitted by the interrogator, wherein the transmitter is configured to switch between the active mode and the backscatter mode in response to a radio frequency (RF) command.