Abstract: An RF tag is provided to communicate with an interrogating source in which the tag has programmability and flexibility to uplink data to multiple platforms. As such the RF tag functions as a miniature programmable transceiver capable of communicating with a plurality of different platforms each having different waveform characteristics. With well-controlled spectral characteristics due to stored waveforms and the use of specialized direct digital up and down conversion techniques, data rates up to 256 kbps are achievable. The tag is thus capable of converting microwave signals directly to digital inputs, and the transmitter generates microwave signals directly from digital outputs. Flexible digital processing also allows a throughput of 900 BOPS when using field programmable gate arrays.

Abstract: A swept-frequency radar system transmits pulses consisting of swept-frequency subpulses of nonuniform duration separated by short nontransmitting periods during which an array antenna is resteered. The pulses reflected from a target are processed by a method including estimating the target ranges, producing a reference signal at the time at which the pulse reflected from the target is expected to return. The reflected pulse is phase detected by means of the reference pulse to produce phase detected signals which include information relating to the error between the actual range and the estimated range. The phase detected signals are Fourier transformed to produce range error information. The nonuniform subpulse durations reduce the magnitude of range sidelobes.