Patent ID: 6791489
Filing Date: 2004-09-14
Classification: G01S

Abstract:
A tag apparatus, capable of detecting, decoding and validating a radar message contained in an AM and FM signal component of a received LFM (linear frequency modulation) pulse waveform from a radar source, and encoding and retransmitting, back to the radar source, a tag message contained in a PM and FM signal component of a modified LFM pulse waveform, the apparatus comprising:a) an antenna input circuit for receiving the LFM pulse waveform having digital information; b) an AM/FM signal component validation circuit, in electrical communication with said antenna, for detecting, decoding and validating said AM and FM components in the LFM waveform, and comparing the components to a predetermined criteria, in electrical communication with said antenna; c) a delay element in electrical communication with the antenna for storing the received LFM pulse waveform; d) a chopped repeater circuit, in electrical connection with the delay element for encoding the stored LFM pulse waveform in the delay element with a preprogrammed AM and a FM predetermined criteria to form a modified LFM pulse waveform; e) timing synchronization circuitry for synchronizing the chopped repeater circuit of the modified LFM pulse waveform with reception of the received LFM pulse; and f) an antenna output circuit, in electrical communication with the chopped repeater circuit, retransmitting of the modified LFM pulse back to the radar source.