Acoustic Transponder Receiver Circuit.
Patent, Filed 7 Dec 88, patented 16 Apr 91,
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
A transponder that responds differently to two different input signals. The first input signal is at a first frequency. The first input signal is detected by a first powered detector that operates at the first frequency. The transponder responses in a first mode to the first input signal. The second input signal consists of short pulses at the first frequency and at a second frequency. The transponder responds to short pulses at the first frequency by powering a second detector. The first and second detector then detect the second input signal. The transponder responds in a second mode to the second input signal. Author