Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Digital FSK demodulator










Image Number 2 for United States Patent #4485347.

The disclosed FSK demodulator includes a digital PLL for converting an FSK modulated input signal with two different frequencies to rectangular waveforms having durations as determined by those frequencies, two reversible N bit counters for counting clock pulses to determine instantaneous duty factors in the form of N parallel bits of the waveforms for each pulse repetition period, and a read only memory for multiplying alternate outputs, except for the sign bit, from the counters by a ratio of the lower to the higher frequency of the input signal. Then, a digital first-order low-pass filter removes a high frequency component from the output of the read only memory, resulting in a demodulated binary signal. The binary signal may be produced by setting or resetting a FLIP-FLOP when the sign bit from each of the counters is respectively a binary ONE or ZERO. Alternatively, another reversible M bit counter (when M>N) may count the clock pulses to equal the output from the read only memory.








 
 
  Recently Added Patents
Method and system for quantifying viewer awareness of advertising images in a video source
Single mode optical fiber with improved bend performance
Apparatus and method for adapted deblocking filtering strength
Information processing apparatus, non-transitory computer-readable recording medium, and information processing method
Array substrate including thin film transistor and method of fabricating the same
Systems and methods to provide communication history for communication devices
Insulin derivative
  Randomly Featured Patents
Decorative surface of a tire sidewall
Finger-actuated slideable-gate dispensing valve
Cupholder for mounting on basket of shopping cart
Supported metal oxide catalysts for the simultaneous removal of NO.sub.x and SO.sub.x from gas streams
Method and system for checking the introduction of a filler pipe into a tank
Method a group of picture structure in MPEG video
Method for manufacturing sleeved garments
Radio communication system
Apparatus and method for manufacturing a semiconductor package
Conveying system for conveying substantially cylindrical objects such as nuclear fuel pellets