×

FSK or am modulator with digital waveform shaping

  • US 4,871,987 A
  • Filed: 03/28/1988
  • Issued: 10/03/1989
  • Est. Priority Date: 03/28/1987
  • Status: Expired due to Term
First Claim
Patent Images

1. An FSK modulator for a mark-space signal comprising:

  • first sequence generating means responsive to the beginning and end time points of each of the marks in the mark-space signal for generating a first sequence of digital values at every predetermined period, the magnitudes of the digital values in the rising and decaying intervals of the predetermined period being respectively defined as specific functions stored in said generating means and the magnitude of the digital values in the intermediate interval being constant;

    second sequence producing means for producing out of the first sequence of digital values a second sequence of digital values the magnitudes of which represent a sinusoidal wave, the instantaneous frequency of the sinusoidal wave corresponding to the magnitude of each of the digital values of the first sequence; and

    converting means for digital-analog converting the second sequence of digital values into an analog signal of said sinusoidal wave to form an FSK signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×