Modulators – Amplitude modulator – Nonlinear device controlled by modulating signal
Patent
1985-04-17
1986-12-09
LaRoche, Eugene R.
Modulators
Amplitude modulator
Nonlinear device controlled by modulating signal
332 16R, 332 31R, 455110, H03C 300
Patent
active
046282866
ABSTRACT:
An MSK modulator includes a source of digital sawtooth signals having a recurrence rate equal to the desired recurrence rate of the unmodulated carrier. The digital sawtooth signal is applied to an adder together with a phase control digital signal. The phase control digital signal phase-shifts the digital sawtooth signal. The phase-shifted digital sawtooth signal is applied to a sine ROM to produce a digital sinusoid with an unmodulated recurrence rate equal to the recurrent rate of the digital sawtooth signal. When the phase control signal is an accumulated signal, the digital sinusoid is frequency-modulated. The phase control signal for MSK modulation is a ramp signal generated by a controlled accumulator. The accumulator includes a controllable clocked adder/subtractor, the output of which is coupled by way of a register back to an input. The other input of the adder/subtractor is coupled to receive a fixed ramp rate controlling word. At each clock cycle, the accumulator adds (subtracts) the ramp rate word from the sum under the control of the MARK (SPACE) information content of the information signal to form a two-frequency MSK modulation. More general frequency modulation is accomplished by an accumulator with an input word which responds to the instantaneous amplitude of the information signal. A clocked delay and a subtractor indicate the direction of frequency deviation.
REFERENCES:
patent: 3170127 (1965-02-01), Cramer
patent: 3689914 (1972-09-01), Butler
patent: 3987374 (1976-10-01), Jones
patent: 4170764 (1979-10-01), Salz et al.
patent: 4206424 (1980-06-01), Nossen
patent: 4206425 (1980-06-01), Nossen
patent: 4331941 (1982-05-01), Kovalick et al.
patent: 4355289 (1982-10-01), Beyer et al.
patent: 4484296 (1984-11-01), Treise et al.
patent: 4562414 (1985-12-01), Linder et al.
patent: 4584541 (1986-04-01), Nossen
LaRoche Eugene R.
Meise William H.
Pascal Robert J.
RCA Corporation
Tripoli Joseph S.
LandOfFree
Digital frequency modulator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digital frequency modulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital frequency modulator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1387463