Envelope rate demodulator

Claim 2

An envelope rate demodulator for extracting the time rate of change of the envelope of an amplitude modulated waveform, comprising: a. sampling means for sampling said amplitude modulated waveforms, each sample including an integral number of cycles, commencing at a zero crossover region, of the waveform''s high frequency component, b. integrating means for generating electrical quantities that are proportional to the integrated valuEs of said samples and provide a measure of the average time rate of change of the corresponding envelope segments, c. output means, and d. buffer means for sequentially applying said electrical quantities to said output means.

Claim 3

An envelope rate demodulator as in claim 1 wherein said sampling means comprises: a. first switching means for selectively applying the amplitude modulated waveform to said integrating means during sample periods, b. second switching means for selectively coupling said integrating means to said buffer means during holding periods which follow said sample periods, c. a discharge network, and d. third switching means for selectively coupling said integrating means to said discharge network at the termination of said holding periods so as to ready said integrating means for subsequent samples.

Claim 4

An envelope demodulator as in claim 2 wherein: a. said integrating means comprises first and second integrating networks, b. said first switching means includes a first switching device coupled to said first integrating network and a second switching device coupled to said second integrating network, c. said second switching means includes a third switching device coupling said first integrating network to said buffer means and a fourth switching device coupling said second integrating network to said buffer means, and d. said third switching means including a first pair of switching devices coupling said first integrating network to said discharge network and a second pair of switching devices coupling said second integrating network to said discharge network, said first device, first pair of devices and third device being operated in a first time sequence, and said second device, second pair of devices and fourth device being operated in a second time sequence out of phase with said first sequence so that said first and second integrating networks provide an alternate integration of said samples.

Claim 5

An envelope demodulator as in claim 3 which includes a source of timing signals and means for applying said timing signals to said switching devices.

Claim 6

An envelope demodulator as in claim 4 wherein said first and second integrating network, discharge network and buffer means are each in the form of an operational amplifier.