Inductorless amplitude modulator and demodulator apparatus

Claim 2

An inductorless modulator-demodulator circuit for use in combining a pair of input signals, comprising full-wave circuit means including a pair of symmetrical channels each containing a control device (Q2, Q3; Q12, Q13) having at least three electrodes; means (Q4, Q5, Q6; Q14, Q15, Q16) biasing said control devices to Class AB operation; first means (Q1, Q11) for applying to corresponding single electrodes of each of said control devices components of a first input signal, the amplitude of said first signal being such as to produce for each control device a constant specific percent of conduction time (p) per cycle of said first signal; second means (Q6, Q16) for applying simultaneously to corresponding pairs of electrodes of each of said control devices components of a second input signal, said first and second signal applying means being such that the components of one of said input signals are of like phase and the components of the other signal are of opposite phase, respectively; and summation means (R24, R25; R124, R125) for adding the output signals from said control devices at locations at which the resultant output components of one input signal are in phase and the resultant output components of the other input signal are out-of-phase, respectively, thereby to produce an output signal from which said out-of-phase components have been eliminated.

Claim 3

Apparatus as defined in claim 1, wherein said circuit means comprise a full-wave modulator circuit, wherein said first input signal comprises a carrier signal, and wherein said second input signal comprises a modulating signal, whereby said output signal comprises an undistorted amplitude modulated carrier signal containing an unsuppressed carrier.

Claim 4

to maintain substantially constant for each of said control devices the specific percent of conduction time (p) per cycle of carrier signal, thereby to minimize self-induced velocity modulation sensitivity, and

Claim 5

to maintain substantially constant for each of said control devices the specific percent of conduction time (p) per cycle of carrier signal, thereby to minimize self-induced velocity modulation sensitivity, and

Claim 6

to reduce said direct-current components in said channel demodulated signals, respectively.

Claim 7

to reduce said direct-current components in said channel demodulated signals, respectively.

Claim 8

Apparatus as defined in claim 2, and further including second summation means (R22, R23) for adding the output signals from said control devices at locations at which the resultant output components of said one input signal are out of phase and the resultant output components of the other input signal are in phase, respectively, thereby to produce a negative feedback signal, and feedback means (C4, R5) for feeding said feedback signal to said first carrier signal applying means, thereby to elimate rEsidual distortion.

Claim 9

Apparatus as defined in claim 1, wherein said circuit means comprises a full-wave demodulator circuit, wherein said first input signal comprises an amplitude modulated carrier signal, thereby producing at first output terminals of said full-wave circuit carrier envelope, direct-current and carrier harmonic components that are in-phase, and carrier components that are out-of-phase, respectively, whereby an output signal (VOUT) from said demodulator circuit is produced that is the carrier envelope of said amplitude modulated input signal, said circuit including second output terminals at which the carrier signal components are also out-of-phase and the direct-current and carrier harmonic components are also in-phase, respectively; and gain-control means (RAGC1, RAGC2) connected with said second output terminals for feeding back to said second signal applying means a direct-current gain control signal, thereby to cause the gain of the input control devices to correspond with the strength of the amplitude modulated carrier signal and to maintain constant for each control device the percent of conduction time (p).

Claim 10

Apparatus as defined in claim 4, and further including carrier harmonic feedback means (CR) for feeding back to said second signal applying means from said second output terminal means the harmonic components appearing in the output stage of said demodulator circuit means, whereby a smooth resultant carrier envelope signal is produced containing a minimal degree of carrier, direct-current and harmonic components.

Claim 11

Apparatus as defined in claim 1, wherein said control devices have the same polarity, and further wherein said first signal applying means comprise phase-splitter means for supplying to corresponding electrodes of said control devices components of said first input signal that are out-of-phase, respectively.

Claim 12

Apparatus as defined in claim 6, wherein said second signal applying means applied to corresponding pair of electrodes of said control devices components of said second input signal that are in-phase, respectively.

Claim 13

Apparatus as defined in claim 1, wherein said control devices have the opposite polarity, and further wherein said second signal applying means comprise phase-splitter means for supplying simultaneously to corresponding pairs of electrodes of said control devices components of said second input signal that are out-of-phase, respectively.

Claim 14

Apparatus as defined in claim 8, wherein said first signal applying means is operable to supply to corresponding electrodes of said control devices components of said first input signal that are in-phase, respectively.

Claim 15

Inductorless apparatus for amplitude modulating a carrier signal with a modulating signal, comprising a. full-wave modulator circuit means defining a pair of channels for amplitude modulating alternate half cycles of the carrier, respectively, each of said channels including an electronic control device (Q2, Q3) including at least three electrodes; b. means (Q4, Q5, Q6) biasing said control devices, in the absence of a modulating signal, to Class AB operation; c. first means (Q1) for applying components of said carrier signal to corresponding electrodes of said control devices, respectively, said carrier signal being of an amplitude to produce for each control device a specific percent of conduction time (p) per cycle of carrier signal; d. second means (Q6) for applying components of said modulating signal simultaneously to corresponding pairs of electrodes of each of said control devices, respectively, thereby to produce for each of said control devices a resultant amplitude modulated output signal of a magnitude and waveform configuration to maintain constant said specific percent of conduction time for each of said control devices regardless of the instantaneous magnitude of said modulating signal, thereby minimizing croSsover distortion and self induced velocity modulation, one of said first and second signal applying means comprising phase-splitter means for causing the signal components produced thereby to be out-of-phase; e. said pair of channels including a pair of output terminals at which said carrier signals are in phase, said modulating signals and harmonics of said carrier signal are out of phase, and direct-current components are in opposition, respectively; and f. summation means (R24, R25) for algebraically adding the channel output signals appearing at said output terminals to cancel said modulating signals, said carrier signal harmonics, and said direct-current components, thereby to obtain an undistorted amplitude modulated output signal.

Claim 16

Inductorless apparatus for amplitude modulating a carrier signal with a modulating signal, comprising a. full-wave modulator circuit means defining a pair of channels for amplitude modulating alternate half cycles of the carrier, respectively, each of said channels including an electronic control device (Q2, Q3) including at least three electrodes; b. means (Q4, Q5, Q6) biasing said control devices, in the absence of a modulating signal, to Class AB operation; c. first means (Q1) for applying components of said carrier signal to corresponding electrodes of said control devices, respectively, said carrier signal being of an amplitude to produce for each control device a specific percent of conduction time (p) per cycle of carrier signal; d. second means (Q6) for applying components of said modulating signal simultaneously to corresponding pairs of electrodes of each of said control devices, respectively, thereby to produce for each of said control devices a resultant amplitude modulated output signal of a magnitude and waveform configuration to maintain constant said specific percent of conduction time for each of said control devices regardless of the instantaneous magnitude of said modulating signal, thereby minimizing croSsover distortion and self induced velocity modulation, one of said first and second signal applying means comprising phase-splitter means for causing the signal components produced thereby to be out-of-phase; e. said pair of channels including a pair of output terminals at which said carrier signals are in phase, said modulating signals and harmonics of said carrier signal are out of phase, and direct-current components are in opposition, respectively; and f. summation means (R24, R25) for algebraically adding the channel output signals appearing at said output terminals to cancel said modulating signals, said carrier signal harmonics, and said direct-current components, thereby to obtain an undistorted amplitude modulated output signal.

Claim 17

Apparatus as defined in claim 10, and further including negative feedback means (C4, R5) for feeding back to said first signal applying means a control signal that is 180* out of phase with said output signal.

Claim 18

Apparatus as defined in claim 11, and further including means (bias of Q4, Q5) for compensating for intraelectrode capacitance changes of Q2, Q3, respectively, thereby further minimizing self-induced velocity modulation and cross-talk.

Claim 19

Inductorless apparatus for demodulating an amplitude modulated carrier signal to detect the envelope thereof, comprising a. circuit means defining a pair of channels for demodulating alternate half cycles of the carrier signal, respectively, each of said channels including an electronic control device (Q12, Q13) including at least three electrodes; b. first means (Q11) for applying said amplitude modulated carrier signal to corresponding electrodes of said control devices, respectively; c. biasing means (Q14, Q15, Q16) biasing said control devices to Class AB operation relative to the unmodulated component of said amplitude modulated carrier signal, thereby to obtain in said channels, for alternate half cycles of the carrier signal, respectively, demodulated signals (Q12C, Q13C) each including a direct-current component, a carrier signal component, a carrier envelope component, and a plurality of carrier signal harmonic components; d. summation means (R124, R125; R122, R123) for algebraically adding said demodulated signals to cancel said carrier signal components and to add said direct-current, carrier envelope and harmonic components; and e. second means (Q16) for feeding back in out-of-phase relation to corresponding pairs of electrodes of each of said control devices, respectively, the resultant direct-current component from said summation means, thereby

Claim 20

Inductorless apparatus for demodulating an amplitude modulated carrier signal to detect the envelope thereof, comprising a. circuit means defining a pair of channels for demodulating alternate half cycles of the carrier signal, respectively, each of said channels including an electronic control device (Q12, Q13) including at least three electrodes; b. first means (Q11) for applying said amplitude modulated carrier signal to corresponding electrodes of said control devices, respectively; c. biasing means (Q14, Q15, Q16) biasing said control devices to Class AB operation relative to the unmodulated component of said amplitude modulated carrier signal, thereby to obtain in said channels, for alternate half cycles of the carrier signal, respectively, demodulated signals (Q12C, Q13C) each including a direct-current component, a carrier signal component, a carrier envelope component, and a plurality of carrier signal harmonic components; d. summation means (R124, R125; R122, R123) for algebraically adding said demodulated signals to cancel said carrier signal components and to add said direct-current, carrier envelope and harmonic components; and e. second means (Q16) for feeding back in out-of-phase relation to corresponding pairs of electrodes of each of said control devices, respectively, the resultant direct-current component from said summation means, thereby

Claim 21

Apparatus as defined in claim 13, and further including harmonic feed-back means (CR) connected with said second signal applying means for feeding back to said control devices in out-of-phase relation the harmonic components of said carrier signal, thereby to reduce the harmonic components contained in said channel demodulated signals, respectively.

Claim 22

Apparatus as defined in claim 14, and further including means for compensating for changes in intra-electrode capacitance, thereby to minimize velocity modulation sensitivity and crosstalk.