Abstract: A voltage and a data signal superimposed on the voltage are input to the drain of an FET and a carrier signal is input to the gate of the FET. The FET mixes the data signal and the carrier signal to generate the mixed signal. Two capacitors are connected between the source and ground for blocking direct current and passing alternating current.

Abstract: This contribution involves the generation, transmission, propagation and selective reception of electrical, magnetic or electromagnetic energy in the form of a halfwave sinusoidal pulse signal, from one location to another, whereby intelligence input for transmission is recovered from one sinusoidal pulse, or from a plurality of sinusoidal pulses. In a transmitter embodiment, one or more sinusoidal halfwave pulse generators are provided, where each pulse signal may be generated asynchronously, with varying polarity, duration and amplitude on a continuous serial sampled information basis. Complementary pulse signal filtering and recovering of transmitted intelligence is provided in a signal receiver embodiment. Another transmitter embodiment includes a software-driven signal synthesizing capability, wherein a plurality of timed sinusoidal halfways pulses are linearly summed as elementary signal components of an information-carrying propagable signal.

Abstract: A high frequency pulse-time modulation signal generator employs first and second microwave or laser oscillators which are mutually locked uniquely either in a symmetric mode or an antisymmetric mode by means of an electronic phase shifter. The output signals from the oscillators are combined to generate pulse-time modulated output pulses through application of a control voltage to the electronic phase shifter which switches the mutual locking of the oscillators back and forth between the symmetric and antisymmetric modes. In a microwave embodiment, a hybrid-tee, such as a magic-tee, is employed to combine the oscillator output signals, while in the optical or laser embodiment, a half-silvered mirror is employed to combine the oscillator output signals. When the oscillators are locked in the symmetric mode, the hybrid-tee generates an output pulse, and when the oscillators are locked in the antisymmetric mode, the hybrid-tee generates a zero level output.

Abstract: A carrier frequency modulating system and method for producing a modulated carrier frequency is disclosed. The system comprises a carrier frequency signal generator for producing a carrier frequency signal at a carrier frequency at an output thereof. The system further comprises a sequencer for producing a modulation signal at an output thereof. This modulation signal comprises a plurality of modulation signal portions separated by at least one null modulation signal portion having a corresponding time length. The system is provided with a modulator for producing a modulated carrier frequency signal at an output thereof. The modulator has a first input connected to the output of the carrier frequency signal generator for receiving the carrier frequency signal, and has a second input for receiving the modulation signal. The system further comprises a power supply unit for supplying electrical power to the carrier frequency signal generator.

Abstract: A pulse step modulator (PSM) is presented herein for use in an AM transmitter. The modulator includes a plurality of unit step modules each including a DC voltage source and an associated actuatable switch for, when actuated, turning on the associated module to provide a unit step voltage. An output circuit is connected to the modules for providing an output voltage to a load wherein the magnitude of the output voltage is equal to the sum of all of the voltage sources of the modules that are turned on. An addressable memory is provided which has a plurality of addressable storage locations with each storing and providing, when addressed, a pattern of control signals respectively associated with the modules with each control signal being a turn on signal or a turn off signal for controlling the turn on or turn off of an associated module. The memory is addressed with an address which has a turn on portion and a start point portion.

Abstract: An improved pulse step modulator (PSM) is presented herein for use in an AM transmitter. The modulator includes a plurality of unit step modules connected together in series with each module including a DC voltage source together with an associated actuatable switch for, when actuated, turning on the associated module to provide a unit step voltage. An output circuit is connected to the series connected modules for providing an output voltage to a load wherein the magnitude of the output voltage is equal to the sum of all of the voltage sources of the modules that are turned on. A plurality of module turn on signals are provided with each turn on signal serving to actuate one of the switches in one of the modules with the number of turn on signals being provided being dependent upon the magnitude of the input signal. The turn on signals are provided by circuitry including an addressable memory and addressing means.

Abstract: A digital communication system using a frequency-independent, high data transmission rate, self-clocking, d.c. balanced data encoding technique. The encoding technique converts two NRZ data bits into a pulse or pulse-pair. The form of the pulse or pulse-pair representing the encoded data bit-pair depends upon the average d.c. level of the previously transmitted pulses. Each pulse of a pulse-pair has a fixed width. The receiver is activated by the leading edge of a transmitted pulse-pair and samples the pulse-pair at points in time determined by the known fixed width of the pulses. The sampled pulse-pairs are then converted into NRZ data bit-pairs. Proper functioning of the receiver does not rely upon the rate upon which the data is transferred. A high data rate is achieved by encoding two bits of data in every pulse or pulse-pair transmitted.

Abstract: A narrow band complex input signal, typically having multiple independently modulated carriers, is processed to produce an output signal which, while containing the information in the input signal, is not an amplitude dependent signal, and thus can be transmitted through nonlinear media, such as a saturated power amplifier, as a less expensive and more power-efficient alternative over a conventionally required linear power amplifier. The process separates the multiple input signals into an amplitude-limited angle-modulated carrier component and an envelope component, and then combines these components by a form of pulse-duty-factor modulation such as pulse-duration modulation, at a sufficiently high sampling rate. The combined signal is input to a nonlinear power amplifier. Unwanted sidebands are rejected by bandpass filtering at the amplifier output so as to pass only the carrier and its signal bandwidth.

Abstract: A PWM circuit of programmable subframe system includes a control circuit 20 for generating control signals Cm-CO according to the number of subframes, a PWM data register 60 for storing PWM data, a comparison/correction circuit 40 for determining the sequence of connections of the counter and then comparing the value of a counter 30 with the value of the register 60 to generator overflows under the control of the control signals and also simultaneously generate correction signals, a counter 30 for determining the seqence of connections by the circuit 40 and counting-up to return th e overflows to the circuit 40, a CMP OR Gate 70 for OR operating the correction signals generated in the circuit 40, a modulator 50 for setting and resetting the output and giving correction output.

Abstract: Analog measured values are processed by an A/D converter (50) and/or digital measured values are processed by a timer (60) in a microcomputer and fed through a P/S converter (62) to a logic means (42). Furthermore, RF pulses are fed by an oscillator means (44) to an additional input of the logic means (42). The logic means (42) transfers the RF pulses of the oscillator means (44) to a transmitter (4) for wireless transmission of measured values whenever the P/S converter (62) feeds pulses to another input of the logic, the length and spacing apart of such pulses depending on the measured values.

Abstract: A switching modulator for a microwave radar transmitter is presented. In embodiment, a string of series connected transistors is controlled from an external source for pulse modulating the cathodes of transmitter microwave tubes. The individual components of the series string can be individually switched ON or OFF in order to maintain regulation of the modulation pulse. In a second embodiment, a pulse transformer has a plurality of individual primary windings and a single secondary winding wherein the primary windings are specially wound to provide isolation between the primary windings with the flux in the secondary winding and the voltage generated in the secondary winding being proportional to the sum of the excitation of the primary windings. Each of the primary windings are individually switchable for regulating the generated output voltage at the secondary winding.

Abstract: A differential delta-sigma modulator of switched-capacitance type is operated with a three-phase cycle, rather than the two-phase cycle of the prior art. In the first phase of operation the switched capacitors are charged in accordance with the previous single-bit output of the modulator. Structural modifications permit the switching capacitors to be connected in series to receive the modulator input voltage during the second phase of operation so that voltage need not be balanced with regard to any specified common-mode potential. In the third phase of operation the switched capacitors discharge from first plates thereof to the differential-input integrator while the second plates thereof are driven in accordance with the previous single-bit output of the modulator.

Abstract: ASCII characters are coded in the form of 8, 16 or longer digital words. Signal pulses with durations proportional to such digital words are generated and filtered so that the filtered signal has substantially the same duration as the unfiltered signal. The filtered signal fits within the voiceband so that it can be transmitted through a voiceband medium such as a telephone network. At the receiver, zero-crossings of the received signal are detected and from the duration between consecutive zero-crossings, the particular ASCII represented by the duration of such signal may be recovered.