Abstract: A multi-phase (N) power supply is presented having current shared power factor correction. This includes N input rectifier filters each receiving a respective different one of an N phase AC input signal and providing therefrom one of N rectified signals. N single phase power factor correction pre-regulators each receive a respective different one of the rectified signals and provide therefrom a regulated signal. A current sharing N way to single way multiplexing switch network receives the N regulated signals and provides therefrom a single output signal.

Abstract: A pulse step modulator employs a plurality of series connected unit step power amplifier modules. Each module is turned on by a turn-on signal to provide a unit step voltage of a given value. An output circuit is connected to the modules for providing an output voltage to a load and wherein the output voltage is a multiple of the unit step voltages in dependence upon the number of modules that are turned on. The modules are sequentially turned on in a given order and are turned off in the reverse order. An encoder provides turn-on signals with each turn-on signal being applied to a selected one of the modules. The number of turn-on signals provided varies as a function of the magnitude of a time varying input signal. A controller alternately turns enables or disables (in a swapping manner) one of a pair of associated modules as the magnitude of the input signal increases and decreases.

Abstract: A multi-phase (N) power supply is presented having current shared power factor correction, comprising. This includes N input rectifier filters each receiving a respective different one of an N phase AC input signal and providing therefrom one of N rectified signals. N single phase power factor correction pre-regulators receives a respective different one of the rectified signals and provide therefrom a regulated signal. A current sharing N way to single way multiplexing switch network for receiving the N regulated signals and provides therefrom a single output signal.

Abstract: A digital amplitude modulation (AM) transmitter with pulse width modulating RF drive is presented. A plurality of RF amplifiers, each, when turned on, amplifies an applied RF drive signal by the same amount to provide a unit step RF output. An encoder supplies turn-on signals to turn on a number of the RF amplifiers wherein the number varies as a function of the value of an applied audio signal. The width of the unit step RF output is varied as a function of the number of the RF amplifiers that are turned on.

Abstract: A pulse step modulator employs a plurality of series connected unit step power amplifier modules. Each module is turned on by a turn-on signal to provide a unit step voltage of a given value. An output circuit is connected to the modules for providing an output voltage to a load and wherein the output voltage is a multiple of the unit step voltages in dependence upon the number of modules that are turned on. The modules are sequentially turned on in a given order and are turned off in the reverse order. An encoder provides turn-on signals with each turn-on signal being applied to a selected one of the modules. The number of turn-on signals provided varies as a function of the magnitude of a time varying input signal. A controller alternately turns enables or disables (in a swapping manner) one of a pair of associated modules as the magnitude of the input signal increases and decreases.

Abstract: A power supply for an RF transmitting tube while protecting the tube from a high voltage arc event. The supply includes a rectifier circuit configured to be connected to an AC voltage supply and having an output circuit that supplies a DC voltage to a load including the tube and wherein the DC voltage may have a ripple voltage thereon. A control circuit is located intermediate the output circuit and the load for reducing any ripple voltage. The control circuit includes a series solid state switch that is connected in series between the rectifier circuit and the load. The control circuit also includes a reference capacitor coupled to the output circuit and to the load for supplying a reference voltage to the switch so that a voltage at the output circuit that exceeds the reference voltage will be clipped to reduce the voltage that is applied to the load.

Abstract: A circuit for use in a broadcast transmitter for adaptively compensating for carrier signal distortions caused by amplitude modulating an RF carrier signal. The circuit includes a modulator/amplifier network that receives an RF carrier signal and modulates it by a received amplitude varying signal to obtain therefrom a modulated carrier signal which may exhibit distortions caused by the amplitude modulating of the RF carrier signal. A digitally adaptive corrector precorrects the amplitude varying signal prior to application thereof to the network to compensate for any modulated carrier signal distortions. This includes a digital processor that provides signal correction as a function of digital samples representing amplitude variations of the modulated RF carrier signal.

Abstract: A pulse width modulator is presented herein and it includes a pulse width driver circuit that receives a time varying ramp signal that is modulated by a time varying analog input signal to produce a pulse width modulated drive signal comprised of turn-on pulses having widths that vary with variations in the magnitude of said input signal. A switch is turned on by each drive pulse for a time duration dependent upon the duration of each drive pulse and provides an output signal therefrom. A negative bias amplifier provides a negative bias signal that has pulsations that are synchronized with said drive pulses but of opposite phase. A combiner combines output signal with the negative bias signal to provide a combined output signal.

Abstract: A pulse width modulation apparatus includes a load circuit, a signal switch, a shunt switch, and a resistor. The signal switch isolates the load circuit from a voltage source along a signal path. The shunt switch is connected to the signal path at a point between the signal switch and the load circuit. The shunt switch isolates the signal path from a ground voltage. A resistor is connected in series between the signal switch and the shunt switch.

Abstract: A circuit for use in a broadcast transmitter for adaptively compensating for carrier signal distortions caused by amplitude modulating an RF carrier signal. The circuit includes a modulator/amplifier network that receives an RF carrier signal and modulates it by a received amplitude varying signal to obtain therefrom a modulated carrier signal which may exhibit distortions caused by the amplitude modulating of the RF carrier signal. A digitally adaptive corrector precorrects the amplitude varying signal prior to application thereof to the network to compensate for any modulated carrier signal distortions. This includes a digital processor that provides signal correction as a function of digital samples representing amplitude variations of the modulated RF carrier signal.

Abstract: A system and method are provided for providing nonlinear precorrection to an input signal. A plurality of nonlinear function blocks each receive a constituent signal, derived from the input signal. Each constituent signal has an associated value and an associated delay. The nonlinear function blocks output an intermediate signal having a value equal to that of an associated memoryless nonlinear function evaluated at the value of the constituent signal. A summation function sums the plurality of intermediate signals to obtain a system output.

Abstract: A pulse width modulation apparatus includes a load circuit, a signal switch, a shunt switch, and a resistor. The signal switch isolates the load circuit from a voltage source along a signal path. The shunt switch is connected to the signal path at a point between the signal switch and the load circuit. The shunt switch isolates the signal path from a ground voltage. A resistor is connected in series between the signal switch and the shunt switch.

Abstract: An RF amplifier system having improved power supply is presented and which includes a plurality of power amplifiers each having an output circuit for connecting a DC voltage source to one of a plurality of primary windings located on a first transformer. The first transformer has a plurality of secondary windings located thereon with each being a single turn secondary winding. The secondary windings are connected together in series. A second transformer is located in a cascaded arrangement with the first transformer and has a like plurality of single turn primary windings connected together in series and a like plurality of secondary windings are on said second transformer with each being connected to a rectifier for providing a controlled DC voltage.

Abstract: An RF amplifier system having improved power supply is presented and which includes a plurality of power amplifiers each having an output circuit for connecting a DC voltage source to one of a plurality of primary windings located on a first transformer. The first transformer has a plurality of secondary windings located thereon with each being a single turn secondary winding. The secondary windings are connected together in series. A second transformer is located in a cascaded arrangement with the first transformer and has a like plurality of single turn primary windings connected together in series and a like plurality of secondary windings are on said second transformer with each being connected to a rectifier for providing a controlled DC voltage.

Abstract: An AM transmitter having tracking power supply compensation. A first power supply provides a constant DC operating voltage. A second power supply is responsive to an input signal, such that the second power supply provides a DC voltage when an amplitude associated with the input signal exceeds a predetermined level. N RF amplifiers amplify the input signal. Each of the plurality of amplifiers are connected to the first and second power supplies. Each of the amplifiers has an output circuit that, when the associated amplifier is on, supplies energy from the first and second power supplies to provide an output voltage to a load.

Abstract: An AM transmitter having feed forward correction to compensate for source impedance. A power supply source provides a DC operating voltage. N RF amplifiers are provided for amplifying an input signal. The amplifiers are connected to the power supply source. Each amplifier has an output circuit that, when the associated amplifier is on, supplies energy from the source to provide an output voltage at a load. Each the amplifier output circuit exhibits a source impedance that degrades the value of the output voltage. A source impedance corrector varies the value of the input signal prior to amplification by the amplifiers to compensate for any variations in the value of the output voltage caused by the source impedances.

Abstract: An RF amplifier system comprising a plurality of actuatable switches, each switch being normally OFF and being actuated to an ON condition by a received turn ON pulse and remains ON for the duration of the turn ON pulse. The switches are connected in a series circuit with a load across a DC voltage source. An RF source provides a train of RF pulses exhibiting a fixed frequency and fixed duty-cycle and wherein each RF pulse is of a fixed magnitude and duration. A control circuit receives the RF pulses and provides therefrom the turn ON pulses which are of equal duration and which are synchronized to the RF pulses. The control circuit simultaneously applies the turn ON pulses to the plurality of transistor switches. The control circuit includes a pulse duration modulator that varies the duration of the turn ON pulses.

Abstract: An RF power amplifier system is presented herein and it includes an RF source that provides an RF carrier signal having a given RF carrier frequency. An RF amplifier module amplifies the carrier signal and this module includes first and second RF amplifiers having a common input to receive a turn on signal that turns on both amplifiers and wherein the outputs of the amplifiers are coupled together in parallel. A controller supplies a turn on signal to the common input to turn on the first and second amplifiers. A first AC to DC supply provides a first DC operating voltage obtained from a first multiphase AC supply and applies this to the amplifier module and wherein the first DC voltage exhibits a ripple frequency dependent upon the number of phases in the first multiphase supply.

Abstract: An RF power amplifier system is provided having a DC voltage source for providing an input DC voltage. An RF source provides an RF cattier signal. An RF amplifier serves to amplifier the carrier signal. A DC to DC power supply provides operating voltage to the RF amplifier wherein the operating voltage exhibits a desired percentage of the input voltage. The DC to DC supply includes a low pass filter having a capacitor. A switching device is periodically turned on by turn on pulses for periodically applying the input voltage to the filter which then provides an output voltage across the capacitor. The output voltage serves as the operating voltage. A pulse generator provides the turn on pulses at a frequency synchronized to the frequency of the carrier signal. The turn on pulses exhibit a duty cycle that varies as a function of the value of a control signal. A comparator compares the input voltage with the output voltage and provides the control signal with a value that varies as a function of the comparison.

Abstract: A RF power amplifier system is presented including a RF source for providing a train of RF pulses exhibiting RF cycles of a fixed frequency and wherein each pulse is of a fixed amplitude and duration. A bridge circuit including a first transistor switch for, when on, connecting a DC voltage source across the load for DC current flow therethrough in a first direction and a second transistor switch for, when on, connecting said DC voltage source across said load for DC current flow therethrough in a second direction. A switch driver for, when enabled, passes the RF pulses for driving the first and second transistor switches on and off at a frequency dependent upon that of the RF pulses and in such a manner that current from the DC voltage source alternately flows in the first and second directions through the load. A driver controller provides turn-on signals and selectively applies them to the switch driver for enabling the switch driver for passing the RF pulses to the transistor switches.