Method and apparatus for reducing a ripple signal in an output of a direct current power supply
First Claim
1. A method for reducing an output ripple signal of a power supply for supplying a direct current (DC) voltage and current to a load, the method comprising step of:
- sensing one of the output ripple signal and an intermediate ripple signal to produce a control signal;
generating a rectangular pulse carrier signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy, wherein the rectangular pulse carrier signal operates at a frequency substantially higher than the control signal; and
coupling the PWM signal into a portion of the power supply through a transformer, the transformer arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal.
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0 Petitions
Accused Products
Abstract
A method and apparatus reduces an output ripple signal of a power supply (200) for supplying a DC voltage and current to a load. One of the output ripple signal and an intermediate ripple signal is sensed to produce a control signal at a ripple sensing element (206), and a rectangular pulse carrier signal is generated by a pulse width modulator (302), the signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy. The rectangular pulse carrier signal operates at a frequency substantially higher than the control signal. The PWM signal is coupled into a portion of the power supply through a transformer (202). The transformer is arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal.
40 Citations
20 Claims
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1. A method for reducing an output ripple signal of a power supply for supplying a direct current (DC) voltage and current to a load, the method comprising step of:
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sensing one of the output ripple signal and an intermediate ripple signal to produce a control signal; generating a rectangular pulse carrier signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy, wherein the rectangular pulse carrier signal operates at a frequency substantially higher than the control signal; and coupling the PWM signal into a portion of the power supply through a transformer, the transformer arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A power supply for supplying a direct current (DC) voltage and current to a load and for generating a reduced output ripple signal, the power supply comprising:
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a ripple sensing element for sensing one of the output ripple signal and an intermediate ripple signal to produce a control signal; a pulse width modulator coupled to the ripple sensing element for generating a rectangular pulse carrier signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy, wherein the rectangular pulse carrier signal operates at a frequency substantially higher than the control signal; and a transformer coupled to the pulse width modulator for coupling the PWM signal into a portion of the power supply, the transformer arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A radio communication transmitter, comprising:
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a carrier generator for generating a radio frequency carrier; a modulator coupled to the carrier generator for modulating the radio frequency carrier to produce a modulated carrier; a power amplifier coupled to the modulator for amplifying the modulated carrier; and a power supply coupled to at least one of the carrier generator, the modulator, and the power amplifier for supplying a direct current (DC) voltage and current thereto, and for generating a reduced output ripple signal, the power supply comprising; a ripple sensing element for sensing one of the output ripple signal and an intermediate ripple signal to produce a control signal; a pulse width modulator coupled to the ripple sensing element for generating a rectangular pulse carrier signal having a duty cycle modulated with the control signal to produce a pulse width modulated (PWM) signal carrying ripple signal energy, wherein the rectangular pulse carrier signal operates at a frequency substantially higher than the control signal; and a transformer coupled to the pulse width modulator for coupling the PWM signal into a portion of the power supply, the transformer arranged such that the PWM signal is combined with the intermediate ripple signal at an amplitude and relative phase sufficient to substantially reduce the output ripple signal. - View Dependent Claims (18, 19, 20)
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Specification