Patents Assigned to NUJIRA LTD.
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Patent number: 8989682Abstract: Apparatus and methods for envelope tracking calibration are provided. In one embodiment, a method of calibrating an envelope tracker having an envelope shaping table generated at a desired gain compression of a power amplifier is provided. The method includes generating a supply voltage for the power amplifier using the envelope tracker, operating the supply voltage of the power amplifier at a first voltage level associated with substantially no gain compression of the power amplifier, and measuring an output power of the power amplifier at the first voltage level. The method further includes decreasing a voltage level of the supply voltage one or more times and measuring the output power at each voltage level, determining a second voltage level of the power amplifier associated with a gain compression equal to about that of the desired gain compression, and calibrating the envelope tracker based on the determination.Type: GrantFiled: February 6, 2012Date of Patent: March 24, 2015Assignees: Skyworks Solutions, Inc., Nujira Ltd.Inventors: David Steven Ripley, Sabah Khesbak, Benjamin Bartram, Kevin Lee Cobley, Robert Astle Henshaw, Julian Hildersley, Robert John Thompson
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Patent number: 8786371Abstract: Apparatus and methods for voltage converters are provided. In one embodiment, a voltage conversion system includes a bypass circuit and a voltage converter including an inductor and a plurality of switches configured to control a current through the inductor. The bypass circuit includes a first p-type field effect transistor (PFET), a second PFET, a first n-type field effect transistor (NFET), and a second NFET. The first and second NFET transistors and the first and second PFET transistors are electrically connected between a first end and a second end of the inductor such that a source of the first PFET transistor and a drain of the first NFET transistor are electrically connected to the first end of the inductor and such that a drain of the second PFET transistor and a source of the second NFET transistor are electrically connected to the second end of the inductor.Type: GrantFiled: November 7, 2012Date of Patent: July 22, 2014Assignees: Skyworks Solutions, Inc., Nujira LtdInventors: Peter Harris Robert Popplewell, Jakub F Pingot, Florinel G Balteanu, Martin Wilson, Mark Tuckwell
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Publication number: 20130127548Abstract: Apparatus and methods for voltage converters are provided. In one embodiment, a voltage conversion system includes a bypass circuit and a voltage converter including an inductor and a plurality of switches configured to control a current through the inductor. The bypass circuit includes a first p-type field effect transistor (PFET), a second PFET, a first n-type field effect transistor (NFET), and a second NFET. The first and second NFET transistors and the first and second PFET transistors are electrically connected between a first end and a second end of the inductor such that a source of the first PFET transistor and a drain of the first NFET transistor are electrically connected to the first end of the inductor and such that a drain of the second PFET transistor and a source of the second NFET transistor are electrically connected to the second end of the inductor.Type: ApplicationFiled: November 7, 2012Publication date: May 23, 2013Applicants: NUJIRA LTD, Skyworks Solutions, Inc.Inventors: Skyworks Solutions, Inc., NUJIRA LTD
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Publication number: 20120200354Abstract: Apparatus and methods for envelope tracking calibration are provided. In one embodiment, a method of calibrating an envelope tracker having an envelope shaping table generated at a desired gain compression of a power amplifier is provided. The method includes generating a supply voltage for the power amplifier using the envelope tracker, operating the supply voltage of the power amplifier at a first voltage level associated with substantially no gain compression of the power amplifier, and measuring an output power of the power amplifier at the first voltage level. The method further includes decreasing a voltage level of the supply voltage one or more times and measuring the output power at each voltage level, determining a second voltage level of the power amplifier associated with a gain compression equal to about that of the desired gain compression, and calibrating the envelope tracker based on the determination.Type: ApplicationFiled: February 6, 2012Publication date: August 9, 2012Applicants: NUJIRA LTD, SKYWORKS SOLUTIONS, INC.Inventors: David Steven Ripley, Sabah Khesbak, Benjamin Bartram, Kevin Lee Cobley, Robert Astle Henshaw, Julian Hildersley, Robert John Thompson
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Publication number: 20090128236Abstract: A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.Type: ApplicationFiled: January 27, 2009Publication date: May 21, 2009Applicant: NUJIRA LTD.Inventor: Martin Paul Wilson
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Publication number: 20070279019Abstract: There is disclosed a voltage summer including a transformer having a primary side and a secondary side, wherein a first voltage to be summed is connected to the primary side and a second voltage to be summed is connected to the secondary side. There is further disclosed a transformer comprising a primary winding and a secondary winding and having a turns ratio of primary winding to secondary winding of x:y, providing x turns in series in the primary winding and providing y turns in series in the secondary winding; providing an equal number of turns in the primary and secondary windings; and closely coupling each primary winding turn with a secondary winding turn.Type: ApplicationFiled: December 7, 2004Publication date: December 6, 2007Applicant: NUJIRA LTD.Inventor: Martin Wilson
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Publication number: 20070273449Abstract: A power amplifier circuit comprising a transistor for receiving a signal to be amplified at an input and for outputting an amplified signal at an output; a modulated power supply connected to the transistor output; and a resistive element connected at the transistor output such that a low impedance is maintained at the transistor output across a range of operational frequencies.Type: ApplicationFiled: February 9, 2005Publication date: November 29, 2007Applicant: Nujira Ltd.Inventor: Martin Wilson
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Publication number: 20070210771Abstract: There is disclosed a power supply stage (202), comprising: generating means for generating a power supply voltage from a high efficiency variable voltage supply (204) in dependence on a reference signal; adjusting means for receiving the generated power supply voltage (220), and adapted to provide an adjusted selected power supply voltage tracking the reference signal (216) in dependence thereon.Type: ApplicationFiled: August 25, 2005Publication date: September 13, 2007Applicant: NUJIRA LTD.Inventors: Martin Wilson, Shane Flint
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Publication number: 20060028271Abstract: There is disclosed a radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.Type: ApplicationFiled: August 19, 2005Publication date: February 9, 2006Applicant: NUJIRA LTD.Inventor: Martin Wilson