Patents by Inventor Radjindrepersad Gajadharsing
Radjindrepersad Gajadharsing has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240106396Abstract: The present invention relates to a push-pull amplifying unit and a Doherty amplifier. The push-pull amplifying unit comprises a first amplifier, a second amplifier, a first shunt inductor, and a second shunt inductor. The first and second shunt inductors have mutually connected second terminals and are inductively coupled to increase the impedance between the first output and the virtual ground and the impedance between the second output and the virtual ground at a fundamental frequency of a signal to be amplified by the push-pull amplifying unit relative to those impedances in the absence of said inductive coupling, and to decrease the impedance between the first output and the virtual ground and the impedance between the second output and the virtual ground at a second harmonic frequency of the signal to be amplified relative to those impedances in the absence of said inductive coupling.Type: ApplicationFiled: February 4, 2022Publication date: March 28, 2024Inventors: Mohammad Reza BEIKMIRZA, Seyed Morteza ALAVI, Leonardus Cornelis Nicolaas DE VREEDE, Freerk VAN RIJS, Radjindrepersad GAJADHARSING
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Publication number: 20230299728Abstract: Example embodiments relate to Doherty amplifiers. One example includes a radiofrequency (RF) power amplifier. The RF power amplifier includes an input lead. The RF power amplifier also includes a first output lead. Additionally, the RF power amplifier includes a first semiconductor die arranged in between the input lead and the first output lead. The first semiconductor die includes a first edge arranged adjacent to the input lead and an opposing second edge arranged adjacent to the first output lead. Further, the RF power amplifier includes a field-effect transistor integrated on the first semiconductor die. The field-effect transistor includes a gate bondpad assembly and a drain bondpad assembly. The field-effect transistor also includes a plurality of gate bondwires and a plurality of drain bondwires. In addition, the field-effect transistor includes a plurality of gate fingers extending in a first direction and a plurality of drain fingers extending in a second direction.Type: ApplicationFiled: March 14, 2023Publication date: September 21, 2023Inventors: Junlei Zhao, Yi Zhu, Radjindrepersad Gajadharsing
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Publication number: 20230283240Abstract: Example embodiments relate to radiofrequency, RF, amplifiers and electronic devices that include RF amplifiers. One example RF amplifier includes a splitter configured to split an RF input signal received at an input of the RF amplifier into a plurality of RF signal parts. The RF amplifier also includes a plurality of Doherty amplifiers, each Doherty amplifier having a main amplifier and a peak amplifier. Each Doherty amplifier is configured to amplify a respective RF signal part and output a respective amplified RF signal part. Additionally, the RF amplifier includes a combiner. The combiner is configured to combine the amplified RF signal parts from the plurality of Doherty amplifiers into an RF output signal and output the RE output signal. The combiner includes a plurality of inputs and an output. Each input of the combiner is connected to an output of a respective Doherty amplifier among the plurality of Doherty amplifiers.Type: ApplicationFiled: March 6, 2023Publication date: September 7, 2023Inventors: Junlei Zhao, Mohadig Widha Rousstia, Radjindrepersad Gajadharsing
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Patent number: 8928402Abstract: A device including a Doherty amplifier, the Doherty amplifier having an amplifier input and output. At least one main amplifier is coupled to the input via a main input impedance and to the output via a main output impedance and additional amplifiers, each amplifier being coupled to the input via respective additional input impedances. Each additional amplifier has a respective additional amplifier output coupled to a respective pair of additional impedances connected in series and having a respective connection node between them. The device also has a first additional amplifier having their respective additional impedances coupled between its respective output and the amplifier output, the pair of additional impedances having first and second impedances, the first impedance being connected to the respective additional amplifier output and to the connection node, the second impedance being coupled between their respective connection node and the connection node of the previous additional amplifier.Type: GrantFiled: December 4, 2012Date of Patent: January 6, 2015Assignee: NXP, B.V.Inventor: Radjindrepersad Gajadharsing
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Patent number: 8357979Abstract: An electronic device comprising a field-effect transistor having an inter digitated structure suitable for high-frequency power applications, and having multiple threshold voltages that are provided in different regions of each a segment of the interdigitated structure. This leads to a dramatic improvement in linearity over a large power range in the back-off region under class AB signal operation.Type: GrantFiled: April 28, 2004Date of Patent: January 22, 2013Assignee: NXP B.V.Inventors: Thomas Christian Roedle, Hendrikus Ferdinand Franciscus Jos, Stephan Jo Cecile Henri Theeuwen, Petra Christina Anna Hammes, Radjindrepersad Gajadharsing
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Patent number: 8022760Abstract: A 3-way Doherty amplifier has an amplifier input and an amplifier output. The amplifier has a main stage, a first peak stage and a second peak stage. The amplifier has an input network connecting the amplifier input to the inputs of the stages, and an output network connecting the stages to the amplifier output. The output network implements a phase shift of 90° between the output of the main stage and the amplifier output; a phase shift of 180° between the output of the first peak stage and the amplifier output; and a phase shift of 90° between the third output and the amplifier output.Type: GrantFiled: December 18, 2008Date of Patent: September 20, 2011Assignee: NXP B.V.Inventors: Radjindrepersad Gajadharsing, Weng Chuen Edmund Neo, Marco Johannes Pelk, Leonardus Cornelis Nicolaas De Vreede, Ji Zhao
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Patent number: 7920029Abstract: A radio frequency power amplifier has first and second amplifier stages coupled in series, one of which is operated in class F and the other is operated in inverse class F; an envelope detector adapted to detect an envelope of the input signal; a power supply coupled to supply an electrical supply voltage to the first and second amplifier stages, wherein the electrical supply voltage is controlled to follow the envelope of the input signal. Such amplifier makes it possible to maintain class F and inverse class F operation, respectively, of the first and second amplifier stages independent on the input signal. Preferably, this is done by controlling the electrical supply voltage so that the saturation levels of the first and second amplifier stages follow the envelope of the input signal.Type: GrantFiled: February 6, 2007Date of Patent: April 5, 2011Assignee: NXP B.V.Inventors: Igor Blednov, Radjindrepersad Gajadharsing
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Publication number: 20100315162Abstract: A 3-way Doherty amplifier has an amplifier input and an amplifier output. The amplifier has a main stage, a first peak stage and a second peak stage. The amplifier has an input network connecting the amplifier input to the inputs of the stages, and an output network connecting the stages to the amplifier output. The output network implements a phase shift of 90° between the output of the main stage and the amplifier output; a phase shift of 180° between the output of the first peak stage and the amplifier output; and a phase shift of 90° between the third output and the amplifier output.Type: ApplicationFiled: December 18, 2008Publication date: December 16, 2010Applicant: NXP B.V.Inventors: Radjindrepersad Gajadharsing, W. C. E Neo, M. Pelk, L. C. N. De Vreede, Ji Zhao
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Publication number: 20100164632Abstract: A radio frequency power amplifier has first and second amplifier stages coupled in series, one of which is operated in class F and the other is operated in inverse class F; an envelope detector adapted to detect an envelope of the input signal; a power supply coupled to supply an electrical supply voltage to the first and second amplifier stages, wherein the electrical supply voltage is controlled to follow the envelope of the input signal. Such amplifier makes it possible to maintain class F and inverse class F operation, respectively, of the first and second amplifier stages independent on the input signal. Preferably, this is done by controlling the electrical supply voltage so that the saturation levels of the first and second amplifier stages follow the envelope of the input signal.Type: ApplicationFiled: February 6, 2007Publication date: July 1, 2010Applicant: NXP B.V.Inventors: Igor Blednov, Radjindrepersad Gajadharsing
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Patent number: 7652316Abstract: The invention relates to in particular a lateral DMOST with a drain extension (8). In the known transistor a further metal strip (20) is positioned between the gate electrode contact strip and the drain contact (16) which is electrically connected with the source region contact (15). In the device proposed here, the connection between the further metal strip (20) and the source contact (15,12) comprises a capacitor (30) and the further metal strip (20) is provided with a further contact region (35) for delivering a voltage to the further metal strip (20). In this way an improved linearity is possible and the usefulness of the device is improved in particular at high power and at high frequencies. Preferably the capacitor (30) is integrated with the transistor in a single semiconductor body (1). The invention further comprises a method of operating a device (10) according to the invention.Type: GrantFiled: April 21, 2004Date of Patent: January 26, 2010Assignee: DSP Group Switzerland AGInventors: Radjindrepersad Gajadharsing, Thomas Christian Roedle, Petra Christina Anna Hammes, Stephan Jo Cecile Henri Theeuwen
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Publication number: 20060231905Abstract: An electronic device comprising a field-effect transistor having an inter digitated structure suitable for high-frequency power applications, and having multiple threshold voltages that are provided in different regions of each a segment of the interdigitated structure. This leads to a dramatic improvement in linearity over a large power range in the back-off region under class AB signal operation.Type: ApplicationFiled: April 28, 2004Publication date: October 19, 2006Inventors: Thomas Roedle, Hendrikus Jos, Stephan Theeuwen, Petra Hammes, Radjindrepersad Gajadharsing
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Publication number: 20060220154Abstract: The invention relates to in particular a lateral DMOST with a drain extension (8). In the known transistor a further metal strip (20) is positioned between the gate electrode contact strip and the drain contact (16) which is electrically connected with the source region contact (15). In the device proposed here, the connection between the further metal strip (20) and the source contact (15,12) comprises a capacitor (30) and the further metal strip (20) is provided with a further contact region (35) for delivering a voltage to the further metal strip (20). In this way an improved linearity is possible and the usefulness of the device is improved in particular at high power and at high frequencies. Preferably the capacitor (30) is integrated with the transistor in a single semiconductor body (1). The invention further comprises a method of operating a device (10) according to the invention.Type: ApplicationFiled: April 21, 2004Publication date: October 5, 2006Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Radjindrepersad Gajadharsing, Thomas Roedle, Petra Hammes, Stephan Theeuwen