Patents by Inventor Rajagopalan Rangarajan
Rajagopalan Rangarajan 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: 20240106490Abstract: A transmit (TX) local oscillator (LO) leakage calibration circuit including a transceiver having a transmit portion and a receive portion, an interface circuit connected to the transmit portion and the receive portion, an impedance control circuit connected to a low noise amplifier (LNA) in the receive portion, the impedance control circuit configured to adjust an input impedance for the LNA, a power detector coupled to an output of the LNA, and a local oscillator cancellation element connected to the power detector, the local oscillator cancellation element configured to adjust an input to the transmit portion based on TX LO leakage detected by the power detector.Type: ApplicationFiled: September 22, 2022Publication date: March 28, 2024Inventors: Chinmaya MISHRA, Abdellatif BELLAOUAR, Damin CAO, Rajagopalan RANGARAJAN, Kevin Hsi-Huai WANG
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Publication number: 20240097749Abstract: Methods, systems, and devices for wireless communication are described. In some systems, a user equipment (UE) may transmit, to a network entity, a first signal including a request to update a resolution of a phase shifting operation associated with beam-based communications. The UE may receive, from the network entity, a second signal approving the request. The UE may communicate using a beam according to an updated resolution of the phase shifting operation based on the second signal approving the request. Additionally, or alternatively, the UE may transmit a first signal including a request to suspend a beam refinement process based on the resolution of the phase shifting operation. The UE may receive a second signal approving the request to suspend the beam refinement process. The UE may communicate with the network entity using a beam based on suspending further beam refinement in response to the second signal.Type: ApplicationFiled: September 16, 2022Publication date: March 21, 2024Inventors: Vasanthan Raghavan, Shrenik Patel, Rajagopalan Rangarajan, Damin Cao, Kang Yang, Jung Ho Ryu, Junyi Li
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Patent number: 11632098Abstract: An example apparatus includes a polyphase transconductance-capacitor filter. The polyphase filter includes a DC bias voltage node, a plus in-phase filter unit, a minus in-phase filter unit, a plus quadrature-phase filter unit, and a minus quadrature-phase filter unit. Each filter unit respectively includes an input node, an output node, and a control node. The polyphase filter also includes a plus in-phase switch and a minus in-phase switch. The plus in-phase switch is coupled to the control node of the plus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit. The minus in-phase switch is coupled to the control node of the minus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit.Type: GrantFiled: March 24, 2021Date of Patent: April 18, 2023Assignee: QUALCOMM IncorporatedInventors: Timothy Donald Gathman, Lai Kan Leung, Chirag Dipak Patel, Xinmin Yu, Rajagopalan Rangarajan
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Publication number: 20230073817Abstract: Certain aspects of the present disclosure generally relate to jamming detection for radio frequency (RF) front-end circuitry. For example, certain aspects provide an apparatus having a first counter configured to count a number of times that a power of a reception signal exceeds a first threshold. The apparatus also includes a second counter configured to count a number of measurements of the power of the reception signal. The apparatus further includes control logic having a first input coupled to an output of the first counter and having a second input coupled to an output of the second counter. The control logic is configured to determine an amount of jamming over a measurement window based on the number of times that the power of the reception signal exceeds the first threshold and on the number of measurements.Type: ApplicationFiled: September 7, 2021Publication date: March 9, 2023Inventors: Peter SHAH, Ajay Devadatta KANETKAR, Siavash EKBATANI, Yuanning YU, Shrenik PATEL, Dongjiang QIAO, Rajagopalan RANGARAJAN
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Publication number: 20220311423Abstract: An example apparatus includes a polyphase transconductance-capacitor filter. The polyphase filter includes a DC bias voltage node, a plus in-phase filter unit, a minus in-phase filter unit, a plus quadrature-phase filter unit, and a minus quadrature-phase filter unit. Each filter unit respectively includes an input node, an output node, and a control node. The polyphase filter also includes a plus in-phase switch and a minus in-phase switch. The plus in-phase switch is coupled to the control node of the plus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit. The minus in-phase switch is coupled to the control node of the minus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit.Type: ApplicationFiled: March 24, 2021Publication date: September 29, 2022Inventors: Timothy Donald Gathman, Lai Kan Leung, Chirag Dipak Patel, Xinmin Yu, Rajagopalan Rangarajan
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Patent number: 11398853Abstract: A transformer-based antenna switching network includes a transformer having a secondary winding that extends between a first terminal and a second terminal. The first terminal couples to ground through a first switch and connects to a first antenna. The second terminal couples to ground through a second switch and connects to a second antenna.Type: GrantFiled: October 8, 2019Date of Patent: July 26, 2022Assignee: QUALCOMM IncorporatedInventors: Chinmaya Mishra, Marco Vigilante, Chirag Dipak Patel, Bhushan Shanti Asuri, Rajagopalan Rangarajan
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Publication number: 20220207428Abstract: In certain aspects, a receiver includes first amplifiers, wherein each one of the first amplifiers comprises an input and an output. The receiver also includes second amplifiers, wherein each one of the second amplifiers comprises an input and an output, and the outputs of the second amplifiers are coupled to a combining node. The receiver also includes transmission lines, wherein each one of the transmission lines is coupled between the output of a respective one of the first amplifiers and the input of a respective one of the second amplifiers. The receiver further includes a load coupled to the combining node, and receiver elements, wherein each one of the receiver elements comprises an input and an output, and the output of each one of the receiver elements is coupled to the input of a respective one of the first amplifiers.Type: ApplicationFiled: March 18, 2022Publication date: June 30, 2022Inventors: Lai Kan LEUNG, Xinmin YU, Chirag Dipak PATEL, Rajagopalan RANGARAJAN
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Patent number: 11290058Abstract: A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.Type: GrantFiled: October 22, 2020Date of Patent: March 29, 2022Assignee: QUALCOMM IncorporatedInventors: Yue Chao, Yinghan Wang, Marco Zanuso, Rajagopalan Rangarajan
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Patent number: 11283409Abstract: In certain aspects, a receiver includes first amplifiers, wherein each one of the first amplifiers comprises an input and an output. The receiver also includes second amplifiers, wherein each one of the second amplifiers comprises an input and an output, and the outputs of the second amplifiers are coupled to a combining node. The receiver also includes transmission lines, wherein each one of the transmission lines is coupled between the output of a respective one of the first amplifiers and the input of a respective one of the second amplifiers. The receiver further includes a load coupled to the combining node, and receiver elements, wherein each one of the receiver elements comprises an input and an output, and the output of each one of the receiver elements is coupled to the input of a respective one of the first amplifiers.Type: GrantFiled: August 30, 2019Date of Patent: March 22, 2022Assignee: QUALCOMM IncorporatedInventors: Lai Kan Leung, Xinmin Yu, Chirag Dipak Patel, Rajagopalan Rangarajan
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Patent number: 11025260Abstract: An apparatus is disclosed that implements a phase-locked loop (PLL) that uses multiple error determiners as part of a feedback loop. In an example aspect, an apparatus for generating a frequency includes a PLL. The PLL includes a loop filter, a voltage-controlled oscillator (VCO), a frequency divider, and multiple error determiners. The loop filter includes a filter input node and a filter output node. The VCO includes a VCO input node and a VCO output node. The VCO input node is coupled to the filter output node. The frequency divider includes a divider input node and multiple divider output nodes. The divider input node is coupled to the VCO output node. The multiple error determiners are coupled between the multiple divider output nodes and the filter input node.Type: GrantFiled: August 26, 2020Date of Patent: June 1, 2021Assignee: QUALCOMM IncorporatedInventors: Yue Chao, Marco Zanuso, Rajagopalan Rangarajan, Yiwu Tang
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Patent number: 10990117Abstract: Certain aspects of the present disclosure provide a low drop-out (LDO) regulator. The LDO regulator generally includes a first p-type metal-oxide-semiconductor transistor (PMOS) having a drain coupled to an output node of the LDO regulator, a first amplifier having an input coupled to a reference voltage node and an output coupled to a gate of the first PMOS transistor, a second PMOS transistor having a source coupled to the output node, and a second amplifier having an input coupled to the output node and an output coupled to a gate of the second PMOS transistor.Type: GrantFiled: September 5, 2019Date of Patent: April 27, 2021Assignee: QUALCOMM IncorporatedInventors: Yue Chao, Marco Zanuso, Rajagopalan Rangarajan, Yiwu Tang
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Publication number: 20210105047Abstract: A transformer-based antenna switching network includes a transformer having a secondary winding that extends between a first terminal and a second terminal. The first terminal couples to ground through a first switch and connects to a first antenna. The second terminal couples to ground through a second switch and connects to a second antenna.Type: ApplicationFiled: October 8, 2019Publication date: April 8, 2021Inventors: Chinmaya MISHRA, Marco VIGILANTE, Chirag Dipak PATEL, Bhushan Shanti ASURI, Rajagopalan RANGARAJAN
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Publication number: 20210072778Abstract: Certain aspects of the present disclosure provide a low drop-out (LDO) regulator. The LDO regulator generally includes a first p-type metal-oxide-semiconductor transistor (PMOS) having a drain coupled to an output node of the LDO regulator, a first amplifier having an input coupled to a reference voltage node and an output coupled to a gate of the first PMOS transistor, a second PMOS transistor having a source coupled to the output node, and a second amplifier having an input coupled to the output node and an output coupled to a gate of the second PMOS transistor.Type: ApplicationFiled: September 5, 2019Publication date: March 11, 2021Inventors: Yue CHAO, Marco ZANUSO, Rajagopalan RANGARAJAN, Yiwu TANG
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Publication number: 20210067099Abstract: In certain aspects, a receiver includes first amplifiers, wherein each one of the first amplifiers comprises an input and an output. The receiver also includes second amplifiers, wherein each one of the second amplifiers comprises an input and an output, and the outputs of the second amplifiers are coupled to a combining node. The receiver also includes transmission lines, wherein each one of the transmission lines is coupled between the output of a respective one of the first amplifiers and the input of a respective one of the second amplifiers. The receiver further includes a load coupled to the combining node, and receiver elements, wherein each one of the receiver elements comprises an input and an output, and the output of each one of the receiver elements is coupled to the input of a respective one of the first amplifiers.Type: ApplicationFiled: August 30, 2019Publication date: March 4, 2021Inventors: Lai Kan LEUNG, Xinmin YU, Chirag Dipak PATEL, Rajagopalan RANGARAJAN
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Publication number: 20210044253Abstract: A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.Type: ApplicationFiled: October 22, 2020Publication date: February 11, 2021Inventors: Yue CHAO, Yinghan WANG, Marco ZANUSO, Rajagopalan RANGARAJAN
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Patent number: 10848100Abstract: A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.Type: GrantFiled: September 17, 2018Date of Patent: November 24, 2020Assignee: QUALCOMM IncorporatedInventors: Yue Chao, Yinghan Wang, Marco Zanuso, Rajagopalan Rangarajan
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Patent number: 10664001Abstract: A circuit includes a first transistor that conducts a first current responsive to a DC bias voltage and an RF signal. A second transistor conducts a second current responsive to the DC bias voltage. The first current and the second current are mirrored through a pair of current mirrors coupled together through a low-pass filter to filter the envelope of the RF signal.Type: GrantFiled: March 18, 2019Date of Patent: May 26, 2020Assignee: QUALCOMM IncorporatedInventors: Mohamed Abouzied, Rajagopalan Rangarajan, Peter Shah
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Publication number: 20200091866Abstract: A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.Type: ApplicationFiled: September 17, 2018Publication date: March 19, 2020Inventors: Yue CHAO, Yinghan WANG, Marco ZANUSO, Rajagopalan RANGARAJAN
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Publication number: 20200073428Abstract: A circuit includes a first transistor that conducts a first current responsive to a DC bias voltage and an RF signal. A second transistor conducts a second current responsive to the DC bias voltage. The first current and the second current are mirrored through a pair of current mirrors coupled together through a low-pass filter to filter the envelope of the RF signal.Type: ApplicationFiled: March 18, 2019Publication date: March 5, 2020Inventors: Mohamed Abouzied, Rajagopalan Rangarajan, Peter Shah
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Patent number: 10439858Abstract: An apparatus includes a low noise amplifier (LNA) multiplexer configured to receive a plurality of radio frequency (RF) signals at a plurality of input terminals and to combine the plurality of RF signals into a combined RF signal that is output at an output terminal. The LNA multiplexer includes a plurality of input signal paths, and each input signal path is coupleable to a respective input terminal of the plurality of input terminals and is configured to receive a respective RF signal of the plurality of RF signals. The apparatus further includes an LNA demultiplexer configured to receive the combined RF signal at an input port coupled to the output terminal and to distribute the combined RF signal to a plurality of output ports, each output port of the plurality of output ports configured to output the combined RF signal to a respective downconverter of a plurality of downconverters.Type: GrantFiled: September 25, 2017Date of Patent: October 8, 2019Assignee: QUALCOMM IncorporatedInventors: Aleksandar Miodrag Tasic, Chiewcharn Narathong, Christian Holenstein, Dongling Pan, Yiwu Tang, Rajagopalan Rangarajan, Lai Kan Leung