Patents by Inventor Mamatha Deshpande
Mamatha Deshpande 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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Patent number: 10461757Abstract: An apparatus, comprising a first sampling circuit configured to sample a clock signal according to a data signal to produce a first sampled signal, a second sampling circuit configured to sample the clock signal according to a delay signal to produce a second sampled signal, and a control circuit coupled to the first sampling circuit and the second sampling circuit, wherein the control circuit is configured to perform a not-and (NAND) operation according to the first sampled signal and the second sampled signal to produce an activation signal for activating a frequency adjustment for the clock signal.Type: GrantFiled: December 29, 2016Date of Patent: October 29, 2019Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Gong Lei, Yen Dang, Yifan Gu, Hungyi Lee, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Patent number: 10396805Abstract: A reference-less frequency detector circuit includes a sampling circuit that is configured to generate a frequency control voltage and a switch circuit control signal based on a frequency difference between a clock signal frequency and an input data rate. The frequency control voltage has a frequency down indication and a frequency up indication. A voltage-to-current converter circuit is coupled to the sampling circuit and is configured to convert the frequency control voltage to a frequency control current based on the switch circuit control signal. The voltage-to-current converter circuit includes an output switch circuit controlled by the switch control signal and is configured to have substantially equal respective latencies for the frequency down indication and the frequency up indication.Type: GrantFiled: August 31, 2018Date of Patent: August 27, 2019Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Yifan Gu, Hung-Yi Lee, Mamatha Deshpande, Shou-Po Shih, Miao Liu
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Publication number: 20180375522Abstract: A reference-less frequency detector circuit includes a sampling circuit that is configured to generate a frequency control voltage and a switch circuit control signal based on a frequency difference between a clock signal frequency and an input data rate. The frequency control voltage has a frequency down indication and a frequency up indication. A voltage-to-current converter circuit is coupled to the sampling circuit and is configured to convert the frequency control voltage to a frequency control current based on the switch circuit control signal. The voltage-to-current converter circuit includes an output switch circuit controlled by the switch control signal and is configured to have substantially equal respective latencies for the frequency down indication and the frequency up indication.Type: ApplicationFiled: August 31, 2018Publication date: December 27, 2018Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Yifan Gu, Hung-Yi Lee, Mamatha Deshpande, Shou-Po Shih, Miao Liu
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Patent number: 10122348Abstract: A multiplexer comprises: an output circuit comprising a multiplexer output; and a first buffer coupled to the output circuit and comprising: a first selection input configured to receive a first selection signal; a first logical input configured to receive a first logical input signal; and a first ground; wherein the multiplexer is configured to: couple the first logical input to the multiplexer output when the first selection signal is a first value; and couple the first logical input to the first ground when the first selection signal is a second value. A method comprises: receiving a selection signal and a first logical input signal; coupling a first logical input to a multiplexer output when the selection signal is a first value; and coupling the first logical input to a ground when the selection signal is a second value.Type: GrantFiled: March 30, 2016Date of Patent: November 6, 2018Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Gong Lei, Yen Dang, Yifan Gu, Hungyi Lee, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Patent number: 10116470Abstract: An apparatus comprising an input port configured to receive an input signal propagated through a transmission link, wherein the transmission link comprises a low-frequency channel loss and a high-frequency channel loss, a continuous-time linear equalization (CTLE) circuit coupled to the input port and configured to produce an output signal according to the input signal by applying a first gain to the input signal at a first frequency to compensate the low-frequency loss, and applying a second gain to the input signal at a second frequency to compensate the high-frequency channel loss, and an output port coupled to the CTLE circuit and configured to output the output signal.Type: GrantFiled: October 28, 2015Date of Patent: October 30, 2018Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Hungyi Lee, Yifan Gu, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Patent number: 10097190Abstract: A reference-less frequency detector circuit includes a sampling circuit that is configured to generate a frequency control voltage and a switch circuit control signal based on a frequency difference between a clock signal frequency and an input data rate. The frequency control voltage has a frequency down indication and a frequency up indication. A voltage-to-current converter circuit is coupled to the sampling circuit and is configured to convert the frequency control voltage to a frequency control current based on the switch circuit control signal. The voltage-to-current converter circuit includes an output switch circuit controlled by the switch control signal and is configured to have substantially equal respective latencies for the frequency down indication and the frequency up indication.Type: GrantFiled: December 29, 2016Date of Patent: October 9, 2018Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Yifan Gu, Hung-Yi Lee, Mamatha Deshpande, Shou-Po Shih, Miao Liu
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Publication number: 20180175865Abstract: A reference-less frequency detector circuit includes a sampling circuit that is configured to generate a frequency control voltage and a switch circuit control signal based on a frequency difference between a clock signal frequency and an input data rate. The frequency control voltage has a frequency down indication and a frequency up indication. A voltage-to-current converter circuit is coupled to the sampling circuit and is configured to convert the frequency control voltage to a frequency control current based on the switch circuit control signal. The voltage-to-current converter circuit includes an output switch circuit controlled by the switch control signal and is configured to have substantially equal respective latencies for the frequency down indication and the frequency up indication.Type: ApplicationFiled: December 29, 2016Publication date: June 21, 2018Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Yifan Gu, Hung-Yi Lee, Mamatha Deshpande, Shou-Po Shih, Miao Liu
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Patent number: 9941958Abstract: An apparatus comprising a semiconductor chip that comprises an optical modulator configured to modulate an optical signal based on a received driver signal, a voltage-mode (VM) driver coupled to the optical modulator and configured to produce a level-shifted driver signal to modulate the optical signal, and a two-stage test interface coupled to the optical modulator and configured to receive and test the level shifted driver signal. The two-stage test interface comprises a voltage equalization stage coupled to an output-terminated buffer stage, the VM driver comprises a two-stage VM Mach-Zehnder modulator (MZM) driver that comprises a pre-driver coupled to a VM level-shifter (VMLS). The apparatus further comprises a resistor coupled to an output of the buffer stage, wherein the resistor comprises an amount of resistance that matches a termination resistance of a test equipment. The termination resistance is about 50 ohm (?).Type: GrantFiled: December 15, 2015Date of Patent: April 10, 2018Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Yifan Gu, Hungyi Lee, Gong Lei, Yen Dang, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Publication number: 20170288652Abstract: A multiplexer comprises: an output circuit comprising a multiplexer output; and a first buffer coupled to the output circuit and comprising: a first selection input configured to receive a first selection signal; a first logical input configured to receive a first logical input signal; and a first ground; wherein the multiplexer is configured to: couple the first logical input to the multiplexer output when the first selection signal is a first value; and couple the first logical input to the first ground when the first selection signal is a second value. A method comprises: receiving a selection signal and a first logical input signal; coupling a first logical input to a multiplexer output when the selection signal is a first value; and coupling the first logical input to a ground when the selection signal is a second value.Type: ApplicationFiled: March 30, 2016Publication date: October 5, 2017Inventors: Liang Gu, Yuming Cao, Gong Lei, Yen Dang, Yifan Gu, Hungyi Lee, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Publication number: 20170170894Abstract: An apparatus comprising a semiconductor chip that comprises an optical modulator configured to modulate an optical signal based on a received driver signal, a voltage-mode (VM) driver coupled to the optical modulator and configured to produce a level-shifted driver signal to modulate the optical signal, and a two-stage test interface coupled to the optical modulator and configured to receive and test the level shifted driver signal. The two-stage test interface comprises a voltage equalization stage coupled to an output-terminated buffer stage, the VM driver comprises a two-stage VM Mach-Zehnder modulator (MZM) driver that comprises a pre-driver coupled to a VM level-shifter (VMLS). The apparatus further comprises a resistor coupled to an output of the buffer stage, wherein the resistor comprises an amount of resistance that matches a termination resistance of a test equipment. The termination resistance is about 50 ohm (?).Type: ApplicationFiled: December 15, 2015Publication date: June 15, 2017Inventors: Liang Gu, Yuming Cao, Yifan Gu, Hungyi Lee, Gong Lei, Yen Dang, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Publication number: 20170126443Abstract: An apparatus comprising an input port configured to receive an input signal propagated through a transmission link, wherein the transmission link comprises a low-frequency channel loss and a high-frequency channel loss, a continuous-time linear equalization (CTLE) circuit coupled to the input port and configured to produce an output signal according to the input signal by applying a first gain to the input signal at a first frequency to compensate the low-frequency loss, and applying a second gain to the input signal at a second frequency to compensate the high-frequency channel loss, and an output port coupled to the CTLE circuit and configured to output the output signal.Type: ApplicationFiled: October 28, 2015Publication date: May 4, 2017Inventors: Liang Gu, Yuming Cao, Yen Dang, Gong Lei, Hungyi Lee, Yifan Gu, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Publication number: 20170126236Abstract: An apparatus, comprising a first sampling circuit configured to sample a clock signal according to a data signal to produce a first sampled signal, a second sampling circuit configured to sample the clock signal according to a delay signal to produce a second sampled signal, and a control circuit coupled to the first sampling circuit and the second sampling circuit, wherein the control circuit is configured to perform a not-and (NAND) operation according to the first sampled signal and the second sampled signal to produce an activation signal for activating a frequency adjustment for the clock signal.Type: ApplicationFiled: December 29, 2016Publication date: May 4, 2017Inventors: Liang Gu, Yuming Cao, Gong Lei, Yen Dang, Yifan Gu, Hungyi Lee, Mamatha Deshpande, Shou-Po Shih, Yan Duan
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Patent number: 9584303Abstract: An apparatus, comprising a first sampling circuit configured to sample a clock signal according to a data signal to produce a first sampled signal, a second sampling circuit configured to sample the clock signal according to a delay signal to produce a second sampled signal, and a control circuit coupled to the first sampling circuit and the second sampling circuit, wherein the control circuit is configured to perform a not-and (NAND) operation according to the first sampled signal and the second sampled signal to produce an activation signal for activating a frequency adjustment for the clock signal.Type: GrantFiled: October 28, 2015Date of Patent: February 28, 2017Assignee: Futurewei Technologies, Inc.Inventors: Liang Gu, Yuming Cao, Gong Lei, Yen Dang, Yifan Gu, Hungyi Lee, Mamatha Deshpande, Shou-Po Shih, Yan Duan