Patents by Inventor David C. M. Pham
David C. M. Pham 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: 10476445Abstract: An exemplary system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: GrantFiled: February 27, 2018Date of Patent: November 12, 2019Assignee: Aviat U.S., Inc.Inventors: Frank Matsumoto, Youming Qin, David C. M. Pham, Jayesh Nath, Ying Shen
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Publication number: 20180191311Abstract: An exemplary system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: ApplicationFiled: February 27, 2018Publication date: July 5, 2018Applicant: Aviat U.S., Inc.Inventors: Frank Matsumoto, Youming Qin, David C.M. Pham, Jayesh Nath, Ying Shen
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Patent number: 9906194Abstract: An exemplary system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: GrantFiled: May 17, 2016Date of Patent: February 27, 2018Assignee: Aviat U.S., Inc.Inventors: Frank Matsumoto, Youming Qin, David C. M. Pham, Jayesh Nath, Ying Shen
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Patent number: 9531412Abstract: Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal.Type: GrantFiled: May 5, 2015Date of Patent: December 27, 2016Assignee: Aviat U.S., Inc.Inventors: Jayesh Nath, Ying Shen, Frank Matsumoto, Youming Qin, David C. M. Pham
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Publication number: 20160261240Abstract: An exemplary system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: ApplicationFiled: May 17, 2016Publication date: September 8, 2016Applicant: Aviat U.S., Inc.Inventors: Frank Matsumoto, Youming Qin, David C.M. Pham, Jayesh Nath, Ying Shen
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Patent number: 9369094Abstract: An exemplary system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: GrantFiled: October 20, 2011Date of Patent: June 14, 2016Assignee: Aviat U.S., Inc.Inventors: Frank Matsumoto, Youming Qin, David C. M. Pham
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Publication number: 20150236732Abstract: Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal.Type: ApplicationFiled: May 5, 2015Publication date: August 20, 2015Applicant: Aviat U.S., Inc.Inventors: Jayesh Nath, Ying Shen, Frank Matsumoto, Youming Qin, David C.M. Pham
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Patent number: 9065397Abstract: Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal.Type: GrantFiled: January 11, 2012Date of Patent: June 23, 2015Assignee: Aviat U.S., Inc.Inventors: Jayesh Nath, Ying Shen, Frank Matsumoto, Youming Qin, David C. M. Pham
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Patent number: 8816791Abstract: Systems and methods for a filtering wave energy using a rectangular-to-circular waveguide transition are discussed herein. An exemplary system comprises a rectangular-to-circular waveguide transition and a filter card. The rectangular-to-circular waveguide transition may include a front section and a back section opposite the front section, the rectangular-to-circular waveguide transition defining a circular hole extending from the front section of the rectangular-to-circular waveguide transition through the back section, the rectangular-to-circular waveguide transition further having a first arcuate region on the face of the transition, the first arcuate region defining a first cavity extending from the circular hole through the first arcuate region, the rectangular-to-circular waveguide transition also having a second arcuate region defining a second cavity opposite the first cavity, the second cavity extending from the circular hole through the second arcuate region.Type: GrantFiled: August 30, 2011Date of Patent: August 26, 2014Assignee: Aviat U.S., Inc.Inventors: Cuong Nguyen, David C. M. Pham, Jayesh Nath, John Ruiz, Thuan Huynh
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Publication number: 20120208477Abstract: Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal.Type: ApplicationFiled: January 11, 2012Publication date: August 16, 2012Inventors: Jayesh NATH, Ying Shen, Frank Matsumoto, Yougming Qin, David C.M. Pham
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Publication number: 20120108188Abstract: In one example system, the system comprises a linearizer module, a first upconverter module, a power amplifier module, a signal sampler module, and a downconverter module. The linearizer module may be configured to receive a first intermediate frequency signal and to adjust the first intermediate frequency signal based on a reference signal and a signal based on a second intermediate frequency signal. The first upconverter module may be configured to receive and up-convert a signal based on the adjusted first intermediate frequency signal to a radio frequency signal. The power amplifier module may be configured to receive and amplify a power of a signal based on the radio frequency signal. The signal sampler module may be configured to sample a signal based on the amplified radio frequency signal. The downconverter module may be configured to receive and down-convert a signal based on the sampled radio frequency signal to the second intermediate frequency signal.Type: ApplicationFiled: October 20, 2011Publication date: May 3, 2012Inventors: Frank MATSUMOTO, Youming Qin, David C.M. Pham
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Publication number: 20120075040Abstract: Systems and methods for a filtering wave energy using a rectangular-to-circular waveguide transition are discussed herein. An exemplary system comprises a rectangular-to-circular waveguide transition and a filter card. The rectangular-to-circular waveguide transition may include a front section and a back section opposite the front section, the rectangular-to-circular waveguide transition defining a circular hole extending from the front section of the rectangular-to-circular waveguide transition through the back section, the rectangular-to-circular waveguide transition further having a first arcuate region on the face of the transition, the first arcuate region defining a first cavity extending from the circular hole through the first arcuate region, the rectangular-to-circular waveguide transition also having a second arcuate region defining a second cavity opposite the first cavity, the second cavity extending from the circular hole through the second arcuate region.Type: ApplicationFiled: August 30, 2011Publication date: March 29, 2012Inventors: Cuong Nguyen, David C.M. Pham, Jayesh Nath, John Ruiz, Thuan Huynh
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Patent number: 8116058Abstract: The present invention contemplates systems and methods for distributing RF and DC signals and detecting, logging and suppressing surge energy associated with surge events such as lightning and power line surges. The detection and logging is provided in order to determine possible causes of a failure and who might be responsible for the repair. The suppression is provided in order to protect electrical equipment such as split mount wireless radio systems from catastrophic failure due to surge events.Type: GrantFiled: July 6, 2010Date of Patent: February 14, 2012Assignee: Harris Stratex Networks Operating CorporationInventors: Youming Qin, Frank S. Matsumoto, David C. M. Pham
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Publication number: 20100265626Abstract: The present invention contemplates systems and methods for distributing RF and DC signals and detecting, logging and suppressing surge energy associated with surge events such as lightning and power line surges. The detection and logging is provided in order to determine possible causes of a failure and who might be responsible for the repair. The suppression is provided in order to protect electrical equipment such as split mount wireless radio systems from catastrophic failure due to surge events.Type: ApplicationFiled: July 6, 2010Publication date: October 21, 2010Inventors: Youming Qin, Frank S. Matsumoto, David C. M. Pham
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Patent number: 7751169Abstract: The present invention contemplates systems and methods for distributing RF and DC signals and detecting, logging and suppressing surge energy associated with surge events such as lightning and power line surges. The detection and logging is provided in order to determine possible causes of a failure and who might be responsible for the repair. The suppression is provided in order to protect electrical equipment such as split mount wireless radio systems from catastrophic failure due to surge events.Type: GrantFiled: October 2, 2006Date of Patent: July 6, 2010Assignee: Harris Stratex Networks Operating CorporationInventors: Youming Qin, Frank S. Matsumoto, David C. M. Pham
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Publication number: 20080102761Abstract: A frequency synthesizer module with phase hits compensation, comprises an enclosure; a frequency synthesizer within the enclosure; and a heater module including a heater element in thermal communication with the frequency synthesizer for producing heat to adaptively adjust frequency synthesizer temperature. The frequency synthesizer module may be in an ODU and electrically isolated from the heater module. The heater module may include a posistor that varies based on temperature; and a voltage regulator having an input pin for receiving a varying input voltage, an output pin for providing a modifiable output voltage to the heater element for adaptively adjusting the heat generated thereby, and an adjust pin coupled to the posistor for maintaining a substantially constant voltage at the adjust pin. The heater module may heat when below room temperature, heat at less than maximum power when between room temperature and a threshold, and deactivate when above the threshold.Type: ApplicationFiled: October 27, 2006Publication date: May 1, 2008Inventors: David C.M. Pham, Frank S. Matsumoto, Youming Qin
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Publication number: 20080080116Abstract: The present invention contemplates systems and methods for distributing RF and DC signals and detecting, logging and suppressing surge energy associated with surge events such as lightning and power line surges. The detection and logging is provided in order to determine possible causes of a failure and who might be responsible for the repair. The suppression is provided in order to protect electrical equipment such as split mount wireless radio systems from catastrophic failure due to surge events.Type: ApplicationFiled: October 2, 2006Publication date: April 3, 2008Inventors: Youming Qin, Frank S. Matsumoto, David C. M. Pham
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Patent number: 7242725Abstract: An adaptive broadband post-distortion receiver for wireless digital communications improves performance of a wireless digital communications system. The improved performance of the system includes improved linear AM-AM and AM-PM responses approaching saturation. Indeed, the proposed adaptive broadband post-distortion receiver has an effect on attributes such as bit error rate and transmitter power efficiency and, in turn, on modulation and bandwidth. The adaptive broadband post-distortion receiver is configured with an adaptively controlled IF post-distorter located at the IF stage of the receiver. The placement of the distortion canceling function in the IF section of the receiver lends itself to broadband applications. The post-distorter is configured to cancels the distortion produced by the transmitter and receiver as it is adaptively controlled using bit error rate calculations. The distortion canceling utilizes bit error rate information that is otherwise available in the receiver.Type: GrantFiled: April 2, 2003Date of Patent: July 10, 2007Assignee: Harris Stratex Networks Operating CorporationInventors: Frank S. Matsumoto, David C. M. Pham
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Publication number: 20040196921Abstract: An adaptive broadband post-distortion receiver for wireless digital communications improves performance of a wireless digital communications system. The improved performance of the system includes improved linear AM-AM and AM-PM responses approaching saturation. Indeed, the proposed adaptive broadband post-distortion receiver has an effect on attributes such as bit error rate and transmitter power efficiency and, in turn, on modulation and bandwidth. The adaptive broadband post-distortion receiver is configured with an adaptively controlled IF post-distorter located at the IF stage of the receiver. The placement of the distortion canceling function in the IF section of the receiver lends itself to broadband applications. The post-distorter is configured to cancels the distortion produced by the transmitter and receiver as it is adaptively controlled using bit error rate calculations. The distortion canceling utilizes bit error rate information that is otherwise available in the receiver.Type: ApplicationFiled: April 2, 2003Publication date: October 7, 2004Applicant: Stratex Networks, Inc.Inventors: Frank S. Matsumoto, David C. M. Pham