Patents by Inventor Edward A. Keehr

Edward A. Keehr 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).

  • Publication number: 20220173801
    Abstract: An adjustable payload for small geostationary communication satellites is disclosed. In an example, a communication satellite includes a payload system having a software defined payload that is configured to provide communication services. The software defined payload includes a processor for providing at least one of gain control per transponder and carrier/sub-channel, channelization, channel routing, signal conditioning or equalization, spectrum analysis, interference detection, regenerative or modem processing, bandwidth flexibility, digital beamforming, digital pre-distortion or power amplifier linearization, for at least one user slice for a plurality of user terminals and at least one gateway slice for a gateway station. The software defined payload also includes an input side and an output side for each slice. Each input side includes an input filter and an analog-to-digital converter and each output side includes an output filter and a digital-to-analog converter.
    Type: Application
    Filed: February 21, 2022
    Publication date: June 2, 2022
    Inventors: John Gedmark, Steven Joseph, Ryan McLinko, Braedon Salz, Edward Keehr, Karl Clausing, Siamak Ebadi
  • Patent number: 10972150
    Abstract: An RFID interrogator transceiver with various improvements is proposed. A digital interface element implemented in a field-programmable gate array permits the use of a low-cost, low pin count microcontroller unit to control various integrated circuits within the transceiver both with the complexity afforded by the microcontroller unit and with the speed afforded by the field-programmable gate array. A transmit waveform generation architecture which can store opcodes in a segmented random access memory permits both leisurely loading of information over a digital interface from a low-cost microcontroller unit and fast playback over a wireless interface during low-latency RFID exchanges. Finally, a dual digital second-order resonator infinite-impulse-response filter permits a more hardware efficient channel bandpass filter solution than a finite-impulse-response filter and can be easily adjusted to accommodate RFID backscatter link frequencies and frequency tolerances.
    Type: Grant
    Filed: December 4, 2018
    Date of Patent: April 6, 2021
    Assignee: SUPERLATIVE SEMICONDUCTOR, LLC
    Inventor: Edward A. Keehr
  • Publication number: 20200177272
    Abstract: An adjustable payload for small geostationary communication satellites is disclosed. In an example, a communication satellite includes a payload system having a software defined payload that is configured to provide communication services. The software defined payload includes a processor for providing at least one of gain control per transponder and carrier/sub-channel, channelization, channel routing, signal conditioning or equalization, spectrum analysis, interference detection, regenerative or modem processing, bandwidth flexibility, digital beamforming, digital pre-distortion or power amplifier linearization, for at least one user slice for a plurality of user terminals and at least one gateway slice for a gateway station. The software defined payload also includes an input side and an output side for each slice. Each input side includes an input filter and an analog-to-digital converter and each output side includes an output filter and a digital-to-analog converter.
    Type: Application
    Filed: November 29, 2019
    Publication date: June 4, 2020
    Inventors: John Gedmark, Steven Joseph, Ryan McLinko, Braedon Salz, Ali Younis, Edward Keehr, Karl Clausing, Siamak Ebadi
  • Publication number: 20190173528
    Abstract: An RFID interrogator transceiver with various improvements is proposed. A digital interface element implemented in a field-programmable gate array permits the use of a low-cost, low pin count microcontroller unit to control various integrated circuits within the transceiver both with the complexity afforded by the microcontroller unit and with the speed afforded by the field-programmable gate array. A transmit waveform generation architecture which can store opcodes in a segmented random access memory permits both leisurely loading of information over a digital interface from a low-cost microcontroller unit and fast playback over a wireless interface during low-latency RFID exchanges. Finally, a dual digital second-order resonator infinite-impulse-response filter permits a more hardware efficient channel bandpass filter solution than a finite-impulse-response filter and can be easily adjusted to accommodate RFID backscatter link frequencies and frequency tolerances.
    Type: Application
    Filed: December 4, 2018
    Publication date: June 6, 2019
    Inventor: Edward A. Keehr
  • Patent number: 10187120
    Abstract: A tunable microwave network and its application in a radio transceiver transmit signal cancellation network is described. The tunable microwave network realizes a large set of reflection coefficients over a predefined area in the complex reflection coefficient plane for the purpose of reflecting a variable cancellation signal which, when properly configured, results in the substantial attenuation of transmit reflection and transmit leakage signal at the radio transceiver receiver input. A relevant building block of the proposed tunable microwave network is a shunt tunable capacitive element coupled to another shunt tunable capacitive element through a phase shifting element with phase shift greater than 30 degrees divided by a quantity substantially similar to the total number of said tunable capacitive elements and less than 60 degrees at a predefined frequency.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: January 22, 2019
    Assignee: SUPERLATIVE SEMICONDUCTOR, LLC
    Inventor: Edward A. Keehr
  • Patent number: 9900060
    Abstract: A tunable microwave network and its application in a radio transceiver transmit signal cancellation network is described. The tunable microwave network realizes a large set of reflection coefficients over a predefined area in the complex reflection coefficient plane for the purpose of reflecting a variable cancellation signal which, when properly configured, results in the substantial attenuation of transmit reflection and transmit leakage signal at the radio transceiver receiver input. A relevant building block of the proposed tunable microwave network is a shunt tunable capacitive element coupled to another shunt tunable capacitive element through a phase shifting element with phase shift greater than 30 degrees divided by a quantity substantially similar to the total number of said tunable capacitive elements and less than 60 degrees at a predefined frequency.
    Type: Grant
    Filed: May 12, 2016
    Date of Patent: February 20, 2018
    Assignee: Superlative Semiconductor, LLC
    Inventor: Edward A. Keehr
  • Patent number: 8971834
    Abstract: Third-order intermodulation products (IM3) are attenuated in RF receivers by providing a typical main signal path and a parallel auxiliary signal path in which the IM3 products are accentuated, and the output from the main signal path is adaptively filtered to attenuate the IM3 products. In one embodiment, a multirate filter bank (MRFB) with asymmetric analysis and synthesis sections is used to detect and isolate the IM3 products. In another embodiment an analog nonlinear term generator is placed at the front of the auxiliary signal path. The analog nonlinear term generator takes advantage of the nonlinearities of a differential MOSFET circuit and a multiplier to extract the IM3 products in the RF input signal. The outputs of the main signal path and the auxiliary signal path are inputs to a complex least mean squares filter to attenuate the IM3 products in the resulting signal.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: March 3, 2015
    Assignee: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Patent number: 8290449
    Abstract: A feedforward error-compensated receiver for minimizing undesired odd-order nonlinear distortion products. The receiver includes a first receiver path configured to receive an input signal. The first receiver path outputs a signal including at least one baseband (BB) frequency. At least one second receiver path is configured to receive the input signal and to provide a second receiver path output signal. The second receiver path includes at least one odd-order nonlinear distortion reference generator. The at least one odd-order nonlinear distortion reference generator and the mixer are configured to generate a synthetic odd-order nonlinear distortion signal. A combining element is configured to receive the output signal from the first path and the output signal from the second receiver path output and to combine the signals such that the odd-order nonlinear distortion signals are substantially attenuated at an output of the combining element.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: October 16, 2012
    Assignee: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Patent number: 8233871
    Abstract: An incompressible receiver for minimizing undesired higher-order nonlinear distortion products includes a first receiver path configured to receive an input signal having at least one non-baseband frequency. A second receiver path is also configured to receive the input signal. The second receiver path includes at least one odd-order nonlinear distortion reference component and at least one even-order nonlinear distortion reference component. The distortion reference components are configured to be in an “on” state or in an “off” state. A combining element is configured to combine input signals from the first and second receiver paths such that the higher-order nonlinear distortion signals are substantially attenuated at an output of the combining element. An incompressible receiver that has an odd-order nonlinear distortion reference generator including a cubic term and at least one additional term of order greater than 3 and an incompressible receiver front end amplifier (IRFEA) are also described.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: July 31, 2012
    Assignee: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Patent number: 8150356
    Abstract: A polynomial nonlinear term generator is configured to receive an RF signal. An analog cubic term generator generates an analog cubic term signal and an analog square term generator generates an analog square term signal, both derived from the RF signal. A cubic term mixer assembly mixes a local oscillator (LO) signal with the cubic term signal to generate a synthetic IM3 signal. A square term ADC provides a digital square term signal and a cubic term ADC provides a digital cubic term signal. At least one digital multiplier has a first multiplier input terminal configured to receive a selected one of the digital square term signal and the digital cubic term signal, and a second multiplier input terminal configured to receive the digital square term signal. The multiplier provides as output a digital IMn product where n is greater than 3. A corresponding method is also described.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: April 3, 2012
    Assignee: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Patent number: 8077878
    Abstract: An integrated circuit within a cellular telephone has a wake mode and a sleep mode. In the wake mode, a voltage regulator supplies a regulated voltage onto a MIC BIAS terminal. This voltage biases a microphone of a headset/microphone accessory that is coupled to the cellular telephone. If the user presses a switch on the accessory, then a large current is drawn out of the MIC BIAS terminal. This switch press condition is detected by an ADC within the integrated circuit. In the sleep mode, the regulator and ADC are disabled to conserve power. A novel switch detect circuit supplies a current out of the MIC BIAS terminal at an unregulated voltage. If the user presses the switch, then the current supplied from the MIC BIAS terminal increases. This switch press condition is detected over temperature, voltage and process conditions by a special inverter in the switch detect circuit.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: December 13, 2011
    Assignee: QUALCOMM Incorporated
    Inventor: Edward A. Keehr
  • Publication number: 20110110473
    Abstract: Third-order intermodulation products (IM3) are attenuated in RF receivers by providing a typical main signal path and a parallel auxiliary signal path in which the IM3 products are accentuated, and the output from the main signal path is adaptively filtered to attenuate the IM3 products. In one embodiment, a multirate filter bank (MRFB) with asymmetric analysis and synthesis sections is used to detect and isolate the IM3 products. In another embodiment an analog nonlinear term generator is placed at the front of the auxiliary signal path. The analog nonlinear term generator takes advantage of the nonlinearities of a differential MOSFET circuit and a multiplier to extract the IM3 products in the RF input signal. The outputs of the main signal path and the auxiliary signal path are inputs to a complex least mean squares filter to attenuate the IM3 products in the resulting signal.
    Type: Application
    Filed: November 23, 2010
    Publication date: May 12, 2011
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Patent number: 7894788
    Abstract: Third-order intermodulation products (IM3) are attenuated in RF receivers by providing a typical main signal path and a parallel auxiliary signal path in which the IM3 products are accentuated, and the output from the main signal path is adaptively filtered to attenuate the IM3 products. In one embodiment, a multirate filter bank (MRFB) with asymmetric analysis and synthesis sections is used to detect and isolate the IM3 products. In another embodiment an analog nonlinear term generator is placed at the front of the auxiliary signal path. The analog nonlinear term generator takes advantage of the nonlinearities of a differential MOSFET circuit and a multiplier to extract the IM3 products in the RF input signal. The outputs of the main signal path and the auxiliary signal path are inputs to a complex least mean squares filter to attenuate the IM3 products in the resulting signal.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: February 22, 2011
    Assignee: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Publication number: 20100316172
    Abstract: An incompressible receiver for minimizing undesired higher-order nonlinear distortion products includes a first receiver path configured to receive an input signal having at least one non-baseband frequency. A second receiver path is also configured to receive the input signal. The second receiver path includes at least one odd-order nonlinear distortion reference component and at least one even-order nonlinear distortion reference component. The distortion reference components are configured to be in an “on” state or in an “off” state. A combining element is configured to combine input signals from the first and second receiver paths such that the higher-order nonlinear distortion signals are substantially attenuated at an output of the combining element. An incompressible receiver that has an odd-order nonlinear distortion reference generator including a cubic term and at least one additional term of order greater than 3 and an incompressible receiver front end amplifier (IRFEA) are also described.
    Type: Application
    Filed: June 16, 2010
    Publication date: December 16, 2010
    Applicant: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Publication number: 20100176981
    Abstract: A polynomial nonlinear term generator is configured to receive an RF signal. An analog cubic term generator generates an analog cubic term signal and an analog square term generator generates an analog square term signal, both derived from the RF signal. A cubic term mixer assembly mixes a local oscillator (LO) signal with the cubic term signal to generate a synthetic IM3 signal. A square term ADC provides a digital square term signal and a cubic term ADC provides a digital cubic term signal. At least one digital multiplier has a first multiplier input terminal configured to receive a selected one of the digital square term signal and the digital cubic term signal, and a second multiplier input terminal configured to receive the digital square term signal. The multiplier provides as output a digital IMn product where n is greater than 3. A corresponding method is also described.
    Type: Application
    Filed: January 13, 2010
    Publication date: July 15, 2010
    Applicant: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Publication number: 20090075612
    Abstract: A feedforward error-compensated receiver for minimizing undesired odd-order nonlinear distortion products. The receiver includes a first receiver path configured to receive an input signal. The first receiver path outputs a signal including at least one baseband (BB) frequency. At least one second receiver path is configured to receive the input signal and to provide a second receiver path output signal. The second receiver path includes at least one odd-order nonlinear distortion reference generator. The at least one odd-order nonlinear distortion reference generator and the mixer are configured to generate a synthetic odd-order nonlinear distortion signal. A combining element is configured to receive the output signal from the first path and the output signal from the second receiver path output and to combine the signals such that the odd-order nonlinear distortion signals are substantially attenuated at an output of the combining element.
    Type: Application
    Filed: September 18, 2008
    Publication date: March 19, 2009
    Applicant: California Institute of Technology.
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Publication number: 20090075610
    Abstract: Third-order intermodulation products (IM3) are attenuated in RF receivers by providing a typical main signal path and a parallel auxiliary signal path in which the IM3 products are accentuated, and the output from the main signal path is adaptively filtered to attenuate the IM3 products. In one embodiment, a multirate filter bank (MRFB) with asymmetric analysis and synthesis sections is used to detect and isolate the IM3 products. In another embodiment an analog nonlinear term generator is placed at the front of the auxiliary signal path. The analog nonlinear term generator takes advantage of the nonlinearities of a differential MOSFET circuit and a multiplier to extract the IM3 products in the RF input signal. The outputs of the main signal path and the auxiliary signal path are inputs to a complex least mean squares filter to attenuate the IM3 products in the resulting signal.
    Type: Application
    Filed: May 21, 2007
    Publication date: March 19, 2009
    Applicant: California Institute of Technology
    Inventors: Edward Keehr, Seyed Ali Hajimiri
  • Publication number: 20080044004
    Abstract: An integrated circuit within a cellular telephone has a wake mode and a sleep mode. In the wake mode, a voltage regulator supplies a regulated voltage onto a MIC BIAS terminal. This voltage biases a microphone of a headset/microphone accessory that is coupled to the cellular telephone. If the user presses a switch on the accessory, then a large current is drawn out of the MIC BIAS terminal. This switch press condition is detected by an ADC within the integrated circuit. In the sleep mode, the regulator and ADC are disabled to conserve power. A novel switch detect circuit supplies a current out of the MIC BIAS terminal at an unregulated voltage. If the user presses the switch, then the current supplied from the MIC BIAS terminal increases. This switch press condition is detected over temperature, voltage and process conditions by a special inverter in the switch detect circuit.
    Type: Application
    Filed: July 26, 2006
    Publication date: February 21, 2008
    Inventor: Edward A. Keehr
  • Patent number: 6956515
    Abstract: A digital to analog converter augmented with Direct Charge Transfer (DCT) techniques. A digital to analog converter augmented with DCT and CDS techniques. A digital to analog converter augmented with Postfilter Droop Compensation.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: October 18, 2005
    Assignee: QUALCOMM, Incorporated
    Inventors: Edward A. Keehr, Sean Wang, Seyfollah Bazarjani
  • Publication number: 20040070528
    Abstract: A digital to analog converter augmented with Direct Charge Transfer (DCT) techniques. A digital to analog converter augmented with DCT and CDS techniques. A digital to analog converter augmented with Postfilter Droop Compensation.
    Type: Application
    Filed: June 17, 2003
    Publication date: April 15, 2004
    Inventors: Edward A. Keehr, Sean Wang, Seyfollah Bazarjani