Patents Assigned to RFAXIS, Inc.
  • Patent number: 10097171
    Abstract: A RF switch circuit includes a voltage divider circuit and a semiconductor device. The semiconductor device has an activated state and a deactivated state. The voltage divider circuit has an input terminal connected to a first line and an output terminal connected to a second line. The first line is connected to a power source. A gate terminal of the semiconductor device is connected to the second line. In the activated state, a source terminal and a drain terminal of the semiconductor device are each selectively connected to ground. In the deactivated state, the source terminal and the drain terminal of the semiconductor device are each selectively connected to the power source.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: October 9, 2018
    Assignee: RFAXIS, INC.
    Inventor: Qiang Li
  • Patent number: 9231680
    Abstract: A front end circuit for coupling a plurality of antennas to a multi-channel time domain duplex RF transceiver is disclosed. The front end circuit has a first transmit port, a first receive chain primary port, a first receive chain secondary ports, and a first antenna port connectible to a first one of the plurality of antennas. The front end circuit also has a second transmit port, a second receive chain primary port, and a second receive chain secondary port connectible to a second one of the plurality of antennas. A first switch has terminals connected to the first transmit port, the first receive chain primary port, and the second receive chain secondary port, as well as a common terminal that is connected to the first antenna port. Additionally, the front end circuit has a second switch that has terminals connected to the second transmit port, the second receive chain primary port and the first receive chain secondary port, and a common terminal connected to the second antenna port.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: January 5, 2016
    Assignee: RFAXIS, INC.
    Inventor: Oleksandr Gorbachov
  • Patent number: 9143184
    Abstract: A multiport radio frequency (RF) switch circuit is disclosed. The switch circuit includes a first transistor that is connected to a first port, a common antenna port, and a first enable line. The first transistor is selectively activatable in response to a first enable signal applied to the first enable line. There is also a second transistor connected to a second port, the common antenna port, and a second enable line. The second transistor is selectively activatable in response to a second enable signal applied to the second enable line. A first inductor connected to the first port and the second port compensates for parasitic capacitance between the first port and the second port from an inactive one of the transistors.
    Type: Grant
    Filed: October 14, 2011
    Date of Patent: September 22, 2015
    Assignee: RFAXIS, INC.
    Inventors: Oleksandr Gorbachov, Okjune Jeon, Taewon Jung
  • Patent number: 9093967
    Abstract: A power amplifier architecture and front end circuits utilizing the same that connect a transceiver to an antenna are disclosed. The transceiver is configured for a specific operating frequency. An input matching segment is connected to an input port, and an output matching segment is connected to an output port. An amplifier segment includes at least one transistor with a first terminal connected to the input matching segment, a second terminal connected to the output matching segment, and a third terminal connected to a filter with a range of rejection frequencies. The filter is connected in close proximity to a first inductive interconnection tying a junction connected to the third terminal to a ground. A compensator is also connected to the input matching segment and the output matching segment to minimize instability of the filter.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: July 28, 2015
    Assignee: RFAXIS, INC.
    Inventor: Oleksandr Gorbachov
  • Patent number: 9093734
    Abstract: A directional coupler with increased directivity and reduced overall footprint area is disclosed. There is an input port, an output port, a coupled port, and a ballasting port. A primary chain of serially connected inductors is connected to the input port and the output port, while a secondary chain of serially connected inductors is connected to the coupled port and the ballasting port. A first compensation capacitor is connected to the input port and the coupled port, and a second compensation capacitor is connected to the input port and the ballasting port.
    Type: Grant
    Filed: April 11, 2014
    Date of Patent: July 28, 2015
    Assignee: RFAXIS, INC.
    Inventor: Oleksandr Gorbachov
  • Patent number: 9065385
    Abstract: A radio frequency (RF) power amplifier circuit with spur cancellation for GSM/GPRS/EDGE transceivers is disclosed. There is a power amplifier with an RF input, an RF output, and a voltage supply input. Additionally, there is an adjustable DC-DC converter with an input connected to a battery, an output connected to the voltage supply input of the power amplifier with a DC supply voltage signal generated thereby. A spur compensator generates an error control signal responsive to spurs in the DC supply voltage signal. The error control signal is applied to the RF input of the power amplifier.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: June 23, 2015
    Assignee: RFAXIS, INC.
    Inventor: Oleksandr Gorbachov
  • Patent number: 9054653
    Abstract: A power amplifier architecture for connecting a radio frequency (RF) transceiver to an antenna. An input matching circuit is connected to its input port, and an output matching circuit is connected to its output port. An amplifier circuit includes at least one amplifier active device with a first terminal connected to the input matching segment and a second terminal connected to the output matching segment. A first harmonic feedback circuit is connected across the amplifier active device. Voltage components of emissions of one or more harmonic frequencies of a carrier fundamental frequency generated by the amplifier active device is fed back with opposite phase to the first terminal of the amplifier active device. A negative feedback is defined at a level correlated with a gain level of the amplifier active device at the harmonic frequencies of the carrier fundamental frequency. Negative feedback is minimized at the carrier fundamental frequency.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: June 9, 2015
    Assignee: RFAXIS, INC.
    Inventor: Oleksandr Gorbachov
  • Publication number: 20150015339
    Abstract: An RF power amplifier circuit and input power limiter circuits are disclosed. A power detector generates a voltage output proportional to a power level of an input signal. There is a directional coupler with a first port connected to a transmit signal input, a second port connected to the input matching network, and a third port connected to the power detector. A first power amplifier stage with an input is connected to the input matching network and an output is connected to the transmit signal output. A control circuit connected to the power detector generates a gain reduction signal based upon a comparison of the voltage output from the power detector to predefined voltage levels corresponding to specific power levels of the input signal. Overall gain of the RF power amplifier circuit is reduced based upon the gain reduction signal that adjusts the configurations of the circuit components.
    Type: Application
    Filed: July 9, 2014
    Publication date: January 15, 2015
    Applicant: RFAXIS, INC.
    Inventors: OLEKSANDR GORBACHOV, HUAN ZHAO, LISETTE L. ZHANG, LOTHAR MUSIOL, YONGXI QIAN
  • Patent number: 8928428
    Abstract: A directional coupler with increased directivity is disclosed. There is an input port, an output port, a coupled port, and a ballasting port. A first transmission element has a first connection to the input port and a second connection to the output port, and a second transmission element has a first connection to the coupled port and a second connection to the ballasting port. A first compensation capacitor is connected to the input port and the coupled port, and a second compensation capacitor is connected to the input port and the ballasting port.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: January 6, 2015
    Assignee: RFaxis, Inc.
    Inventor: Oleksandr Gorbachov
  • Publication number: 20140335802
    Abstract: A radio frequency switch circuit with improved harmonic suppression and low insertion loss has an antenna port and a plurality of signal ports. A plurality of transistor switch circuits, are connected to a respective one of the plurality of signal ports and to the antenna port. Each of the transistor switch circuits has a transistor, which in an off state, together with a harmonic suppression capacitor and a parallel inductor both connected thereto, define a tank circuit that suppresses RF signals applied to the corresponding transistor switch circuit from a different one of the transistor switch circuits. The harmonic suppression capacitor is tuned to distribute large signal voltage swings in the RF signal amongst parasitic diodes of the transistor.
    Type: Application
    Filed: May 8, 2014
    Publication date: November 13, 2014
    Applicant: RFAXIS, INC.
    Inventors: Huan ZHAO, Qiang LI
  • Publication number: 20140327497
    Abstract: A radio frequency (RF) filter circuit for rejecting one or more spurious components of an input signal has a first resonator circuit including a first capacitor and a first coupled inductor pair of a first inductor and a second inductor, and a second resonator circuit with a second capacitor and a second coupled inductor pair of a third inductor and a fourth inductor. First and second resonator coupling capacitors are connected to the first resonator circuit and the second resonator circuit. A first port and a second port are connected to the first resonator circuit and the second resonator, with the filtered signal of the input signal passed through both the first resonator circuit and the second resonator circuit being output.
    Type: Application
    Filed: May 2, 2014
    Publication date: November 6, 2014
    Applicant: RFAXIS, INC.
    Inventors: Oleksandr Gorbachov, Lisette L. Zhang, Huan Zhao, Lothar Musiol
  • Publication number: 20140327483
    Abstract: An RF power amplifier circuit is disclosed. A driver amplifier stage includes a first set of a plurality of amplifier transistors in a cascode configuration, a driver amplifier stage input, and a driver amplifier stage output. A final amplifier stage includes a second set of a plurality of amplifier transistors in a cascode configuration, a final amplifier stage input connected to the driver amplifier stage output, a final amplifier stage output, and a power supply input. An envelope signal amplifier has an input connectible to an envelope signal source, and an output capacitively coupled to the power supply input. A power converter input is connected to the power supply input to provide supplemental power to the final amplifier stage based on an envelope signal from the envelope signal source that corresponds to an input RF signal.
    Type: Application
    Filed: May 1, 2014
    Publication date: November 6, 2014
    Applicant: RFAXIS, INC.
    Inventor: FLORINEL BALTEANU
  • Publication number: 20140323066
    Abstract: An integrated circuit architecture and circuitry is defined by a die structure with a plurality of exposed conductive pads arranged in a grid of rows and columns. The die structure has a first operating frequency region with a first transmit and receive chain, and a second operating frequency region with a second transmit chain and a second receive chain. There is a shared region of the die structure defined by an overlapping segment of the first operating frequency region and the second operating frequency region with a shared power supply input conductive pad connected to the first transmit chain, the second transmit chain, the first receive chain, and the second receive chain, and a shared power detection output conductive pad connected to the first transmit chain and the second transmit chain.
    Type: Application
    Filed: April 23, 2014
    Publication date: October 30, 2014
    Applicant: RFAXIS, INC.
    Inventors: LISETTE L. ZHANG, OLEKSANDR GORBACHOV
  • Publication number: 20140306778
    Abstract: A directional coupler with increased directivity and reduced overall footprint area is disclosed. There is an input port, an output port, a coupled port, and a ballasting port. A primary chain of serially connected inductors is connected to the input port and the output port, while a secondary chain of serially connected inductors is connected to the coupled port and the ballasting port. A first compensation capacitor is connected to the input port and the coupled port, and a second compensation capacitor is connected to the input port and the ballasting port.
    Type: Application
    Filed: April 11, 2014
    Publication date: October 16, 2014
    Applicant: RFAXIS, INC.
    Inventor: OLEKSANDR GORBACHOV
  • Publication number: 20140197892
    Abstract: A power amplifier architecture for connecting a radio frequency (RF) transceiver to an antenna. An input matching circuit is connected to its input port, and an output matching circuit is connected to its output port. An amplifier circuit includes at least one amplifier active device with a first terminal connected to the input matching segment and a second terminal connected to the output matching segment. A first harmonic feedback circuit is connected across the amplifier active device. Voltage components of emissions of one or more harmonic frequencies of a carrier fundamental frequency generated by the amplifier active device is fed back with opposite phase to the first terminal of the amplifier active device. A negative feedback is defined at a level correlated with a gain level of the amplifier active device at the harmonic frequencies of the carrier fundamental frequency. Negative feedback is minimized at the carrier fundamental frequency.
    Type: Application
    Filed: January 10, 2014
    Publication date: July 17, 2014
    Applicant: RFAXIS, INC.
    Inventor: OLEKSANDR GORBACHOV
  • Publication number: 20140118075
    Abstract: A radio frequency (RF) power amplifier circuit with spur cancellation for GSM/GPRS/EDGE transceivers is disclosed. There is a power amplifier with an RF input, an RF output, and a voltage supply input. Additionally, there is an adjustable DC-DC converter with an input connected to a battery, an output connected to the voltage supply input of the power amplifier with a DC supply voltage signal generated thereby. A spur compensator generates an error control signal responsive to spurs in the DC supply voltage signal. The error control signal is applied to the RF input of the power amplifier.
    Type: Application
    Filed: October 30, 2013
    Publication date: May 1, 2014
    Applicant: RFAXIS, INC.
    Inventor: OLEKSANDR GORBACHOV
  • Patent number: 8649739
    Abstract: A front end circuit for coupling an antenna to a radio frequency (RF) transceiver is disclosed. An antenna port connectible to the antenna is provided, as well as a power amplifier coupled to a signal output of the RF transceiver and a low noise amplifier coupled to the signal input of the RF transceiver. The front end circuit includes a switching network that is connected to the antenna port, the power amplifier, and the low noise amplifier. Additionally, there is at least one resonant circuit and a control circuit coupled to a receive enable line of the transceiver. This resonant circuit defines a parallel resonance with a first resonant resistance in the operating frequency band upon activation in the receive mode. The resonant circuit also defines a substantially high transistor impedance upon deactivation in the transmit mode.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: February 11, 2014
    Assignee: Rfaxis, Inc.
    Inventor: Oleksandr Gorbachov
  • Patent number: 8467738
    Abstract: A radio frequency (RF) front end circuit for connecting an antenna to a transceiver having multiple operating modes is disclosed. The circuit has a first transmit input receptive to signals of a first operating mode and a second operating mode from the transceiver. There is also a second transmit input receptive to signals of a third operating mode from the transceiver. The circuit has a first power amplifier for the first and second operating modes, a second power amplifier for the first operating mode, and a third power amplifier for the second and third operating mode. A first switch network selectively interconnects the first transmit input to a one of the second and third power amplifiers.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: June 18, 2013
    Assignee: RFaxis, Inc.
    Inventor: Oleksandr Gorbachov
  • Patent number: 8417286
    Abstract: A radio frequency communications system with a first operating frequency band and a second operating frequency band is disclosed. There is a first antenna. A transceiver has a first transmission port, a second transmission port, a first reception port, and a second reception port. In a first front end circuit, a first port is coupled to the antenna, and a second port is coupled to the transceiver. The first front end circuit has a first low noise amplifier, a second low noise amplifier, a first power amplifier, and a second power amplifier. A switching circuit connects the first transmission port, the first reception port, the second transmission port, and the second reception port to the second port of the first front end circuit. The antenna is distant from the transceiver, while the first front end circuit is proximal to the antenna. The first switching circuit is proximal to the transceiver.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: April 9, 2013
    Assignee: RFaxis, Inc.
    Inventors: Oleksandr Gorbachov, Ping Peng
  • Patent number: 8374557
    Abstract: A front end circuit for selectively coupling a first antenna and a second antenna to a transmit chain and a receive chain of a radio frequency (RF) transceiver is disclosed. There is a first power amplifier having an input connectible to the transmit chain of the RF transceiver, a first low noise amplifier having an output connectible to the receive chain of the RF transceiver, and a second low noise amplifier with an input connectible to the second antenna, as well as an output connectible to the receive chain of the RF transceiver. A first matching and switch network is connected to the first antenna, the output of the first power amplifier, and the input of the first low noise amplifier. Transmit signals from the first power amplifier and receive signals from the first antenna are selectively passed to the first antenna and the first low noise amplifier.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: February 12, 2013
    Assignee: RFAXIS, Inc.
    Inventor: Oleksandr Gorbachov