Patents Assigned to RF Micro Devices (Cayman Islands), Ltd.
  • Patent number: 9294046
    Abstract: Circuitry, which includes a package interface, an RF amplification circuit, and a closed-loop phase linearization circuit, is disclosed. The package interface receives an RF signal and provides an amplified RF signal. The RF amplification circuit amplifies the RF signal to generate the amplified RF signal, such that an intermediate RF signal is generated during amplification of the RF signal. The closed-loop phase linearization circuit endogenously establishes a target phase of the amplified RF signal using the RF signal. Further, the closed-loop phase linearization circuit applies a phase-shift to the intermediate RF signal based on a difference between the target phase and a measured phase, which is representative of a phase of the amplified RF signal, wherein the phase-shift reduces phase distortion in the amplified RF signal.
    Type: Grant
    Filed: March 17, 2014
    Date of Patent: March 22, 2016
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Dirk Robert Walter Leipold
  • Patent number: 9294042
    Abstract: A power amplifier system with supply modulation mitigation circuitry and methods is disclosed. The power amplifier system includes a regulator having an unregulated input and a regulated output along with a power amplifier having a supply input for receiving a supply current from the regulated output and having a signal input and a signal output that comprise a main signal path. The supply modulation mitigation circuitry is adapted to sense a supply modulation signal output from the regulator, generate a cancellation signal that is a scaled inverse of the supply modulation signal, and inject the cancellation signal into a node within the power amplifier system to sum the supply modulation signal and cancellation signal together to reduce the supply modulation signal from within the main signal path.
    Type: Grant
    Filed: March 17, 2014
    Date of Patent: March 22, 2016
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim
  • Patent number: 8890616
    Abstract: Power amplifier (PA) systems are typically comprised of a signal path integrated circuit (IC) and a power control IC. Advanced CMOS technologies may allow smart integration of such ICs into a single IC and provide an opportunity to improve performance and cost. Specifically, the radio frequency (RF) signal path is designed to enable local biasing of the gain stages that comprise the RF signal path. By using current-mode biasing instead of the prior art voltage-mode biasing significant area reduction is achieved as well as better isolation between the stages which reduces noise, and improves stability.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: November 18, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim
  • Patent number: 8843083
    Abstract: Transmit modules typically constitute passive matching circuitry, harmonic trap filters and an antenna switch to provide isolation between the transmit bands as well as between transmit and receive functions. In complementary metal-oxide semiconductor (CMOS) processes the switch function is difficult to implement as a large voltage swing may result in breakdown of the MOS oxide, drain diode, source diode as well as substrate diodes. Therefore a switching function is provided at a node that has low impedance during transmit that limits the voltage swing that the MOS switches experience. The approach is particularly useful, but not limited to, half duplex transmissions such as those used in global system for mobile (GSM) communication, enhanced data for GSM Evolution (EDGE), and time division synchronous code division multiple access (TDSCDMA).
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: September 23, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventor: Malcolm Smith
  • Publication number: 20140266459
    Abstract: Circuitry, which includes a package interface, an RF amplification circuit, and a closed-loop phase linearization circuit, is disclosed. The package interface receives an RF signal and provides an amplified RF signal. The RF amplification circuit amplifies the RF signal to generate the amplified RF signal, such that an intermediate RF signal is generated during amplification of the RF signal. The closed-loop phase linearization circuit endogenously establishes a target phase of the amplified RF signal using the RF signal. Further, the closed-loop phase linearization circuit applies a phase-shift to the intermediate RF signal based on a difference between the target phase and a measured phase, which is representative of a phase of the amplified RF signal, wherein the phase-shift reduces phase distortion in the amplified RF signal.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Dirk Robert Walter Leipold
  • Publication number: 20140266452
    Abstract: A radio frequency (RF) amplification circuit and a closed-loop amplitude linearization circuit are disclosed. The RF amplification circuit amplifies an RF signal to generate an amplified RF signal. The RF amplification circuit and the closed-loop amplitude linearization circuit form a fast control loop and a slow control loop. The slow control loop estimates a total radiated power (TRP) from the RF amplification circuit to create a TRP estimate using a representation of the amplified RF signal, and controls a fast loop gain of the fast control loop based on the TRP estimate. The fast control loop applies a gain adjustment to the RF amplification circuit based on the fast loop gain and a difference between a target reference amplitude and a measured feedback amplitude. The gain adjustment controls amplitude distortion in the RF amplification circuit. The fast loop gain controls TRP-drift in the RF amplification circuit.
    Type: Application
    Filed: March 18, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, Dirk Robert Walter Leipold, George Maxim
  • Publication number: 20140266444
    Abstract: A power amplifier system with supply modulation mitigation circuitry and methods is disclosed. The power amplifier system includes a regulator having an unregulated input and a regulated output along with a power amplifier having a supply input for receiving a supply current from the regulated output and having a signal input and a signal output that comprise a main signal path. The supply modulation mitigation circuitry is adapted to sense a supply modulation signal output from the regulator, generate a cancellation signal that is a scaled inverse of the supply modulation signal, and inject the cancellation signal into a node within the power amplifier system to sum the supply modulation signal and cancellation signal together to reduce the supply modulation signal from within the main signal path.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim
  • Publication number: 20140266451
    Abstract: Circuitry, which includes a package interface, a radio frequency (RF) amplification circuit, and a closed-loop gain linearization circuit. The package interface receives an RF signal and provides an amplified RF signal. The RF amplification circuit amplifies the RF signal in accordance with a gain of the RF amplification circuit so as to generate the amplified RF signal. In one embodiment, the closed-loop gain linearization circuit is configured to endogenously establish a target gain magnitude using the RF signal and linearize the gain of the RF amplification circuit in accordance with the target gain magnitude. By endogenously establishing the target gain magnitude using the RF signal, the closed-loop gain linearization circuit can provide linearity with greater independence from external control circuitry.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim
  • Publication number: 20140266457
    Abstract: Embodiments of a radio frequency (RF) amplification device having an RF amplification circuit and an amplifier control circuit operably associated with the RF amplification circuit are disclosed. The RF amplification circuit is configured to amplify an RF signal in accordance with a transfer function. The amplifier control circuit includes a closed-loop linearization circuit and a calibration circuit. The closed-loop linearization circuit is configured to be activated so that the transfer function defines a closed-loop response and inactive so that the transfer function defines an open-loop response. For example, the closed-loop linearization circuit may become inactive at small-signal power levels. Accordingly, the amplifier control circuit also includes a calibration circuit configured to reduce a difference between the open-loop response and the closed-loop response of the transfer function.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Dirk Robert Walter Leipold
  • Publication number: 20140266458
    Abstract: The disclosure provides a communication circuit including an amplification circuit, a replicator circuit, and a correction circuit. Specifically, the amplification circuit generates an amplified signal. The replicator circuit emulates the amplification circuit and generates a replicated signal that approximates the amplified signal. The replicated signal is used by the correction circuit to generate control signals for controlling the amplification circuit.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, Dirk Robert Walter Leipold, George Maxim
  • Patent number: 8766724
    Abstract: The apparatus and method thereof accurately sense and convert a radio frequency (RF) current signal to direct current (DC) independent of process variation and temperature, and without requiring high speed, high voltage amplifiers for its operation. The apparatus comprises an AC coupled circuit that couples the RF signal from the main device to a sense device with an N:M ratio, a low pass filter system that extracts the DC content of the RF current signal, and a negative feedback loop that forces the DC content of the main device and the sensed device to be equal. Exemplary embodiments include a current sensor that provides feedback to protect an RF power amplifier from over-current condition, and a RF power detection and control in a RF power amplifier (PA) that multiplies the sensed output current by the sensed output voltage to be used as a feedback to control the PA's bias.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: July 1, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Daniel Ho, Malcolm Smith
  • Patent number: 8749309
    Abstract: A gate power control technique for a power amplifier (PA) provides practical improved efficiency at backed-off power levels. It can be applied to the main gate of the output stage of the PA, the cascode gate, or any combination thereof. Both voltage mode and current mode signal processing may be used. The gate power control can be implemented in both open-loop and closed-loop using AC and DC coupled drivers and output stages. It may further use one or more control ports in the radio frequency (RF) signal path.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: June 10, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Daniel Ho, Stephen Franck, Ying Shi, Baker Scott
  • Patent number: 8731490
    Abstract: In transmitter modules or power amplifier (PA) modules there is at least a possible path for a second and even a third harmonic of a low band to crossover unfiltered into the high band path and reach the antenna and hence cross band isolation is necessary. Forward isolation is necessary in order to limit the input crossing over the PAs into the antenna port. According to the methods and the circuits such cross band isolation and forward isolation is improved by detuning the filter and matching network at the output of the PA. The circuit comprises a trap at the harmonic frequencies of the low band thereby at least reducing the impacts of the cross band and forward isolation.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: May 20, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Malcolm Smith, Ying Shi
  • Publication number: 20140030990
    Abstract: In transmitter modules or power amplifier (PA) modules there is at least a possible path for a second and even a third harmonic of a low band to crossover unfiltered into the high band path and reach the antenna and hence cross band isolation is necessary. Forward isolation is necessary in order to limit the input crossing over the PAs into the antenna port. According to the methods and the circuits such cross band isolation and forward isolation is improved by detuning the filter and matching network at the output of the PA. The circuit comprises a trap at the harmonic frequencies of the low band thereby at least reducing the impacts of the cross band and forward isolation.
    Type: Application
    Filed: October 2, 2012
    Publication date: January 30, 2014
    Applicant: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Malcolm Smith, Ying Shi
  • Patent number: 8629725
    Abstract: Power amplifier (PA), regardless of the process used for the manufacturing of its devices, suffers from a nonlinear output capacitance that has significant impact on various aspects of the PA performance. This output capacitance is dependent on the large output voltage swing. Accordingly a compensation capacitance is added at the output of the PA that has a behavior that is inverse respective of the output voltage of that of the output capacitance of the PA. Connecting the compensation capacitor in parallel to the PA output capacitance, results in a total capacitance that is the sum of the output capacitance and its compensation capacitance. The total output capacitance is therefore essentially stable throughout the output voltage swing.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: January 14, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Chu Hsiung Ho, Stephen Franck, Tom Biedka
  • Patent number: 8624678
    Abstract: A power amplifier (PA) using switched-bulk biasing to minimize the risk of output stage snapback effect is disclosed. An adaptive biasing of the output stage prevents device breakdown while accommodating large voltage swings. These protection techniques can be applied to all types of cascode configurations of a PA, including single-ended, differential, quadrature, segmented and any combination thereto.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: January 7, 2014
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Stephen Franck
  • Patent number: 8604873
    Abstract: Achievement of robust stability of a power amplifier (PA) that allows the sharing of the ground between the driver stages and the output stage is shown. A controlled amount of negative feedback is used to neutralize the local positive feedback that results from the driver-to-output stage ground sharing in the signal path, for example, a radio frequency (RF) signal path. The solution keeps a strong drive and a good performance of the PA. Exemplary embodiments are shown for the PA positive feedback neutralization. A first embodiment uses a ground signal divider while another embodiment uses a ground signal divider weighting technique.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: December 10, 2013
    Assignee: RF Micro Devices (Cayman Islands), Ltd.
    Inventors: Baker Scott, George Maxim, Stephen Franck, Chu Hsiung Ho