| Patent application number | Description | Published |
|---|
| 20110018632 | POWER AMPLIFIER WITH SWITCHED OUTPUT MATCHING FOR MULTI-MODE OPERATION - Exemplary embodiments are directed to a transmitter with a power amplifier and a switched output matching circuit implementing a plurality of output paths for a plurality of operating modes is described. The power amplifier receives an input RF signal and provides an amplified RF signal. An output matching network performs impedance transformation from low impedance at the power amplifier output to higher impedance at the matching network output. The plurality of output paths are coupled to the output matching network. Each output path provides a different target output impedance for the power amplifier and routes the amplified RF signal from the power amplifier to an antenna when that output path is selected. Each output path may include a matching network coupled in series with a switch. The matching network provides the target output impedance for the power amplifier when the output path is selected. The switch couples or decouples the output path to/from the power amplifier. | 01-27-2011 |
| 20110025422 | POWER AMPLIFIER BIAS CURRENT MONITOR AND CONTROL MECHANISM - Techniques for monitoring and controlling bias current of amplifiers are described. In an exemplary design, an apparatus may include an amplifier and a bias circuit. The amplifier may include at least one transistor coupled to an inductor. The bias circuit may generate at least one bias voltage for the at least one transistor in the amplifier to obtain a target bias current for the amplifier. The bias circuit may generate the at least one bias voltage based on a voltage across the inductor in the amplifier, or a current through a current mirror formed with one of the at least one transistor in the amplifier, or a gate-to-source voltage of one of the at least one transistor in the amplifier, or a voltage in a replica circuit replicating the amplifier, or a current applied to the amplifier with a switched mode power supply disabled. | 02-03-2011 |
| 20110032035 | AMPLIFIER MODULE WITH MULTIPLE OPERATING MODES - An amplifier module with multiple operating modes is described. In an exemplary design, the amplifier module includes an amplifier (e.g., a power amplifier), a switch, and an output circuit. The amplifier receives and amplifies an input signal and provides an amplified signal in a first mode. The switch is coupled to the output of the amplifier and bypasses the amplifier and provides a bypass signal in a second mode. The output circuit is coupled to the amplifier and the switch. The output circuit performs output impedance matching for the amplifier in the first mode. The output circuit also (i) receives the amplified signal and provides an output signal in the first mode and (ii) receives the bypass signal and provides the output signal in the second mode. The amplifier is enabled in the first mode and disabled in the second mode. | 02-10-2011 |
| 20110037516 | MULTI-STAGE IMPEDANCE MATCHING - Exemplary techniques for performing impedance matching are described. In an exemplary embodiment, the apparatus may include an amplifier (e.g., a power amplifier) coupled to first and second matching circuits. The first matching circuit may include multiple stages coupled to a first node and may provide input impedance matching for the amplifier. The second matching circuit may include multiple stages coupled to a second node and may provide output impedance matching for the amplifier. At least one switch may be coupled between the first and second nodes and may bypass or select the amplifier. The first and second nodes may have a common impedance. The apparatus may further include a second amplifier coupled in parallel with the amplifier and further to the matching circuits. The second matching circuit may include a first input stage coupled to the amplifier, a second input stage coupled to the second amplifier, and a second stage coupled to the two input stages via switches. | 02-17-2011 |
| 20110043285 | DIGITAL TUNABLE INTER-STAGE MATCHING CIRCUIT - A tunable inter-stage matching circuit that can improve performance is described. In an exemplary design, an apparatus includes a first active circuit (e.g., a driver amplifier), a second active circuit (e.g., a power amplifier), and a tunable inter-stage matching circuit coupled between the first and second active circuits. The tunable inter-stage matching circuit includes a tunable capacitor that can be varied in discrete steps to adjust impedance matching between the first and second active circuits. In an exemplary design, the tunable capacitor includes (i) a plurality of capacitors coupled in parallel and (ii) a plurality of switches coupled to the plurality of capacitors, one switch for each capacitor. Each switch may be turned on to select an associated capacitor or turned off to unselect the associated capacitor. The tunable capacitor may further include a fixed capacitor coupled in parallel with the plurality of capacitors. | 02-24-2011 |
| 20110043956 | PROTECTION CIRCUIT FOR POWER AMPLIFIER - Techniques for protecting a power amplifier (PA) are described. In an exemplary design, an apparatus includes (i) a PA module to amplify an input RF signal and provide an output RF signal and (ii) a protection circuit to control a transmitter gain to protect the PA module against high peak voltage. In an exemplary design, the protection circuit includes a set of comparators to quantize an analog input signal and provide digital comparator output signals used to adjust the transmitter gain. In another exemplary design, the protection circuit reduces and increases the transmitter gain with hysteresis. In yet another exemplary design, the protection circuit has faster response to rising amplitude than falling amplitude of the output RF signal. The hysteresis and/or the different rise and fall responses may allow the protection circuit to avoid toggling the transmitter gain under severe load mismatch and to handle time-varying envelope due to amplitude modulation. | 02-24-2011 |
| 20110050285 | HIGH LINEAR FAST PEAK DETECTOR - A high linear fast peak detector having a variable bias current and/or a variable bias voltage is described. In an exemplary design, the peak detector includes a transistor, a variable current source, a capacitor, and a feedback circuit. The transistor receives the input signal and provides a source current. The variable current source receives the input signal, provides high bias current when the input signal is low, and provides low bias current when the input signal is high. The capacitor is charged by the source current when the input signal is high and is discharged by the high bias current when the input signal is low. The feedback circuit receives a detected signal from the capacitor and provides higher bias voltage for the transistor when the input signal is high, which results in higher source current from the transistor. | 03-03-2011 |
| 20110095826 | ADAPTIVE PARAMETRIC POWER AMPLIFIER PROTECTION CIRCUIT - A device including a gain control element coupled prior to or within a radio frequency (RF) power amplifier (PA) with an adaptive parametric PA protection circuit is described. In an exemplary embodiment, the device includes a gain control element coupled prior to a radio frequency power amplifier with a power stage with corresponding transistor breakdown threshold values, having an adaptive parametric PA protection circuit configured to receive at least one power stage drain-source voltage parameter value, at least one power stage drain-gate voltage parameter value, and at least one power stage drain-source current parameter value, and including an adaptive parametric PA protection circuit having a first section for processing the parameter values and a second section for generating a gain correction signal to adjust the gain control element with optimal power added efficiency (PAE) for the power stage within the corresponding transistor breakdown threshold values. | 04-28-2011 |
| 20110128084 | METHODS AND APPARATUS FOR INDUCTORS WITH INTEGRATED PASSIVE AND ACTIVE ELEMENTS - An integrated circuit is described. The integrated circuit includes an inductor that has a large empty area in the center of the inductor. The integrated circuit also includes additional circuitry. The additional circuitry is located within the large empty area in the center of the inductor. The additional circuitry may include a capacitor bank, transistors, electrostatic discharge (ESD) protection circuitry and other miscellaneous passive or active circuits. | 06-02-2011 |
