Abstract:
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.
Abstract:
A compact integrated power amplifier is described herein. In an exemplary design, an apparatus includes (i) an integrated circuit (IC) die having at least one transistor for a power amplifier and (ii) an IC package having a load inductor for the power amplifier. The IC die is mounted on the IC package with the transistor(s) located over the load inductor. In an exemplary design, the IC die includes a transistor manifold that is placed over the load inductor on the IC package. The transistor(s) are fabricated in the transistor manifold, have a drain connection in the center of the transistor manifold, and have source connections on two sides of the transistor manifold. The IC die and the IC package may include one or more additional power amplifiers. The transistor(s) for each power amplifier may be located over the load inductor for that power amplifier.
Abstract:
Exemplary embodiments disclosed are directed to power and impedance measurement circuits that may be used to measure power and/or impedance are described. A measurement circuit may include a sensor and a computation unit. The sensor may sense (i) a first voltage signal across a series circuit coupled to a load to obtain a first sensed signal and (ii) a second voltage signal at a designated end of the series circuit to obtain a second sensed signal. The sensor may mix (i) a first version of the first sensed signal with a first version of the second sensed signal to obtain a first sensor output and (ii) a second version of the first sensed signal with a second version of the second sensed signal to obtain a second sensor output. The computation unit may determine the impedance and/or delivered power at the designated end of the series circuit based on the sensor outputs.
Abstract:
An amplifier circuit includes a power amplifier biased for saturated mode operation, and a contrallable current source to provide current to the power amplifer. The controllable current source effects desired amplitude modulation of the output signal from the power amplifier by modulating the supply current it provides responsive to an amplitude information signal.
Abstract:
Multiple low noise amplifiers (LNAs) with combined outputs are disclosed. In an exemplary design, an apparatus includes a front-end module and an integrated circuit (IC). The front-end module includes a plurality of LNAs having outputs that are combined. The IC includes receive circuits coupled to the plurality of LNAs via a single interconnection. In an exemplary design, each of the plurality of LNAs may be enabled or disabled via a respective control signal for that LNA. The front-end module may also include receive filters coupled to the plurality of LNAs and a switchplexer coupled to the receive filters. The front-end module may further include at least one power amplifier, and the IC may further include transmit circuits coupled to the at least one power amplifier.
Abstract:
This disclosure provides systems, methods and apparatus for combining devices deposited on a first substrate, with integrated circuits formed on a second substrate such as a semiconducting substrate or a glass substrate. The first substrate may be a glass substrate. The first substrate may include conductive vias. A power combiner circuit may be deposited on a first side of the first substrate. The power combiner circuit may include passive devices deposited on at least the first side of the first substrate. The integrated circuit may include a power amplifier circuit disposed on and configured for electrical connection with the power combiner circuit, to form a power amplification system. The conductive vias may include thermal vias configured for conducting heat from the power amplification system and/or interconnect vias configured for electrical connection between the power amplification system and a conductor on a second side of the first substrate.
Abstract:
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.
Abstract:
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.
Abstract:
A multi-mode multi-band power amplifier (PA) module is described. In an exemplary design, the PA module includes multiple power amplifiers, multiple matching circuits, and a set of switches. Each power amplifier provides power amplification for its input signal when selected. Each matching circuit provides impedance matching and filtering for its power amplifier and provides a respective output signal. The switches configure the power amplifiers to support multiple modes, with each mode being for a particular radio technology. Each power amplifier supports at least two modes. The PA module may further include a driver amplifier and an additional matching circuit. The driver amplifier amplifies an input signal and provides an amplified signal to the power amplifiers. The additional matching circuit combines the outputs of other matching circuits and provides an output signal with higher output power. The driver amplifier and the power amplifiers can support multiple output power levels.
Abstract:
Switchable voltage level supplies for circuitry in a multi-mode communications chipset are disclosed. In an embodiment, a first voltage level is supplied to TX circuitry operating in a first mode having a first set of linearity and/or noise requirements. A second voltage level lower than the first voltage level is supplied to TX circuitry operating in a second mode having a second set of linearity and/or noise requirements looser than the first set of requirements. The first mode may be operation according to the GSM standard, and the second mode may be operation according to the W-CDMA standard.