Psemi Corporation

Murata Manufacturing Co., Ltd.

Miles Sanner

Emre Ayranci

Phanindra Yerramilli

Kashish Pal

Tero Tapio Ranta

Chih-Chieh Cheng

Kevin Roberts

James Francis McElwee

Mengsheng Rui

Ke Li

Parvez Daruwalla

Jubaid Qayyum

Edward Nicholas Comfoltey

Jing Li

Steve Gao

Anant Rungta

Vijay Katta

A receiver front end amplifier capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs) is disclosed herein. A cascode having a 'common source' configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. Further switches used for switching degeneration inductors, gate capacitors, and gate to ground capacitors for each leg can be used to further improve the matching performance of the invention.

Source switched split LNA

Circuits and methods for an amplifier (particularly LNAs) that achieve wideband output impedance matching and high gain while simultaneously rejecting out-of-band (OOB) harmonic frequencies. Some embodiments allow multiple modes of operation to allow selection of gain versus linearity characteristics. One aspect of the present invention is improvement of the linearity and sensitivity of a whole RF 'front end' (RFFE) receiver chain by suppressing OOB gain within an LNA component at higher order harmonic frequencies. Another aspect of the present invention are new wideband and ultra-wideband LNA load circuits that, while achieving high frequency OOB rejection, maintain in-band high gain and wideband output impedance matching at the same time. Yet another aspect of the present invention are new ultra-wideband LNA output impedance matching circuits.

Extended impedance matching wideband LNA architectures

Circuits and methods for a radio frequency amplifier, such as an LNA, that include a wideband coupled input impedance matching network. One embodiment includes a first inductor coupled between a first terminal and a first node, the first terminal couplable to a degeneration terminal of an amplifier core; a second inductor coupled between a second terminal and either the first node or a second node, the second terminal couplable to an input terminal of the amplifier core; a third inductor coupled between the first node and a third terminal, the third terminal couplable to a reference potential; and, in a variant embodiment, a fourth inductor coupled between the second node and a fourth terminal, the fourth terminal couplable to the reference potential; wherein the first inductor and the second inductor are mutually coupled. Some embodiments allow multiple modes to allow tradeoffs of gain versus linearity and NF characteristics.

Wideband coupled input impedance matching LNA architecture

A front end module (FEM) integrated circuit (IC) architecture that uses the same LNA in each of several frequency bands extending over a wide frequency range. In some embodiments, switched impedance circuits distributed throughout the front end circuit allow selection of the frequency response and impedances that are optimized for particular performance parameters targeted for a desired device characteristic. Such switched impedance circuits tune the output and input impedance match and adjust the gain of the LNA for specific operating frequencies and gain targets. In addition, adjustments to the bias of the LNA can be used to optimize performance trade-offs between the total direct current (DC) power dissipated versus radio frequency (RF) performance. By selecting appropriate impedances throughout the circuit using switched impedance circuits, the LNA can be selectively tuned to operate optimally at a selected bias for operation within selected frequency bands.

Programmable optimized band switching LNA

A flexible multi-path RF adaptive tuning network switch architecture that counteracts impedance mismatch conditions arising from various combinations of coupled RF band filters, particularly in a Carrier Aggregation-based (CA) radio system. In one version, a digitally-controlled tunable matching network is coupled to a multi-path RF switch in order to provide adaptive impedance matching for various combinations of RF band filters. Optionally, some or all RF band filters include an associated digitally-controlled filter pre-match network to further improve impedance matching. In a second version, some or all RF band filters coupled to a multi-path RF switch include a digitally-controlled phase matching network to provide necessary per-band impedance matching. Optionally, a digitally-controlled tunable matching network may be included on the common port of the multi-path RF switch to provide additional impedance matching capability. In a third version, CA direct mapped adaptive tuning networks include filter tuning blocks for selected lower frequency bands.

Adaptive tuning networks with direct mapped multiple channel filter tuning

An amplifier circuit configuration capable of processing non-contiguous intra-band carrier aggregate (CA) signals using amplifiers is disclosed herein. In some cases, each of a plurality of amplifiers is an amplifier configured as a cascode (i.e., a two-stage amplifier having two transistors, the first configured as a 'common source' input transistor, e.g., input field effect transistor (FET), and the second configured in a “common gate” configuration as a cascode output transistor, (e.g. cascode output FET). In other embodiments, the amplifier may have additional transistors (i.e., more than two stages and/or stacked transistors). The amplifier circuit configuration can be operated in either single mode or split mode. A switchable coupling is placed between the drain of the input FETs of each amplifier within the amplifier circuit configuration. During split mode, the coupling is added to the circuit to allow some of the signal present at the drain of each input FET to be coupled to the drain of the other input FET.

Drain switched split amplifier with capacitor switching for noise figure and isolation improvement in split mode

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a 'common source' configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the gof the input stage of the amplifier, thus improving the noise figure of the amplifier.

Drain sharing split LNA

Methods and devices for realizing RF processing paths associated to different frequency bands are presented. According to one aspect, the RF processing paths are provided by a hybrid input LNA RF frontend that includes RF processing paths that are dedicated to specific frequency bands and RF processing paths that are shared between several frequency bands. Sharing of the RF processing paths is provided by an input combiner network and/or a multi-input cascode amplifier that includes a cascode transistor that is coupled to at least two input transistors. Further presented in a toolkit that includes circuit blocks that can be used in specific combinations to customize the RF processing paths to achieve specific performance or cost optimization. A decision tree based on performance and cost priorities assigned to each of the frequency bands is used to provide the specific combinations.

Hybrid input LNA RF frontend architecture

A receiver topology for supporting various combinations of interband carrier aggregation (CA) signals, intraband non-contiguous CA and non-CA signals having different combinations of signals aggregated therein.

RFFE LNA topology supporting both noncontiguous intraband carrier aggregation and interband carrier aggregation

Methods and devices addressing design of wideband LNAs with gain modes are disclosed. The disclosed teachings can be used to reconfigure RF receiver front-end to operate in various applications imposing stringent and conflicting requirements. Wideband and narrowband input and output matching with gain modes using a combination of the same hardware and a switching network are also disclosed. The described methods and devices also address carrier aggregation requirements and provide solutions that can be used both in single-mode and split-mode operations.

Configurable wideband split LNA

A low noise amplifier (LNA) with configurable feedback that includes a filter circuit for improved stability is presented. The filter circuit includes an L-C tank. The filter circuit further includes a resistor in parallel with the L-C tank. The filter circuit is tunable/adjustable/programmable. The filter circuit further includes a capacitor selectively arranged in parallel with the L-C tank. The filter circuit is coupled to an input of the LNA via a series resistor. The filter circuit is coupled between the input and an output of the LNA via one or more switches. The LNA includes a first stage with a common-source transistor and a common-gate transistor. The LNA further includes a wideband feedback circuit coupled between the input and output of the first stage. The LNA includes a source-follower circuit. The source follower circuit is configurable as a second stage, or a feedback circuit, coupled to the filter circuit.

LNA architecture with configurable feedback filtering

Methods and devices for reducing DC current consumption of a multi-stage LNA amplifier. According to one aspect, first and second amplification stages are stacked to provide a common conduction path of a DC current. The first stage includes a common-source amplifier, the second stage includes a common-drain amplifier. Coupling between the two stages is provided by series connection of load inductors of the respective stages and a capacitor coupled at a common node between the inductors. According to another aspect, a current splitter circuit is used to split a current to the first stage according to two separate conduction paths, one common path to the two stages, and another separate from the second stage. According to yet another aspect, the current splitter circuit includes a feedback loop that controls the splitting of the current so to maintain a constant current through the common path.

Stacked multi-stage programmable LNA architecture

Methods and circuital arrangements for turning OFF branches of a multi-branch cascode amplifier are presented. First and second switching arrangements coupled to a branch allow turning OFF the branch while protecting transistors of the branch from a supply voltage that may be greater than a tolerable voltage of the transistors. The first switching arrangement includes a transistor-based switch that is in series connection with the transistors of the branch. The first switching arrangement drops the supply voltage during the OFF state of the branch and provides a conduction path for a current through the branch during the ON state of the branch. A resistor and a shunting switch are coupled to a gate of the transistor-based switch to reduce parasitic coupling effects of the transistor-based switch upon an RF signal coupled to the branch during the ON state and OFF state of the branch.

Dual voltage switched branch LNA architecture

A multi-gain LNA with inductive source degeneration is presented. The inductive source degeneration is provided via a tunable degeneration network that includes an inductor in parallel with one or more switchable shunting networks. Each shunting network includes a shunting capacitor that can selectively be coupled in parallel to the inductor. A capacitance of the shunting capacitor is calculated so that a combined impedance of the inductor and the shunting capacitor at a narrowband frequency of operation is effectively an inductance. The inductance is calculated according to a desired gain of the LNA. According to one aspect, the switchable shunting network includes a resistor in series connection with the shunting capacitor to provide broadband frequency response stability of the tunable degeneration network. According to another aspect, the LNA includes a plurality of selectable branches to further control gain of the LNA.

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San Diego, CA, United States of America

Miles Sanner