Abstract: An apparatus is disclosed for mixing signals. In example aspects, the apparatus includes a mixer circuit having multiple local oscillator nodes, a first node corresponding to a first frequency, and multiple second nodes corresponding to a second frequency. The mixer circuit includes multiple capacitors coupled between the multiple local oscillator nodes and the multiple second nodes. The mixer circuit has multiple switches including a first switch, a second switch, a third switch, and a fourth switch. The multiple switches are coupled between the multiple capacitors and the multiple second nodes. The first switch and the second switch are coupled between the multiple capacitors and the first node. The first switch and the second switch are disposed between the fourth switch and the third switch.

Abstract: A frequency synthesizer system may include a first voltage-controlled oscillator (VCO) circuit, a second VCO circuit, and multiplexing circuitry. The multiplexing circuitry may be configured to select either the output of the first VCO circuit or the output of the second VCO circuit in response to a mode selection signal.

Abstract: An apparatus includes a low noise amplifier (LNA) multiplexer configured to receive a plurality of radio frequency (RF) signals at a plurality of input terminals and to combine the plurality of RF signals into a combined RF signal that is output at an output terminal. The LNA multiplexer includes a plurality of input signal paths, and each input signal path is coupleable to a respective input terminal of the plurality of input terminals and is configured to receive a respective RF signal of the plurality of RF signals. The apparatus further includes an LNA demultiplexer configured to receive the combined RF signal at an input port coupled to the output terminal and to distribute the combined RF signal to a plurality of output ports, each output port of the plurality of output ports configured to output the combined RF signal to a respective downconverter of a plurality of downconverters.

Abstract: Certain aspects of the present disclosure provide multi-way diversity receivers with multiple synthesizers. Such a multi-way diversity receiver may be implemented in a carrier aggregation (CA) transceiver. One example wireless reception diversity circuit generally includes three or more receive paths for processing received signals and two or more frequency synthesizing circuits configured to generate local oscillating signals to downconvert the received signals. Each of the frequency synthesizing circuits is shared by at most two of the receive paths, and each pair of the frequency synthesizing circuits may generate a pair of local oscillating signals having the same frequency.

Abstract: An apparatus includes a low noise amplifier (LNA) multiplexer configured to receive a plurality of radio frequency (RF) signals at a plurality of input terminals and to combine the plurality of RF signals into a combined RF signal that is output at an output terminal. The LNA multiplexer includes a plurality of input signal paths, and each input signal path is coupleable to a respective input terminal of the plurality of input terminals and is configured to receive a respective RF signal of the plurality of RF signals. The apparatus further includes an LNA demultiplexer configured to receive the combined RF signal at an input port coupled to the output terminal and to distribute the combined RF signal to a plurality of output ports, each output port of the plurality of output ports configured to output the combined RF signal to a respective downconverter of a plurality of downconverters.

Abstract: An apparatus includes an amplifier and a first inductor coupled to an input of the amplifier. The apparatus also includes a second inductor that is inductively coupled to the first inductor and that couples the amplifier to a first supply node. The apparatus further includes a third inductor that is inductively coupled to the first inductor and to the second inductor and that couples the amplifier to a second supply node.

Abstract: Certain aspects of the present disclosure provide multi-way diversity receivers with multiple synthesizers. Such a multi-way diversity receiver may be implemented in a carrier aggregation (CA) transceiver. One example wireless reception diversity circuit generally includes three or more receive paths for processing received signals and two or more frequency synthesizing circuits configured to generate local oscillating signals to downconvert the received signals. Each of the frequency synthesizing circuits is shared by at most two of the receive paths, and each pair of the frequency synthesizing circuits may generate a pair of local oscillating signals having the same frequency.

Abstract: Multiplex modules for use in carrier aggregation receivers are disclosed. In an exemplary embodiment, an apparatus includes an LNA multiplexer configured to receive a plurality of RF signals at a plurality of input terminals and to combine the RF signals into a combined RF signal that is output from an output terminal. The apparatus also includes an LNA demultiplexer configured to receive the combined RF signal at an input port that is connected to the output terminal and to distribute the combined RF signal to a plurality of output ports.

Abstract: An apparatus including: a plurality of amplifiers having a plurality of output ports, respectively, the plurality of amplifiers configured to amplify radio frequency (RF) signals received from at least one antenna; a plurality of demodulators configured to receive the amplified RF signals at a plurality of input ports, respectively, the plurality of demodulators configured to downconvert the received RF signals; and a plurality of switches configured to couple selected output ports of the plurality of amplifiers to selected input ports of the plurality of demodulators, wherein each switch of the plurality of switches is configured such that at least one of the plurality of output ports of the plurality of amplifiers is selectively coupled to any of multiple input ports of the plurality of input ports of the plurality of demodulators.

Abstract: Certain aspects of the present disclosure provide multi-way diversity receivers with multiple synthesizers. Such a multi-way diversity receiver may be implemented in a carrier aggregation (CA) transceiver. One example wireless reception diversity circuit generally includes three or more receive paths for processing received signals and two or more frequency synthesizing circuits configured to generate local oscillating signals to downconvert the received signals. Each of the frequency synthesizing circuits is shared by at most two of the receive paths, and each pair of the frequency synthesizing circuits may generate a pair of local oscillating signals having the same frequency.

Abstract: Wireless receivers are configured to support carrier aggregation. A device may include at least one low-noise amplifier (LNA). The device may also include a first input path configured to convey a first signal to a first input of the at least one LNA(s), and a second input path configured to convey a second signal to a second input of the LNA(s). Further, the device may include a transformer configured to inductively couple the first input path to the second input path.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for dynamically adjusting a voltage-controlled oscillator (VCO) frequency, a local oscillator (LO) divider ratio, and/or a receive path when adding or discontinuing reception of a component carrier (CC) in a carrier aggregation (CA) scheme. This dynamic adjustment is utilized to avoid (or at least reduce) VCO, LO, and transmit signal coupling issues with multiple component carriers, with minimal (or at least reduced) current consumption by the VCO and the LO divider.

Abstract: Methods and apparatus including: setting up a plurality of configurations for a plurality of local oscillator (LO) paths of a carrier aggregation (CA) transceiver operating with a plurality of bands; calculating and comparing frequencies for each LO path of the plurality of LO paths and at least one divider ratio of LO dividers for each band of the plurality of bands to identify frequency conflicts; and reconfiguring the LO dividers for the plurality of LO paths and the plurality of bands when the frequency conflicts are identified.

Abstract: A CMOS amplifier including electrostatic discharge (ESD) protection circuits is disclosed. In one embodiment, the CMOS amplifier may include a PMOS transistor, a NMOS transistor, primary protection diodes, and one or more auxiliary protection diodes to limit a voltage difference between terminals of the CMOS amplifier. In some embodiments, the auxiliary protection diodes may limit the voltage difference between an input terminal of the CMOS amplifier and a supply voltage, the input terminal of the CMOS amplifier and ground, and the input terminal and the output terminal of the CMOS amplifier.

Abstract: An apparatus including: a plurality of amplifiers having a plurality of output ports, respectively, the plurality of amplifiers configured to amplify radio frequency (RF) signals received from at least one antenna; a plurality of demodulators configured to receive the amplified RF signals at a plurality of input ports, respectively, the plurality of demodulators configured to downconvert the received RF signals; and a plurality of switches configured to couple selected output ports of the plurality of amplifiers to selected input ports of the plurality of demodulators, wherein each switch of the plurality of switches is configured such that at least one of the plurality of output ports of the plurality of amplifiers is selectively coupled to any of multiple input ports of the plurality of input ports of the plurality of demodulators.

Abstract: Reconfiguring a transceiver design using a plurality of frequency synthesizers and a plurality of carrier aggregation (CA) receiver (Rx) and transmitter (Tx) chains, the method including: connecting a first frequency synthesizer to a first CA Tx chain; connecting the plurality of frequency synthesizers to the plurality of CA Rx chains, wherein a second frequency synthesizer of the plurality of frequency synthesizers is connected as a shared synthesizer to a first CA Rx chain and a second CA Tx chain.

Abstract: An amplifier module with an output coupler is disclosed. The amplifier module may include a plurality of input terminals and two or more output terminals. Each input terminal may be coupled to an input of an independent amplifier. Outputs from the independent amplifiers may be coupled to the two or more output terminals. The amplifier module may include an output coupler to couple the two or more output terminals together. A signal may be received by a first output terminal and be coupled by the output coupler to a second output terminal. In some embodiments, when the two or more output terminals are coupled together, the independent amplifiers may be made inactive or operated in a minimum gain configuration.

Abstract: An amplifier module with an output coupler is disclosed. The amplifier module may include a plurality of input terminals and two or more output terminals. Each input terminal may be coupled to an input of an independent amplifier. Outputs from the independent amplifiers may be coupled to the two or more output terminals. The amplifier module may include an output coupler to couple the two or more output terminals together. A signal may be received by a first output terminal and be coupled by the output coupler to a second output terminal. In some embodiments, when the two or more output terminals are coupled together, the independent amplifiers may be made inactive or operated in a minimum gain configuration.

Abstract: A radio frequency (RF) front end having multiple low noise amplifiers modules is disclosed. In an exemplary embodiment, an apparatus includes at least one first stage amplifier configured to amplify received carrier signals to generate at least one first stage carrier group. Each first stage carrier group includes a respective portion of the carrier signals. The apparatus also includes second stage amplifiers configured to amplify the first stage carrier groups. Each second stage amplifier configured to amplify a respective first stage carrier group to generate two second stage output signals that may be output to different demodulation stages where each demodulation stage demodulates a selected carrier signal.

Abstract: A CMOS amplifier including electrostatic discharge (ESD) protection circuits is disclosed. In one embodiment, the CMOS amplifier may include a PMOS transistor, a NMOS transistor, primary protection diodes, and one or more auxiliary protection diodes to limit a voltage difference between terminals of the CMOS amplifier. In some embodiments, the auxiliary protection diodes may limit the voltage difference between an input terminal of the CMOS amplifier and a supply voltage, the input terminal of the CMOS amplifier and ground, and the input terminal and the output terminal of the CMOS amplifier.