Abstract: An apparatus is disclosed for current-mode filtering using current steering. In an example aspect, the apparatus includes a filter. The filter includes a current-steering node, a first output node, a second output node, a wideband path, and a narrowband path. The wideband path is coupled between the current-steering node and the first output node. The wideband path includes a wideband low-pass filter configured to pass frequencies within a wide passband. The narrowband path is coupled between the current-steering node and the second output node. The narrowband path includes a narrowband low-pass filter configured to pass a portion of the frequencies that are within a narrow passband.

Abstract: Various aspects described herein relate to low-loss multi-band multiplexing schemes for a wireless communications system, for example, a 5th Generation (5G) New Radio (NR) system. In an aspect, a multiplexer for multi-band wireless communications comprises at least one tuning component configured to transmit or receive at least one signal within a frequency band that is selected from a plurality of frequency bands. The multiplexer further comprises at least one combining component, communicatively coupled with the at least one tuning component, configured to transmit or receive the at least one signal within the selected frequency band. In an aspect, the at least one tuning component is integrated on a chip and the at least one combining component is not integrated on the chip.

Abstract: A receiver may include a time-interleaved charge sampler comprising a charge sampler switch in series with a charge sampler capacitor. The receiver may also include a current buffer configured to drive the time-interleaved charge sampler.

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 relate to multi-band filter architectures and methods for filtering signals using the multi-band filter architectures. One example multi-band filter generally includes a transconductance-capacitance (gm-C) filter and a reconfigurable load impedance coupled to an output of the gm-C filter, the reconfigurable load impedance comprising a first gyrator circuit coupled to a second gyrator circuit.

Abstract: A switchable amplifier exhibits multiple modes of operation including a current mode and a voltage mode. The switchable amplifier includes a first transistor having a gate terminal coupled to a drain terminal, one or more second transistors having a gate terminal coupled to the gate terminal of the first transistor, a third transistor and a bias resistor across the third transistor. The third transistor is coupled between the gate terminal of the first transistor and the gate terminal of the one or more second transistors.

Abstract: The present disclosure provides an apparatus that includes a first mixer circuit configured to convert between an RF signal and an IF signal based at least in part on an local oscillator (LO) signal. The first mixer circuit is electrically coupled to a first node that is configured to receive the LO signal and a first bias voltage, a second node that is configured to receive the RF signal or the IF signal, and a third node that is configured to provide the IF signal or the RF signal. The apparatus further includes a second mixer circuit electrically coupled to a fourth node configured to receive the LO signal and a second bias voltage, the second node, and the third node. The second bias voltage has a voltage level that is offset from the first bias voltage.

Abstract: An apparatus is disclosed for current-mode filtering with switching. In an example aspect, the apparatus includes a filter including two input nodes, two output nodes, two differential paths, two bypass nodes respectively coupled between the two input nodes and the two output nodes along the two differential paths, a high-pass filter coupled between the two bypass nodes and the two output nodes, two low-pass switches, a band-pass switch, and a low-pass filter coupled in series with the high-pass filter along the two differential paths. The high-pass filter includes two series capacitors, which are respectively coupled between the two bypass nodes and the two output nodes, and two shunt inductors, which are respectively coupled to the two bypass nodes. The two low-pass switches are respectively coupled in parallel with the two series capacitors. The band-pass switch is coupled in series between the two shunt inductors.

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: Certain aspects of the present disclosure relate to multi-band filter architectures and methods for filtering signals using the multi-band filter architectures. One example multi-band filter generally includes a transconductance-capacitance (gm-C) filter and a reconfigurable load impedance coupled to an output of the gm-C filter, the reconfigurable load impedance comprising a first gyrator circuit coupled to a second gyrator circuit.

Abstract: Methods, systems, and devices for wireless communication are described for enhanced broadband operation of an active mixer. In an example, an apparatus may include an active mixer that converts between radio frequency (RF) signals and intermediate frequency (IF) signals based at least in part on an alternating current (AC) local oscillator (LO) signal, wherein a direct current (DC) current generated within the active mixer is dependent in part on a bias voltage and the AC LO signal. The apparatus may include a mixer biasing circuit that generates the bias voltage for the active mixer, a magnitude of the bias voltage having an inverse relationship to an amplitude of the AC LO signal.

Abstract: Devices and techniques are described to extract specific frequency band signals from a wide-band radio-frequency signal. A network entity may include an antenna for receiving the wide-band radio-frequency signal and may include a receiver circuit for processing the wide-band radio-frequency signal. The receiver circuit may include a transconductance amplifier and a plurality of single-band circuits. The transconductance amplifier may be configured to generate an amplified wide-band radio-frequency signal and send it to one or more of the single-band circuits. Each single-band circuit may be configured to extract a different frequency band signal from the amplified wide-band radio-frequency signal.

Abstract: In certain aspects, a circuit comprises a low noise amplifier (LNA) configured to receive a radio frequency (RF) signal, a first mixer coupled to the low noise amplifier (LNA), and a first trans-impedance filter coupled to the first mixer. The first trans-impedance filter comprises a tunable inductor and capacitor (LC) network configured to be a portion of a doubly terminated LC ladder filter and a trans-impedance amplifier (TIA) coupled to the tunable inductor and capacitor (LC) network. The circuit further comprises a second mixer coupled to the low noise amplifier (LNA) and a second trans-impedance filter coupled to the second mixer.

Abstract: Devices and techniques are described to extract specific frequency band signals from a wide-band radio-frequency signal. A network entity may include an antenna for receiving the wide-band radio-frequency signal and may include a receiver circuit for processing the wide-band radio-frequency signal. The receiver circuit may include a transconductance amplifier and a plurality of single-band circuits. The transconductance amplifier may be configured to generate an amplified wide-band radio-frequency signal and send it to one or more of the single-band circuits. Each single-band circuit may be configured to extract a different frequency band signal from the amplified wide-band radio-frequency signal.

Abstract: Various aspects described herein relate to low-loss multi-band multiplexing schemes for a wireless communications system, for example, a 5th Generation (5G) New Radio (NR) system. In an aspect, a multiplexer for multi-band wireless communications comprises at least one tuning component configured to transmit or receive at least one signal within a frequency band that is selected from a plurality of frequency bands. The multiplexer further comprises at least one combining component, communicatively coupled with the at least one tuning component, configured to transmit or receive the at least one signal within the selected frequency band. In an aspect, the at least one tuning component is integrated on a chip and the at least one combining component is not integrated on the chip.

Abstract: Methods, systems, and devices for wireless communication are described for enhanced broadband operation of an active mixer. In an example, an apparatus may include an active mixer that converts between radio frequency (RF) signals and intermediate frequency (IF) signals based at least in part on an alternating current (AC) local oscillator (LO) signal, wherein a direct current (DC) current generated within the active mixer is dependent in part on a bias voltage and the AC LO signal. The apparatus may include a mixer biasing circuit that generates the bias voltage for the active mixer, a magnitude of the bias voltage having an inverse relationship to an amplitude of the AC LO signal.

Abstract: An apparatus includes a phase detector coupled to an output of a frequency multiplier. A digital loop filter is coupled to the phase detector, and a duty cycle correction circuit is coupled to the digital loop filter.

Abstract: A method and system for self-powering a clock input buffer is disclosed. The system includes an input node adapted to receive an alternating current (AC) signal having an instantaneous voltage oscillating between a minimum voltage and a maximum voltage. The system includes a pass transistor having a voltage controlled terminal, a first transfer terminal, and a second transfer terminal. The first transfer terminal connects to the input node and the second transfer terminal connects to a power node. The circuit also includes a plurality of transistors adapted to form a logic gate connected to the power node, and having a sensing terminal connected to the input node and an output terminal connected to the voltage controlled terminal. The logic gate produces a control voltage on the output terminal in response to an input voltage on the sensing terminal. The circuit also includes an energy-storage element having a first terminal connected to the power node.

Abstract: A level-shifter is provided in which the devices may all be sized approximately the same yet a known startup state is provided at power-up by forming the level-shifter using a one-sided NMOS latch. The one-sided NMOS latch is powered through a pair of head-switch transistors. A pair of pull-down transistors function to flip a binary state for the one-sided NMOS latch.

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.