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: A filter circuit may include a first path having a first complex baseband filter. The circuit may further include a second path having a second complex baseband filter. The circuit may further include a combiner coupled to an output of the first complex baseband filter and an output of the second complex baseband filter.

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: A circuit includes an active balun having an RF signal input and having differential signal outputs, the active balun including a first pair of transistors coupled to the RF signal input, the first pair of transistors including a first transistor of a first type and a second transistor of a second type, wherein the first type and second type are complementary; and an intermodulation distortion (IMD) sink circuit having an operational amplifier (op amp) coupled between a first node and a second node, wherein the first transistor and second transistor are coupled in series between the first node and the second node.

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: A reconfigurable filter circuit has a first path including a transimpedance amplifier (TIA). The transimpedance amplifier has an input that receives an input current and an output that outputs a voltage. The reconfigurable filter circuit also includes a switchable feedback path. The switchable feedback path includes a first low-pass filter coupled to an output of the TIA. The switchable feedback path also includes a first switch to couple the feedback path to provide a feedback current to the first path resulting in a bandpass response in the output voltage when the switch is closed and a low-pass response in the output voltage when the switch is open.

Abstract: A method and apparatus are disclosed for a configurable mixer capable of operating in a linear, a legacy, and a low-power mode. In the linear mode, the configurable mixer is configured to operate as a double-balanced mixer to multiply a first differential signal by a second differential signal. In the legacy mode, the configurable mixer is configured to as a double-balanced mixer to multiply a differential signal by a single-ended signal. In the low-power mode, the configurable mixer is configured to operate as a single-balanced mixer to multiply a differential signal by a single-ended signal. The operating mode of the configurable mixer may be based, at least in part, on a mode control signal. In some embodiments, the configurable mixer may be included in an analog front end of a wireless communication device.

Abstract: A method and apparatus are disclosed for a configurable mixer capable of operating in a linear, a legacy, and a low-power mode. In the linear mode, the configurable mixer is configured to operate as a double-balanced mixer to multiply a first differential signal by a second differential signal. In the legacy mode, the configurable mixer is configured to as a double-balanced mixer to multiply a differential signal by a single-ended signal. In the low-power mode, the configurable mixer is configured to operate as a single-balanced mixer to multiply a differential signal by a single-ended signal. The operating mode of the configurable mixer may be based, at least in part, on a mode control signal. In some embodiments, the configurable mixer may be included in an analog front end of a wireless communication device.

Abstract: A circuit includes an active balun having an RF signal input and having differential signal outputs, the active balun including a first pair of transistors coupled to the RF signal input, the first pair of transistors including a first transistor of a first type and a second transistor of a second type, wherein the first type and second type are complementary; and an intermodulation distortion (IMD) sink circuit having an operational amplifier (op amp) coupled between a first node and a second node, wherein the first transistor and second transistor are coupled in series between the first node and the second node.

Abstract: A reconfigurable filter circuit has a first path including a transimpedance amplifier (TIA). The transimpedance amplifier has an input that receives an input current and an output that outputs a voltage. The reconfigurable filter circuit also includes a switchable feedback path. The switchable feedback path includes a first low-pass filter coupled to an output of the TIA. The switchable feedback path also includes a first switch to couple the feedback path to provide a feedback current to the first path resulting in a bandpass response in the output voltage when the switch is closed and a low-pass response in the output voltage when the switch is open.

Abstract: A device includes a first stacked capacitor comprising a first MOS capacitance and a first MOM capacitance, the first MOS capacitance coupled to a first node, the first node configured to receive a first bias voltage, and a second stacked capacitor comprising a second MOS capacitance and a second MOM capacitance, the second MOS capacitance coupled to the first node.

Abstract: Techniques for designing baseband processing circuitry for radio IC's. In an aspect, techniques for differential-to-single-ended conversion in a baseband portion of the IC are disclosed to reduce the pin count and package size for RF IC's. In another aspect, the converter includes selectable narrowband and wideband amplifiers, wherein the wideband amplifiers may be implemented using transistor devices having smaller area than corresponding transistor devices of narrowband amplifiers. Further techniques for bypassing one or more elements, and for implementing a low-pass filter of the converter using an R-C filter network, are described.

Abstract: A device includes a first stacked capacitor comprising a first MOS capacitance and a first MOM capacitance, the first MOS capacitance coupled to a first node, the first node configured to receive a first bias voltage, and a second stacked capacitor comprising a second MOS capacitance and a second MOM capacitance, the second MOS capacitance coupled to the first node.

Abstract: Techniques for designing baseband processing circuitry for radio IC's. In an aspect, techniques for differential-to-single-ended conversion in a baseband portion of the IC are disclosed to reduce the pin count and package size for RF IC's. In another aspect, the converter includes selectable narrowband and wideband amplifiers, wherein the wideband amplifiers may be implemented using transistor devices having smaller area than corresponding transistor devices of narrowband amplifiers. Further techniques for bypassing one or more elements, and for implementing a low-pass filter of the converter using an R-C filter network, are described.