Abstract: Apparatuses and methods are disclosed regarding a multiband transmitter. In an example aspect, an apparatus for processing signals for wireless transmission includes a wireless interface device. The wireless interface device includes an upconverter, a tunable filter, and a driver amplifier. The upconverter has an output and is configured to upconvert a baseband frequency to a radio frequency based on a local oscillator signal. The tunable filter has an input and an output; the input of the tunable filter is coupled to the output of the upconverter. The driver amplifier has an input; the input of the driver amplifier is coupled to the output of the tunable filter.

Abstract: An area-efficient balun and a method for signal processing using such a balun. One example balun generally includes a winding and a clamping circuit. The winding is formed by a coiled trace including a first portion having a first trace width and a second portion having a second trace width, the second trace width being narrower than the first trace width. The clamping circuit has a first terminal and a second terminal, the first terminal of the clamping circuit being coupled to the first portion of the coiled trace.

Abstract: A transceiver circuit includes transmit circuitry comprising a transmit baseband filter and a driver amplifier having an output coupled to a power amplifier, receive circuitry comprising a low noise amplifier and a receive baseband filter, mixer circuitry and a magnetic circuit, wherein the mixer circuitry and the magnetic circuit are coupled between the transmit baseband filter and the driver amplifier, and are further coupled between the low noise amplifier and the receive baseband filter, wherein the mixer circuitry and the magnetic circuit are shared between the transmit circuitry and the receive circuitry in a time division duplexing (TDD) communication system.

Abstract: An area-efficient balun and a method for signal processing using such a balun. One example balun generally includes a winding and a clamping circuit. The winding is formed by a coiled trace including a first portion having a first trace width and a second portion having a second trace width, the second trace width being narrower than the first trace width. The clamping circuit has a first terminal and a second terminal, the first terminal of the clamping circuit being coupled to the first portion of the coiled trace.

Abstract: Apparatuses and methods are disclosed regarding a multiband transmitter. In an example aspect, an apparatus for processing signals for wireless transmission includes a wireless interface device. The wireless interface device includes an upconverter, a tunable filter, and a driver amplifier. The upconverter has an output and is configured to upconvert a baseband frequency to a radio frequency based on a local oscillator signal. The tunable filter has an input and an output; the input of the tunable filter is coupled to the output of the upconverter. The driver amplifier has an input; the input of the driver amplifier is coupled to the output of the tunable filter.

Abstract: A modulator may include a controller configured to receive in-phase (I) baseband signals and quadrature-phase (Q) baseband signals. The controller may be configured to select a section of a region defined by a number of local oscillator (LO) phases. The controller may be configured to output multiple control signals and a pair of phase selection signals. The modulator may further include multiple output stages. Each output stage may be coupled to the controller to receive a pair of the control signals, the pair of phase selection signals, and multiple offset LO signals. Each of the output stages may include a unit element.

Abstract: A modulator may include a controller configured to receive in-phase (I) baseband signals and quadrature-phase (Q) baseband signals. The controller may be configured to select a section of a region defined by a number of local oscillator (LO) phases. The controller may be configured to output multiple control signals and a pair of phase selection signals. The modulator may further include multiple output stages. Each output stage may be coupled to the controller to receive a pair of the control signals, the pair of phase selection signals, and multiple offset LO signals. Each of the output stages may include a unit element.

Abstract: An amplifier may include a first transistor. The amplifier may also include a second transistor coupled to the first transistor in an output stage of the amplifier. The amplifier may also include a level shift resistor coupled between a gate of the first transistor and a gate of the second transistor. The amplifier may further include a feedback bias circuit coupled to the gate of the first transistor and the gate of the second transistor through the level shift resistor. The feedback bias circuit may be configured to sense a common mode voltage of the output stage of the amplifier, and to compare the common mode voltage with a reference voltage to control a resistor bias current conducted by the level shift resistor.

Abstract: An amplifier may include a first transistor. The amplifier may also include a second transistor coupled to the first transistor in an output stage of the amplifier. The amplifier may also include a level shift resistor coupled between a gate of the first transistor and a gate of the second transistor. The amplifier may further include a feedback bias circuit coupled to the gate of the first transistor and the gate of the second transistor through the level shift resistor. The feedback bias circuit may be configured to sense a common mode voltage of the output stage of the amplifier, and to compare the common mode voltage with a reference voltage to control a resistor bias current conducted by the level shift resistor.