A calibration apparatus is used for calibrating characteristics of a power amplifier (PA) in a transmitter. The calibration apparatus includes an adaptive bias generator circuit that is used to track an envelope of an input signal received by control terminals of transistors of the PA and generate an adaptive bias voltage to the control terminals of the input transistors in response to the envelope of the input signal.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

Amplification with post-distortion compensation is disclosed. In an example aspect, an apparatus includes a voltage rail and a cascode amplifier. The cascode amplifier includes an amplification node, a cascode node, and a common-source node. The cascode amplifier also includes at least one cascode transistor, an input transistor, and a compensation transistor. The cascode transistor is coupled between the amplification node and the cascode node. The input transistor is coupled between the cascode node and the common-source node. The compensation transistor is coupled between the voltage rail and the cascode node.

Amplification with post-distortion compensation is disclosed. In an example aspect, an apparatus includes a voltage rail and a cascode amplifier. The cascode amplifier includes an amplification node, a cascode node, and a common-source node. The cascode amplifier also includes at least one cascode transistor, an input transistor, and a compensation transistor. The cascode transistor is coupled between the amplification node and the cascode node. The input transistor is coupled between the cascode node and the common-source node. The compensation transistor is coupled between the voltage rail and the cascode node.

Disclosed are systems and methods related to reducing intermodulation products in an RF output signal by matching an impedance of the power amplifier to an impedance of the antenna and concurrently blocking signals having a second fundamental frequency received by the antenna when the antenna is transmitting to inhibit intermodulation products of the first and second fundamental frequencies from re-radiating from the antenna. The matching and blocking are performed concurrently by a single circuit with combined matching and blocking functionality.

Disclosed are systems and methods related to reducing intermodulation products in an RF output signal by matching an impedance of the power amplifier to an impedance of the antenna and concurrently blocking signals having a second fundamental frequency received by the antenna when the antenna is transmitting to inhibit intermodulation products of the first and second fundamental frequencies from re-radiating from the antenna. The matching and blocking are performed concurrently by a single circuit with combined matching and blocking functionality.

A communication device includes a power amplifier that generates power signals according to one or more operating bands of communication data, with the amplitude being driven and generated in output stages of the power amplifier. The final stage can include an output passive network that suppresses suppress an amplitude modulation-to-phase modulation (AM-PM) distortion. During a back-off power mode a bias of a capacitive unit of the output power network component can be adjusted to minimize an overall capacitance variation. A output passive network can further generate a flat-phase response between dual resonances of operation.

A communication device includes a power amplifier that generates power signals according to one or more operating bands of communication data, with the amplitude being driven and generated in output stages of the power amplifier. The final stage can include an output passive network that suppresses suppress an amplitude modulation-to-phase modulation (AM-PM) distortion. During a back-off power mode a bias of a capacitive unit of the output power network component can be adjusted to minimize an overall capacitance variation. A output passive network can further generate a flat-phase response between dual resonances of operation.

An amplification circuit configured to generate an output signal by differentially amplifying first and second input signals. The first and second input signals are a differential signal pair. Alternatively, the first input signal is a single-ended signal, and the second input signal is a reference signal. The amplification circuit is configured to perform a differential amplification operation by increasing a gain for generating an output signal based on the first input signal.