Abstract: A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

Abstract: A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

Abstract: Methods and apparatus are provided for detection of voltage levels of RF signals. A first voltage correction is provided based on a thermal voltage and a second voltage correction is provided based on a voltage difference between a detection transistor, used for the rectification of the RF signal, and a reference transistor, to which the RF signal is not supplied. Based on the first and second voltage corrections, a more accurate detector with greater linearity may be obtained. In an embodiment, the second voltage correction may be generated proportional to a hyperbolic tangent of the voltage difference between two transistors, obtained using an additional pair of transistors configured as a differential pair. Applications include the control of a power amplifier output in a wireless device.

Abstract: Apparatus and methods for power amplifiers that can operate under a wide range of supply voltages are disclosed herein. In certain implementations, a method of adjusting a parameter of a power amplifier is provided. The method includes detecting a value of a supply voltage provided to the power amplifier. The method further includes selecting a first value from a plurality of values for a first parameter of the power amplifier based on the detected value of the supply voltage. The method further includes adjusting the first parameter of the power amplifier to the first value.

Abstract: Aspects of this disclosure relate to compensating for dynamic error vector magnitude. A compensation circuit can generate a compensation signal based at least partly on an amount of time that an amplifier, such as a power amplifier, is turned off between successive transmission bursts of the amplifier. For example, the compensation circuit can charge a capacitor based at least partly on an amount of time that the amplifier is turned off between successive transmission bursts and generate the compensation signal based at least partly on an amount of charge stored on the capacitor. A bias circuit can receive the compensation signal, generate a bias signal based at least partly on the compensation signal, and provide the bias signal to the amplifier to bias the amplifier.

Abstract: A bias circuit provides additional bias current for power amplifiers during data bursts to compensate for the gain droop caused by a rise in the power amplifier temperature during the data burst. A bias circuit includes a difference amplifier and switches coupled to the difference amplifier. The switches operate the bias circuit in a first mode when a transmit data burst is detected and operate the bias circuit in a second mode after the bias circuit has operated in the first mode for a predetermined period of time. In the first mode, the bias circuit charges a storage capacitor and sets an output current to zero. In the second mode, the bias circuit outputs the output current that increases above the initial value of zero as the PA warms up, where the excursion of this increase of current is determined by a register. The switches disable the bias circuit when the transmit data burst ends.

Abstract: 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.

Abstract: Aspects of this disclosure relate to compensating for dynamic error vector magnitude. A compensation circuit can generate a compensation signal based at least partly on an amount of time that an amplifier, such as a power amplifier, is turned off between successive transmission bursts of the amplifier. For example, the compensation circuit can charge a capacitor based at least partly on an amount of time that the amplifier is turned off between successive transmission bursts and generate the compensation signal based at least partly on an amount of charge stored on the capacitor. A bias circuit can receive the compensation signal, generate a bias signal based at least partly on the compensation signal, and provide the bias signal to the amplifier to bias the amplifier.

Abstract: A bias circuit provides additional bias current for power amplifiers during data bursts to compensate for the gain droop caused by a rise in the power amplifier temperature during the data burst. A bias circuit includes a difference amplifier and switches coupled to the difference amplifier. The switches operate the bias circuit in a first mode when a transmit data burst is detected and operate the bias circuit in a second mode after the bias circuit has operated in the first mode for a predetermined period of time. In the first mode, the bias circuit charges a storage capacitor and sets an output current to zero. In the second mode, the bias circuit outputs the output current that increases above the initial value of zero as the PA warms up, where the excursion of this increase of current is determined by a register. The switches disable the bias circuit when the transmit data burst ends.

Abstract: 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.

Abstract: A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

Abstract: 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.

Abstract: Methods and apparatus are provided for detection of voltage levels of RF signals. A first voltage correction is provided based on a thermal voltage and a second voltage correction is provided based on a voltage difference between a detection transistor, used for the rectification of the RF signal, and a reference transistor, to which the RF signal is not supplied. Based on the first and second voltage corrections, a more accurate detector with greater linearity may be obtained. In an embodiment, the second voltage correction may be generated proportional to a hyperbolic tangent of the voltage difference between two transistors, obtained using an additional pair of transistors configured as a differential pair. Applications include the control of a power amplifier output in a wireless device.

Abstract: A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

Abstract: Apparatus and methods for power amplifiers that can operate under a wide range of supply voltages are disclosed herein. In certain implementations, a method of adjusting a parameter of a power amplifier is provided. The method includes detecting a value of a supply voltage provided to the power amplifier. The method further includes selecting a first value from a plurality of values for a first parameter of the power amplifier based on the detected value of the supply voltage. The method further includes adjusting the first parameter of the power amplifier to the first value.

Abstract: A bias circuit provides additional bias current for power amplifiers during data bursts to compensate for the gain droop caused by a rise in the power amplifier temperature during the data burst. A bias circuit includes a difference amplifier and switches coupled to the difference amplifier. The switches operate the bias circuit in a first mode when a transmit data burst is detected and operate the bias circuit in a second mode after the bias circuit has operated in the first mode for a predetermined period of time. In the first mode, the bias circuit charges a storage capacitor and sets an output current to zero. In the second mode, the bias circuit outputs the output current that increases above the initial value of zero as the PA warms up, where the excursion of this increase of current is determined by a register. The switches disable the bias circuit when the transmit data burst ends.

Abstract: Apparatus and methods for power amplifiers that can operate under a wide range of supply voltages are disclosed herein. In certain implementations, a method of adjusting a parameter of a power amplifier is provided. The method includes detecting a value of a supply voltage provided to the power amplifier. The method further includes selecting a first value from a plurality of values for a first parameter of the power amplifier based on the detected value of the supply voltage. The method further includes adjusting the first parameter of the power amplifier to the first value.

Abstract: A bias circuit provides additional bias current for power amplifiers during data bursts to compensate for the gain droop caused by a rise in the power amplifier temperature during the data burst. A bias circuit includes a difference amplifier and switches coupled to the difference amplifier. The switches operate the bias circuit in a first mode when a transmit data burst is detected and operate the bias circuit in a second mode after the bias circuit has operated in the first mode for a predetermined period of time. In the first mode, the bias circuit charges a storage capacitor and sets an output current to zero. In the second mode, the bias circuit outputs the output current that increases above the initial value of zero as the PA warms up, where the excursion of this increase of current is determined by a register. The switches disable the bias circuit when the transmit data burst ends.

Abstract: Power detectors for radio-frequency applications. In some embodiments, an amplifier can include an amplification stage having an input and an output, and a detector coupled to the output of the amplification stage and configured to generate an input signal representative of power associated with an amplified signal provided by the amplification stage. The detector can be further configured to generate an output signal based at least in part on a compensation signal resulting from a combination of a first current representative of the input signal and a second current representative of an operating condition associated with the amplifier.

Abstract: A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.