An apparatus is disclosed, comprising means for storing reference data indicative of characteristics for each of two or more amplifiers for amplifying signals in two or more respective bands, the reference data including voltage characteristics required by the particular amplifier to achieve a particular output power for a range of output power values for its respective frequency band. The apparatus may comprise means for receiving at least a first required output power for a first amplifier and a second required output power for a second amplifier, and determining, based on the reference data, the voltage characteristics required for the first amplifier to achieve the first required output power and the voltage characteristics required for the second amplifier to achieve the second required output power.

Disclosed in the present invention are a radio frequency power amplifier based on power detection feedback, a chip, and a communication terminal. The radio frequency power amplifier comprises multiple stages of amplifier circuits and at least one power detection feedback circuit; the input end of the power detection feedback circuit is connected to the output end of a current stage of amplifier circuit, and the output end of the power detection feedback circuit is connected to the input ends of the current stage of amplifier circuit and at least one stage of amplifier circuit located prior to the current stage of amplifier circuit. The power detection feedback circuit generates, according to the detected output power of the current stage of amplifier circuit, a control voltage varying inversely with the output power, so that the power detection feedback circuit outputs current varying positively with the control voltage.

An integrated circuit architecture and circuitry is defined by a die structure with a plurality of exposed conductive pads arranged in a grid of rows and columns. The die structure has a first operating frequency region with a first transmit and receive chain, and a second operating frequency region with a second transmit chain and a second receive chain. There is a shared region of the die structure defined by an overlapping segment of the first operating frequency region and the second operating frequency region with a shared power supply input conductive pad connected to the first transmit chain, the second transmit chain, the first receive chain, and the second receive chain, and a shared power detection output conductive pad connected to the first transmit chain and the second transmit chain.

In certain aspects, a method is provided for measuring power using a resistive element coupled between a power amplifier and an antenna. The method includes squaring a voltage from a first terminal of the resistive element to obtain a first signal, squaring a voltage from a second terminal of the resistive element to obtain a second signal, and generating a measurement signal based on a difference between the first signal and the second signal. In some implementations, the resistive element is implemented with a power switch.

Disclosed in the present invention are a radio frequency power amplifier based on current detection feedback and a chip. The radio frequency power amplifier comprises multiple stages of amplifier circuits and at least one current detection feedback circuit; the input end of the current detection feedback circuit is connected to the input end of a current stage of amplifier circuit among the multiple stages of amplifier circuits by means of a corresponding resistor, and the output end of the current detection feedback circuit is connected to the input end of at least one stage of amplifier circuit prior to the current stage of amplifier circuit. The current detection feedback circuit generates, according to the detected quiescent operating current of the current stage of amplifier circuit, a control voltage varying inversely with the quiescent operating current, so that the current detection feedback circuit outputs current varying positively with the control voltage.

A power amplifier circuitry (100) comprises: a transistor stack (110) comprising at least two stacked transistor units (112A, 112B, 112C) for amplifying input signals; wherein each stacked transistor unit (112A, 112B, 112C) comprises a plurality of controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N), each comprising a segment transistor (122, 132, 142), wherein source terminals (123, 133, 143) within each transistor unit are connected, drain terminals (125, 135, 145) within each transistor unit are connected and gate terminals (124, 134, 144) within each transistor unit are connected, wherein each segment transistor (122, 132, 142) further comprises a back gate terminal (126, 136, 146) for setting a body bias, wherein at least two of the segment transistors (122, 132, 142) within each transistor unit have independently connected back gate terminals (126, 136, 146); and a control unit (190) configured to control the body bias for selecting an amplifier class of each of the controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N) of each of the stacked transistor units (112A, 112B, 112C).

An amplifier circuit includes an input terminal to which a radio frequency signal is input, an amplifier transistor that has a control terminal and amplifies the radio frequency signal, a bias circuit that includes an emitter-follower circuit or a source-follower circuit and supplies a bias current to the control terminal of the amplifier transistor, an inductor arranged in series between an emitter of the emitter-follower circuit and the control terminal of the amplifier transistor or between a source of the source-follower circuit and the control terminal of the amplifier transistor, and a variable resistance circuit connected to the inductor.

An amplification circuit includes a switch circuit, an amplifier, and a control circuit. The switch circuit has a first terminal coupled to a radio frequency signal input terminal or a system voltage terminal, a second terminal coupled to an input terminal of the amplifier, and a control terminal configured to receive a control signal. The amplifier amplifies a radio frequency signal. The control circuit generates the control signal according to a driving current generated by the amplifier. When the control circuit determines that the amplifier operates in a high power mode, the control circuit controls the control signal to adjust a conducting level between the first terminal and the second terminal of the switch circuit according to the intensity of the driving current.

In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

Device and method are disclosed for downlink gain compensation at a radio unit. According to an embodiment, the device comprises a pre-distortion circuit, a digital gain adjuster, a gain determiner and a first gain controller. The pre-distortion circuit is configured to generate and apply a pre-distortion to an input signal. The digital gain adjuster is configured to apply an adjustable gain to an output signal from the pre-distortion circuit. The gain determiner is configured to determine a gain difference between a target downlink gain and current downlink gain. The first gain controller is configured to control the digital gain adjuster based on the gain difference. A radio unit comprising the device is also disclosed.