Abstract: A method for calibrating a radio transceiver begins by injecting a low-frequency tone at a transmit power amplifier input of the radio transceiver, where the low frequency tone is at least an order of magnitude lower than the operating frequency of a local oscillator coupled to the transmitter input. The method continues by upconverting the low-frequency tone to produce a plurality of tones at a transmit power amplifier output and then determining which tone of the plurality of tones is a local oscillator feedthrough tone associated with a transmit power amplifier output and which tone of the plurality of tones is representative of an in-phase and quadrature (I/Q) imbalance associated with the transmit power amplifier output.

Abstract: A method for calibrating a radio transceiver begins by injecting a low-frequency tone at a transmit power amplifier input of the radio transceiver, where the low frequency tone is at least an order of magnitude lower than the operating frequency of a local oscillator coupled to the transmitter input. The method continues by upconverting the low-frequency tone to produce a plurality of tones at a transmit power amplifier output and then determining which tone of the plurality of tones is a local oscillator feedthrough tone associated with a transmit power amplifier output and which tone of the plurality of tones is representative of an in-phase and quadrature (I/Q) imbalance associated with the transmit power amplifier output.

Abstract: A sign switching circuitry is disclosed. In one aspect, the sign switching circuitry includes a first and second differential common-source amplifier having common differential input nodes and common differential output nodes configured such that a differential input signal applied at the common differential input nodes is amplified to a differential output signal at the common differential output nodes with a fixed gain by the first amplifier and by the fixed gain with opposite sign by the second amplifier. The sign switching circuitry also includes a switching circuitry configured to activate the first common-source amplifier and deactivate the second common-source amplifier to amplify the differential input signal by the fixed gain, and to activate the second common-source amplifier and deactivate the first common-source amplifier to amplify the differential input signal by the fixed gain with opposite sign.

Abstract: A digitally controlled variable gain amplifier (VGA) for generating amplification output levels is disclosed. In one aspect, the digitally controlled VGA includes a positive amplification stage including at least two positive amplifiers, and a corresponding negative amplification stage coupled to the positive amplification stage. The negative amplification stage includes at least two negative amplifiers. The positive amplification stage and the corresponding negative amplification stage are digitally controlled by one or more digital codes. The corresponding negative amplification stage is coupled in parallel with the positive amplification stage and is equally weighted as the positive amplification stage, and both the positive amplification stage and the corresponding negative amplification stage selectively contribute to the generation of the amplification output levels for the digitally controlled VGA.

Abstract: A digital radio-frequency (RF) circuitry is disclosed. In one aspect, the circuitry includes a digitally controlled amplifier configured to receive an RF input signal and a digital control signal, and to output an amplitude controlled output signal. The digitally controlled amplifier includes one or more common-source amplifying unit cells. A respective common-source amplifying unit cell includes a sources node connected to a switching circuitry controllable by the digital control signal so as to activate or deactivate the common-source amplifying unit cell. The switching circuitry comprises a first switch configured to connect the source node with a first power supply node and a second switch configured to connect the source node with a second power supply node when activating and deactivating, respectively, the common-source amplifying unit cell.

Abstract: A sign switching circuitry is disclosed. In one aspect, the sign switching circuitry includes a first and second differential common-source amplifier having common differential input nodes and common differential output nodes configured such that a differential input signal applied at the common differential input nodes is amplified to a differential output signal at the common differential output nodes with a fixed gain by the first amplifier and by the fixed gain with opposite sign by the second amplifier. The sign switching circuitry also includes a switching circuitry configured to activate the first common-source amplifier and deactivate the second common-source amplifier to amplify the differential input signal by the fixed gain, and to activate the second common-source amplifier and deactivate the first common-source amplifier to amplify the differential input signal by the fixed gain with opposite sign.

Abstract: A digital radio-frequency (RF) circuitry is disclosed. In one aspect, the circuitry includes a digitally controlled amplifier configured to receive an RF input signal and a digital control signal, and to output an amplitude controlled output signal. The digitally controlled amplifier includes one or more common-source amplifying unit cells. A respective common-source amplifying unit cell includes a sources node connected to a switching circuitry controllable by the digital control signal so as to activate or deactivate the common-source amplifying unit cell. The switching circuitry comprises a first switch configured to connect the source node with a first power supply node and a second switch configured to connect the source node with a second power supply node when activating and deactivating, respectively, the common-source amplifying unit cell.

Abstract: A digitally controlled variable gain amplifier (VGA) for generating amplification output levels is disclosed. In one aspect, the digitally controlled VGA includes a positive amplification stage including at least two positive amplifiers, and a corresponding negative amplification stage coupled to the positive amplification stage. The negative amplification stage includes at least two negative amplifiers. The positive amplification stage and the corresponding negative amplification stage are digitally controlled by one or more digital codes. The corresponding negative amplification stage is coupled in parallel with the positive amplification stage and is equally weighted as the positive amplification stage, and both the positive amplification stage and the corresponding negative amplification stage selectively contribute to the generation of the amplification output levels for the digitally controlled VGA.

Abstract: Front-end systems for a transmitter included in a radio device are disclosed. An example front-end system may comprise a voltage-to-power mixer. The voltage-to-power mixer may be configured to up-convert a baseband signal to a high-frequency signal by multiplying the baseband signal with a local oscillator signal. Additionally, the voltage-to-power mixer may include a voltage feedback circuit. The example front-end system may further comprise a two-stage power amplifier. The two-stage power amplifier may be configured to amplify the high-frequency signal.