A radio frequency (RF) summer circuit having a characteristic impedance Zo comprises first and second ports coupled by first and second resistances, respectively, to a junction. The circuit further comprises a series combination of a third resistance and a switch movable between open and closed positions and an amplifier having input and output terminals and operable in an off state and an on state wherein the series combination is coupled across the input and output terminals of the amplifier between the junction and a third port. The first resistance, second resistance, and the third resistance are all substantially equal to Z.sub.0/3. Further, when the switch is moved to the closed position and the amplifier is switched to the off state a passive mode of operation is implemented and when the switch is moved to the open position and the amplifier is switched to the on state an active mode of operation is implemented. The RF summer circuit develops a summed signal at the third port equal to a sum of signals at the first and second ports modified by one of first and second gain values.

A radio frequency (RF) summer circuit having a characteristic impedance Zo comprises first and second ports coupled by first and second resistances, respectively, to a junction. The circuit further comprises a series combination of a third resistance and a switch movable between open and closed positions and an amplifier having input and output terminals and operable in an off state and an on state wherein the series combination is coupled across the input and output terminals of the amplifier between the junction and a third port. The first resistance, second resistance, and the third resistance are all substantially equal to Z.sub.0/3. Further, when the switch is moved to the closed position and the amplifier is switched to the off state a passive mode of operation is implemented and when the switch is moved to the open position and the amplifier is switched to the on state an active mode of operation is implemented. The RF summer circuit develops a summed signal at the third port equal to a sum of signals at the first and second ports modified by one of first and second gain values.

A method and system for digital feed-forward linearization. The system includes a main transmit path and an auxiliary transmit path. The main transmit path includes circuitries configured to process a transmit signal for transmission. The main transmit path includes a power amplifier (PA) for amplifying the transmit signal. The auxiliary transmit path includes circuitries configured to generate, in a digital domain, a distortion error signal corresponding to a distortion introduced to the transmit signal due to a non-linear characteristics of the PA in the main transmit path and convert the distortion error signal to an analog distortion error signal. The analog distortion error signal is combined with an output of the PA in the main transmit path. The auxiliary transmit path comprises a PA model circuit that mimics the behavior of the PA to generate a distorted transmit signal in a digital domain.

An amplifier circuit for a millimeter wave (mmW) communication system includes an amplifier coupled to a matching network, and a variable gain control circuit in the matching network, the variable gain control circuit having an adjustable gain control resistance, the adjustable gain control resistance having adjustable segments and a center node therebetween, the center node coupled to an alternating current (AC) ground.

An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

A second member is joined in surface contact with a first surface of a first member including a semiconductor region made from an elemental semiconductor. The second member includes a radio-frequency amplifier circuit made from a compound semiconductor. A conductive protrusion projects from the second member toward a side opposite to the first member. The first member includes a temperature measurement element that detects a temperature.

A second member is joined in surface contact with a first surface of a first member including a semiconductor region made from an elemental semiconductor. The second member includes a radio-frequency amplifier circuit made from a compound semiconductor. A conductive protrusion projects from the second member toward a side opposite to the first member. The first member includes a temperature measurement element that detects a temperature.

A power amplification device includes a first member in which a first circuit is formed, a second member in which a second circuit is formed, and a member-member connection conductor that electrically connects the first circuit and the second circuit to each other. The second member is mounted on the first member. The second circuit includes a first amplifier, which amplifies a radio frequency signal to output a first amplified signal. The first circuit includes a control circuit that controls an operation of the second circuit. At least part of a first termination circuit, which is connected to the first amplifier through the member-member connection conductor and which attenuates a harmonic wave component of the first amplified signal, is formed in the first member.

A power amplification device includes a first member in which a first circuit is formed, a second member in which a second circuit is formed, and a member-member connection conductor that electrically connects the first circuit and the second circuit to each other. The second member is mounted on the first member. The second circuit includes a first amplifier, which amplifies a radio frequency signal to output a first amplified signal. The first circuit includes a control circuit that controls an operation of the second circuit. At least part of a first termination circuit, which is connected to the first amplifier through the member-member connection conductor and which attenuates a harmonic wave component of the first amplified signal, is formed in the first member.