719results about "Push-pull amplifiers" patented technology

A balanced high-frequency device is constituted by a balanced device and a phase circuit. The input side of the balanced device is connected to an input terminal IN serving as an unbalanced input / output terminal and the output side of it is connected to output terminals OUT1 and OUT2 serving as balanced input / output terminals. Moreover, the phase circuit is connected between the output terminals.

A radio frequency integrated circuit includes a power amplifier, a low noise amplifier, a first transformer balun, and a second transformer balun. The power amplifier includes a first power amplifier section and a second power amplifier section. When enabled, the first and second power amplifier sections amplify an outbound radio frequency (RF) signal to produce a first amplified outbound RF signal and a second amplified outbound RF signal, respectively. The power amplifier provides the first amplified outbound RF signal to the first transformer balun and the second outbound RF signal to the second transformer balun, where the first transformer balun is coupled to a first antenna and the second transformer balun is coupled to a second antenna. The low noise amplifier includes a first low noise amplifier section and a second low noise amplifier section. When enabled, the first low noise amplifier section amplifies a first inbound RF signal to produce a first amplified inbound RF signal, and, when enabled, the second low noise amplifier section amplifies a second inbound RF signal to produce a second amplified inbound RF signal. The low noise amplifier receives the first inbound RF signal from the first transformer balun and receives the second inbound RF signal from the second transformer balun.

Embodiments of RF power amplifiers are disclosed that include switched-mode power amplifiers supplied by synchronous buck DC-DC converters. The switched-mode power amplifiers can be used to amplify a limited form of an RF input signal and the supply to the switched-mode power amplifier is varied in response to the envelope of the RF input signal. One embodiment includes a switched-mode power amplifier connected to a synchronous buck DC-DC converter.

In one embodiment, the present invention includes multiple gain stages to receive and amplify a differential input signal at different common mode voltages. The stages each may include a pair of linear NMOS gain transistors coupled to a primary coil of a given output transformer. One of the stages may include commonly coupled terminals coupled to a center tap of the primary coil of an output transformer of another stage, and a supply current provided to one of the stages is re-used for the other stage(s).

A differential amplifier includes a differential amplifying stage and an output amplifying stage. The output amplifying stage includes a first transistor for pull-up, a second transistor for pull-down, a capacitor element, and switches. The first transistor for pull-up is connected across an output terminal and a high potential side power supply VDD and has a control terminal to which is connected a first differential output. The second transistor for pull-down is connected across the output terminal and a low potential side power supply VSS and has a control terminal to which is connected a second differential output. The switches interchangeably connect the capacitor element across the output terminal and the control terminal of the first transistor for pull-up or across the output terminal and the control terminal of the second transistor for pull-down.