Beceem Communications Inc.

Aspendos Communications

Beecem Communications Inc.

Korhan Titizer

Derek Keith Shaeffer

Peter Capofreddi

Sriraman Dakshinamurthy

Tushar Ramanlal Shah

Gerald K Wong

Joel L Dawson

Arvin Ramesh Shahani

Apparatus, systems, and methods are described that implement techniques for estimating a relative rotation between a first complex signal and a second complex signal. In apparatus form, a rotation-estimation circuit includes a first quadrant detector and receives the first and second complex signals and produces an estimate of the relative rotation between the complex signals. A variable rotator receives the estimate of the relative rotation and rotates at least one of the first and second complex signals using the estimate of the relative rotation. In method form, a first quadrant estimate is calculated that corresponds to the relative rotation between the first and second complex signals, and at least one of the first and second complex signals is rotated using the quadrant estimate of the relative rotation.

Phase rotation estimation

A Doherty power amplifier is provided that includes a main amplifier device and an auxiliary amplifier device. The Doherty power amplifier further includes a phase compensation network. The phase compensation network is configured to maintain a substantially constant phase of one of an output signal from the main amplifier device or an output signal from the auxiliary amplifier device across a range of input powers. The Doherty power amplifier further includes an impedance inverter for power combining an output signal of the main amplifier device with an output signal of the auxiliary amplifier device.

Doherty power amplifier with phase compensation

A Doherty amplifier that includes a main amplifier device and an auxiliary amplifier device. The main amplifier device includes a plurality of independently controllable amplifier segments. The system further includes a coupler for coupling an input signal to each of the main amplifier device and the auxiliary amplifier device. The system further includes an impedance inverter for power combining an output signal of the main amplifier device with an output signal of the auxiliary amplifier device.

High efficiency doherty amplifier with a segmented main amplifier

A transconductance cell is disclosed that includes a first transistor and a second transistor. A regulator regulates an average voltage in response to a reference voltage, where the average voltage corresponds to the average of a voltage at a bias terminal of the first transistor and a voltage at a bias terminal of the second transistor. A mixer including the transconductance cell is also disclosed. In the mixer, the transconductance cell receives a differential input voltage and produces a differential output current. The mixer also includes one or more switches that multiply the differential output current with an oscillator signal. A method is disclosed that includes measuring an average voltage of a voltage at a bias terminal of a first transistor and a voltage at a bias terminal of a second transistor and regulating the average voltage responsive to the measured average voltage and a reference voltage.

Increasing the linearity of a transconductance cell

Circuits, methods, and systems are provided for opening a primary feedback loop in a transmitter. An auxiliary feedback loop can be closed when the primary feedback loop is opened, and a controller can match a gain of the primary feedback loop to another gain in the transmitter.

Method and apparatus for opening a feedback loop

A circuit is provided that includes a Cartesian feedback loop. The Cartesian feedback loop includes one or more operational amplifiers. At least one of the operational amplifiers includes two or more cascaded amplifier stages and one or more bypass amplifier stages. The bypass amplifier stages are connected in parallel with the cascaded amplifier stages.

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Saratoga, CA, United States of America

Korhan Titizer