Broadcom Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Avago Technologies International Sales Pte. Limited

Takayuki Hayashi

Derek Tam

Ramon Alejandro Gomez

Jianhong Xiao

Jungwoo Song

Giuseppe Cusmai

Jasmine Cheng

Chun-Ying Chen

Loke Kun Tan

Lin He

Young J Shin

Danilo Manstretta

Flavio Avanzo

Systems and methods relate to providing a transmit signal. The transmit signal can be provided in a transmitter circuit including a main pre-equalizer, a main power amplifier in communication with the main pre-equalizer, a replica pre-equalizer, and a replica power amplifier in communication with the replica pre-equalizer. The replica preamplifier is in communication with the main pre-equalizer, and control signals are provided to the main pre-equalizer to reduce distortion. The control signals are provided in response to an output signal of the replica power amplifier.

System for and method of reducing transmit signal distortion

A method and apparatus is disclosed to couple a transmission amplifier and a reception amplifier to a shared medium. An output of the transmission amplifier is directly coupled to an input of the reception amplifier to form a common connection. The transmission amplifier and the reception amplifier may receive a first amplifier bias via the common connection. In response to the first amplifier bias, the transmission amplifier provides a first communication signal to the shared medium and the reception amplifier does not provide a second communication signal from the shared medium. Alternatively, the transmission amplifier and the reception may receive a second amplifier bias via the common connection. In response to the second amplifier bias, the reception amplifier provides the second communication signal from the shared medium and the transmission amplifier does not provide the first communication signal to the shared medium.

Direct coupled radio frequency (RF) transceiver front end

Embodiments of the present invention provide systems and methods for automatic amplifier gain profile control, including a method for automatically configuring a variable gain profile amplifier according to received input and a variable gain profile amplification system. Further, embodiments of the present invention provide systems and methods for increased gain profile accuracy, including methods and systems to reduce the effects of temperature and/or process variations on the gain profile of an amplifier.

Amplifier with automatic gain profile control and calibration

A circuit with dielectric thicknesses is presented that includes a low-pass filter including one or more semiconductor devices having a thick gate oxide layer, while further semiconductor devices of the circuit have thin gate oxide layers. The low-pass filter semiconductor device includes an N-type substrate, a P-type region formed on the N-type substrate, a thick gate oxide layer formed over the P-type region, a Pgate electrode formed over the thick gate oxide layer and coupled to a first voltage supply line, and Ppick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line. The low-pass filter semiconductor device acts as a capacitor, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the circuit.

Thick oxide P-gate NMOS capacitor for use in a low-pass filter of a circuit and method of making same

A system and method for over-voltage protection of a power amplifier is provided. A power amplifier is typically employed in a transmitter to amplify signals prior to transmission via a load; the load may include an antenna or a cable. As a result of an impedance mismatch between the power amplifier and its load, excess power from the power amplifier output fails to reach the load and must be dissipated by one or more transistors in the power amplifier. In severe impedance mismatch conditions, this dissipated power may damage or destroy the transistor(s). An automatic gain control (AGC) is provided for detecting a gain difference between the power amplifier and a replica power amplifier. A gain difference may signal an over-voltage situation. The AGC may be configured to adjust the gain of the power amplifier if a gain difference exists to prevent device damage.

System and method for over-voltage protection of a power amplifier

A mixer produces an improved output signal during frequency translation of an input signal using a local oscillator (LO) signal. The mixer includes five component mixers connected in parallel. Each component mixer uses a phase-shifted version of the LO signal for frequency translation to produce a component output signal from the input signal. The component output signals are scaled according to corresponding gain factors and combined to form the output signal. When the mixer is used in a receiver, the phases of the component LO signals and the gain factors are configured to substantially cancel overlapping baseband versions of component input signals located at the third, fifth, seventh and ninth harmonics of the LO frequency. When used in a transmitter, the same phase and gain factor configurations substantially cancel third, fifth, seventh and ninth harmonics within the output signal.

High-order harmonic rejection mixer using multiple LO phases

An RF mixer includes a plurality of submixers coupled to a single input transistor pair and a single tail current source. An input LO signal is divided into multiple individual waveforms, each having a different phase. The phase differences are even in that the phase difference between any two time-adjacent individual waveforms is approximately equal to the phase difference between any other two time-adjacent individual waveforms. The submixers are appropriately scaled so that the individual waveforms, when summed, create a piecewise linear LO signal. The submixers also combine the individual waveforms with an input baseband signal to produce an output signal or to produce a baseband signal from an input mixed signal. In order to reduce noise in the system, only one submixer is active at any time. Further, polarities of some individual waveforms are reversed so that to avoid signal cancellation when by combining waveforms of opposite polarities.

RF mixer with high local oscillator linearity using multiple local oscillator phases

A programmable divider includes a synchronous counter configured to process an input clock signal and produce first output signals in response the input clock signal. A number of logic devices are coupled to the synchronous counter and configurable to receive the first output signals and correspondingly produce second output signals. Also included is a multiplexer that is configured to receive the second output signals and has an output coupled to an input of the synchronous counter. In the programmable divider, characteristics of the synchronous counter are selectable based upon a particular number of the logic devices configured.

Programmable divider with built-in programmable delay chain for high-speed/low power application

In a low-pass filter for a phase locked loop (PLL) circuit, a capacitor formed by an N-type substrate, a P-type region formed on the N-type substrate, a thick oxide formed over the P-type region, a P gate electrode formed over the thick oxide and coupled to a first voltage supply line, and P pick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the PLL.

Growing community of inventors

Lake Forest, CA, United States of America

Takayuki Hayashi