Broadcom Corporation

Marvell International Limited

Danilo Manstretta

Rinaldo Castello

Fernando De Bernardinis

Takayuki Hayashi

Marco Garampazzi

Nicola Codega

Fernando DeBernardinis

Stefano Dal Toso

Paulo Mateus Mendes

A voltage-controlled oscillator comprises a tank circuit and first and second pairs of transistors. Each transistor comprises a gate, a drain, and a source. The drains of the first pair are coupled to the tank circuit and the gates of the first pair are cross-coupled with the drains of the first pair. The drains of the second pair are coupled to the tank circuit and the gates of the second pair are cross-coupled with the drains of the second pair. The oscillator includes a first resonant filter comprising a first terminal coupled to the sources of the first pair and a second resonant filter comprising a first terminal coupled to the sources of the second pair. A method includes adjusting capacitance in a resonant filter to cause the resonant filter to resonate based on a selected frequency.

Voltage-controlled oscillator

An amplifier and a method are provided for converting a single ended signal to an amplified differential signal. The amplifier comprises an input configured to receive a single ended signal, a differential amplifier that outputs an amplified differential signal based on the single ended signal, and a compensator coupled to the differential amplifier and configured to inject an adjusted distortion compensating signal based on the even order distortion signal to compensate for a distortion in the amplified differential signal. The method comprises receiving a single ended signal, converting the single ended signal to an amplified differential signal, and generating a distortion compensating signal to substantially cancel an even order distortion signal injected to the differential signal by the converting.

Even order distortion cancellation in single-ended input, differential output amplifiers using feed-back

An amplifier and a method for converting a single ended signal to an amplified differential signal. The amplifier comprises an input configured to receive a single ended signal, a differential amplifier that outputs an amplified differential signal based on the single ended signal, and a compensator coupled to the differential amplifier and configured to inject an adjusted distortion compensating signal based on the even order distortion signal to compensate for a distortion in the amplified differential signal. The method comprises receiving a single ended signal, converting the single ended signal to an amplified differential signal, and generating a distortion compensating signal to substantially cancel an even order distortion signal injected to the differential signal by the converting.

Even order distortion cancellation in single-ended input, differential output amplifiers using feedback

The variable gain amplifier includes a forward path that provides the amplifier variable gain, and a feedback path. The feedback path uses a switch that is turned on at low gain levels. The switch taps into the feedback resistor, shunting it to signal-ground and eliminating the feedback mechanism. This ensures that the input impedance seen at the input port does not grow excessively, using part of the feedback resistor as a passive termination at low gain levels. In this way variable gain ranges in excess of 30 dB can be achieved.

Impedance matched variable gain low noise amplifier using shunt feed-back

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

A power detector having temperature compensation for improved measurement performance includes a pair of rectifier transistors coupled to a differential input signal biased by a first temperature dependent current. An output of the pair of rectifier transistors provides a first component of a differential DC output signal. The first component of the differential DC output signal includes a DC voltage proportional to an amplitude of the differential input signal plus an offset voltage. The power detector further includes a reference transistor biased by a reference current. The reference current includes a second temperature dependent current and a temperature independent offset current for temperature compensation. An output of the reference transistor provides a second component of the differential DC output signal that includes a reference voltage. The temperature independent offset current is adjusted such that the reference voltage substantially equals the offset voltage, thereby improving the precision of the power detector.

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Stradella, Italy

Danilo Manstretta