Analog Devices,inc.

Christoph M Steinbrecher

Ekrem Oran

Christopher Mayer

Alexandru Aurelian Ciubotaru

Reza Alavi

Saeed Aghtar

Santosh Anil Kudtarkar

John Poelker

Christopher O'Neill

Xizhen Xu

Fatih Kocer

Faith Kocer

Omar A S Abdel Fattah

Arathi Sundaresan

Po-Hao Yeh

Quadrature error correction (QEC) for radio transceivers are provided herein. In certain embodiments, a transceiver includes an in-phase (I) signal path including a first controllable amplifier coupled to a first data converter, and a quadrature-phase (Q) signal path including a second controllable amplifier coupled to a second data converter. The transceiver further includes a QEC circuit operable to correct for a quadrature error between the I signal path and the Q signal path by adjusting a gain of the first controllable amplifier and/or a gain of the second controllable amplifier.

Quadrature error correction for radio transceivers

Apparatus and methods for control and calibration of tunable filters are provided. In certain embodiments, a tunable filter includes at least one controllable component (for instance, a controllable inductor or a controllable capacitor) having a value that changes or adjusts a center frequency of the tunable filter. For example, the controllable component can correspond to a controllable inductor or a controllable capacitor of an inductor-capacitor (LC) resonator of the tunable filter. The tunable filter further includes a control circuit implemented with an approximation function for estimating a value of the controllable component for achieving a desired center frequency indicated by a frequency control signal.

Apparatus and methods for control and calibration of tunable filters

Apparatus and methods for tunable filtering are provided. In certain embodiments, a tunable filter is implemented using one or more controllable capacitors formed on a semiconductor die and using one or more shielded integrated inductors formed on a secondary circuit board that attaches to a carrier circuit board. Additionally, the shielded integrated inductors are formed from patterned metallization layers of the secondary circuit board, and shielding is provided on the secondary circuit board and/or the carrier circuit board to shield the inductors from the semiconductor die and/or other components.

Apparatus and methods for tunable filtering

A two-input amplifier is disclosed. The amplifier can include an amplification path for a first input signal that can have adjustable flatness or high-frequency peaking, and an amplification path for a second input that can be substantially independent of the frequency-shaping aspect of the first-input path. The first-input amplification path can include an operational amplifier as an active device and a plurality of passive elements for frequency shaping. The second-input amplification path can include a device that injects its output current into a node of the first path. The signals of the two paths can be combined and appear substantially independently of each other at the output of the amplifier.

Two-input amplifier

Embodiments of the present invention may provide a signal processor with a wide gain range. The signal processor may comprise at least a discrete step gain stage and a continuous variable gain amplifier (VGA) stage. The discrete step gain stage may comprise a programmable gain amplifier (PGA) (e.g., low noise amplifiersand(LNAand LNA)). The VGA stage may provide a continuous range to compensate the LNAs gain steps. In one embodiment, the AGC controller enables an inherent hysteresis with the AGC step change if required.

RF AGC control

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Pennington, NJ, United States of America

Christoph M Steinbrecher