US 2015/0030102 A1Published application

Wideband quadrature error correction

AssigneeAnalog Devices, Inc.

InventorsRaju Hormis, Steven R. Bal, Kevin Glenn Gard, Jianxun Fan, David J. McLaurin, Antonio Montalvo

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Abstract

A transmission module is provided that includes a transmitter, a loopback receiver, and a QEC controller. In a first state, the QEC controller calibrates the loopback receiver to remove quadrature imbalance in the loopback receiver. In a second state, a communication pathway is provided between the transmitter and the loopback receiver, and the QEC controller identifies quadrature imbalance in the transmitter based at least one a comparison of the data signals at the output of the loopback receiver with data signals at the input of the transmitter. Based on the comparison, the QEC controller can adjust one or more characteristics of the transmitter to correct quadrature errors in the transmitter.

Claims21

Dependent claims

A transmission module comprising:

a switching module;
a transmitter communicatively coupled to the switching module;
a loopback receiver communicatively coupled to the switching module;
a calibration module communicatively coupled to the switching module;
and
a controller communicatively coupled to the loopback receiver and the transmitter;
wherein in a first state, the switching module is configured to provide a communication pathway between an output of the calibration module and an input of the loopback receiver, and the controller is configured to identify and correct quadrature imbalance in the loopback receiver based at least on a comparison of the output of the loopback receiver with an expected output;
wherein in a second state, the switching module is configured to provide a communication pathway between an output of the transmitter and an input of the loopback receiver, and the controller is configured to:
identify quadrature imbalance in the transmitter based at least partly on a comparison of a data signal received from the loopback receiver with a buffered data signal that corresponds to a data signal received by the transmitter, and
adjust one or more characteristics of the transmitter to correct the identified quadrature imbalance present in the transmitter based at least partly on the comparison.

7 more elements

A transmission module comprising:

a transmitter;
a loopback receiver;
and
a controller configured to:
calibrate the loopback receiver to account for quadrature imbalance in the loopback receiver,
receive a data signal from the calibrated loopback receiver that corresponds to a data signal received by the transmitter,
identify quadrature imbalance in the transmitter based at least partly on a comparison of the data signal received from the calibrated loopback receiver with a buffered data signal that corresponds to the data signal received by the transmitter, and
adjust one or more characteristics of the transmitter to correct the identified quadrature imbalance based at least partly on the comparison.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/951,341Filed 25 Jul 2013
Published: 29 Jan 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

H04L 1/243
By comparing a transmitted test signal with a locally generated replica: at the transmitter, using a loop-back
H03F 3/245
Of transmitter output stages: with semiconductor devices only
H03F 3/45475
Characterised by the way of implementation of the active amplifying circuit in the differential amplifier: using IC blocks as the active…
H04B 17/14
For calibration: of the whole transmission and reception path, e.g. self-test loop-back