US 9,002,310 B2 · IP2 calibration methods and techniques

Abstract

Some embodiments of the present disclosure relate to improved techniques for performing IP2 calibration in receivers having two complementary data paths (e.g., i-data path and q-data path). In these techniques, one of the two data paths (e.g., the i-data path) is used to generate a reference signal for the other data path (e.g., the q-data path), and/or vice versa. The other data path then performs calibration using the reference signal. Compared to previous techniques (which required separate, dedicated circuitry for generating a reference signal), the inventive techniques reduce the amount of circuitry and correspondingly reduce the manufacturing costs and power consumption. This is because the inventive techniques use the existing circuitry in complementary fashion during calibration (e.g., during calibration an i-data path generates a reference signal for a q-data path, and vice versa).

Claims21

Dependent claims

A calibration circuit, comprising:

an in-phase receive data path;
a quadrature receive data path;
a correlation element to correlate received in-phase data from the in-phase receive data path with received quadrature data from the quadrature receive data path to obtain a correlation result;
a first tuning circuit coupled between the correlation element and the in-phase receive data path and configured to receive the correlation result from the correlation element, wherein the first tuning circuit provides an in-phase receive data tuning signal that is based on the correlation result to compensate for distortion on the in-phase receive data path;
and
a second tuning circuit coupled between the correlation element and the quadrature receive data path, wherein the second tuning circuit provides a quadrature receive data tuning signal based on the correlation result to compensate for distortion on the quadrature receive data path.

3 more elements

A receiver, comprising:

a radio-frequency (RF) antenna to receive an RF signal over a frequency channel;
an in-phase receive data path and a quadrature receive data path coupled to the RF antenna, wherein the in-phase receive data path provides an in-phase received data signal by mixing the RF signal with an LO signal, and wherein the quadrature receive data path provides a quadrature received data signal by mixing the RF signal with a phase-shifted LO signal;
a first tuning circuit to selectively introduce distortion on the in-phase receive data path, wherein the distortion distorts the received in-phase data signal during a first time period to provide a first reference signal;
a correlation element to correlate the first reference signal with the quadrature received data signal during the first time period to generate a first correlation result;
and
a second tuning circuit configured to receive the first correlation result from the correlation element and to selectively introduce distortion on the quadrature receive data path during the first time period according to a quadrature received data calibration value, wherein the quadrature received data calibration value is based on the first correlation result.

3 more elements

A calibration method, comprising:

receiving an RF signal over a frequency channel;
mixing the RF signal with an LO signal to provide an in-phase received data signal;
mixing the RF signal with a phase-shifted LO signal to provide a quadrature received data signal;
using a first amplitude modulated interference signal during a first time interval to distort the in-phase received data signal to provide a first reference signal, and to distort the quadrature received data signal to provide a first error signal;
correlating the first reference signal with the first error signal to generate a first correlation result;
and
altering the quadrature receive data signal during the first time period according to a first calibration tuning value, wherein the first calibration tuning value is based on the first correlation result.

4 more elements

Dependencies are inferred from the claim text.

IP2 calibration methods and techniques

Life of this patent

IP2 calibration methods and techniques

Life of this patent

Abstract

Claims21