Second order intercept point (IP2) calibration for wireless receivers

摘要

IP2 calibration efficiency can be improved by passing the calibration signal through the transceiver's duplexer instead of inserting the calibration signal directly onto transceivers receive circuit. Passing the calibration signal through the duplexer may reduce IP2 calibration periods for transceivers having less-permeable duplexers, or duplexers that provide better than average separation between the RX and TX circuits. IP2 calibration inefficiencies can also be reduced by using a binary-like search when computing the in-phase and quadrature-phase path correction coefficients of the IP2 correction code.

主权项

1. A method for second order intercept point (IP2) calibration of a wireless transceiver, the method comprising:
transmitting, by an independent IP2 signal generator coupled between a transmit port of a duplexer and a power amplifier in a transmit circuit of the wireless transceiver, a calibration signal directly into and over the transmit port of the duplexer, wherein the duplexer comprises a receive port coupled to a receive circuit of the wireless transceiver and the transmit port coupled to the transmit circuit of the wireless transceiver, the calibration signal being a known signal specifically configured to obtain IP2 calibration parameters for the receive circuit of the wireless transceiver, and the independent IP2 signal generator being separate and distinct from the wireless transceiver, and wherein a portion of the calibration signal leaks from the transmit port to the receive port of the duplexer and propagates over the receive circuit; and analyzing the portion of the calibration signal that leaks from the transmit port to the receive port of the duplexer to determine the IP2 calibration parameters for the receive circuit of the wireless transceiver.