Apparatus and method for calibrating image rejection in radio frequency circuitry

In a radio frequency (RF) receiver for receiving an RF input signal and converting the RF input signal to an input signal at another frequency, a method for image rejection correction comprising:

• generating a tone signal at an image frequency;
• mixing said tone signal with an RF tuning signal to provide an image signal;
• correcting said image signal using an image correction network having first and second coefficients to provide a corrected signal;
• determining a wanted energy level of said corrected signal;
• determining best values of said first and second coefficients in response to said wanted energy level of said corrected signal;
• and
• correcting the input signal at the other frequency using said best values in said image correction network.

In a radio frequency (RF) receiver for receiving an RF input signal and converting the RF input signal to an intermediate frequency (IF) input signal before converting the IF input signal to a baseband signal, a method for image rejection correction comprising:

• correcting the IF input signal using an image correction network having current values of first and second coefficients to provide a corrected IF input signal;
• generating a tone signal at the image frequency;
• mixing said tone signal with an RF tuning signal to provide an IF image signal;
• changing at least one of said current values to at least one other value;
• correcting said IF image signal using said image correction network having said at least one other value to provide a corrected image signal;
• determining a wanted energy level of said filtered signal;
• comparing said wanted energy level with a prior wanted energy level calculated using said current values;
• forming next values as either said current values or said at least one other value based on said comparing;
• and
• correcting the IF input signal using said next values using said filter.