Frequency response calibration for radio frequency integrated circuit with multiple receiving channels

A method of characterizing a radio frequency integrated circuit (RFIC) having multiple receiving channels, wherein each of the receiving channels has a mixer, an analog front end (AFE) filter coupled to the mixer, and an analog-to-digital converter (ADC) coupled to the AFE filter, wherein the method comprises:

• bypassing a first AFE filter in a first receiving channel of the RFIC and bypassing a second AFE filter in a second receiving channel of the RFIC;
• calculating a first frequency estimate of the RFIC at a first measuring frequency using first data captured by the ADCs of the RFIC while the first AFE filter and the second AFE filter are bypassed, wherein the first frequency estimate comprises a first amplitude estimate and a first phase estimate for the first receiving channel, and comprises a second phase estimate for the second receiving channel;
• enabling the first AFE filter in the first receiving channel and bypassing the second AFE filter in the second receiving channel;
• calculating a second frequency estimate of the RFIC at the first measuring frequency using second data captured by the ADCs while the first AFE filter is enabled and the second AFE filter is bypassed, wherein the second frequency estimate comprises a third amplitude estimate and a third phase estimate for the first receiving channel, and comprises a fourth phase estimate for the second receiving channel;
• and
• calculating a frequency response of the first AFE filter at the first measuring frequency, comprising:
• calculating an amplitude response of the first AFE filter based on the first amplitude estimate and the third amplitude estimate;
• and
• calculating a phase response of the first AFE filter based on the first phase estimate and the third phase estimate.