Built-in tuning of RFIC Passive Polyphase Filter by process and thermal monitoring

A built-in tuning circuit of RadioFrequency (RF) Passive Polyphase Filter (PPF) for image rejection in low Intermediate Frequency (IF) receiver is presented. The resistance values of the filter are process dependent and can severely impact the circuit performances if not controlled. In order to overcome this limitation, an in-line auto-calibration of the PPF resistance values, based on Design Of Experiment (DOE) methodology, is presented. Using DOE, a model is derived from thermal and process deviations of the chip responses. This approach results in a robust and low cost solution.