Method and apparatus for RC/CR phase error calibration of measurement receiver

An apparatus comprising:

• a resistor-capacitor/capacitor-resistor (RC-CR) circuit that includes an input node, a resistor capacitor (RC) path, and a capacitor resistor (CR) path and is configured to:
• output a first output signal and a second output signal having a non-zero phase differential with respect to one another;
• and
• output the first output signal and the second output signal having the non-zero phase differential with respect to one another by applying a phase-shift to an input signal received over the input node of the RC-CR circuit to obtain the first output signal and the second output signal, by outputting the first output signal over the RC path of the RC-CR circuit and by outputting the second output signal over the CR path of the RC-CR circuit,
• wherein the RC path of the RC-CR circuit includes an array of capacitors coupled in parallel and a plurality of switches, a first terminal of each capacitor in the array of capacitors being coupled to a common node and a second terminal of each capacitor in the array of capacitors being coupled to a ground of the RC-CR circuit through a corresponding switch in the plurality of switches,
• wherein the RC-CR circuit further comprises a first resistor, a first capacitor, and a second capacitor, a first terminal of the first resistor coupled to the ground of the RC-CR circuit through the first capacitor in series and a second terminal of the first resistor coupled to the input node of the RC-CR circuit, a common node of the first resistor and the first capacitor coupled to the RC path of the RC-CR circuit, the second capacitor having a first terminal coupled to the ground of the RC-CR circuit through a second resistor in series and a second terminal coupled to the input node of the RC-CR circuit, and
• wherein common node of the second resistor and the second capacitor is coupled to the CR path of the RC-CR circuit, each of the first resistor and the second resistor having a fixed resistance, and each of the first capacitor and the second capacitor having a fixed capacitance.