The present application provides a window function processing module including an integrating circuit, configured to receive an integrating input signal, the integrating circuit comprising an operational amplifier; an integrating capacitor, coupled to an output terminal and a first input terminal of the operational amplifier; and an adjustable impedance module, coupled between the first input terminal of the operational amplifier and an integrating input terminal of the integrating circuit, wherein the adjustable impedance module is controlled by at least one control signal to adjust an impedance value of the adjustable impedance module; and a control unit, coupled to the integrating circuit, configured to generate the at least one control signal according to a window function, to adjust the integration gain of the integrating circuit, such that the integrating output signal is related to an operation result of the integrating input signal and the window function.