1. waveform shaping: In-phase integration circuit can convert aperiodic or non-sinusoidal signals into smoother waveforms. Through integration, the rapidly changing part of the signal will gradually smooth to the slowly changing part, thus making the waveform of the signal more stable and continuous. This helps to reduce the noise and interference in the signal, thus improving the quality and clarity of the signal.

2. Frequency analysis: The co-directional integration circuit can also analyze the frequency component of the signal. By integrating the input signal, the amplitude of the output result is related to the frequency component of the input signal. This enables the in-phase integration circuit to be used to detect components with different frequencies in the signal and select the frequency range of interest by adjusting the parameters of the integration circuit.