Passive radar experiences a significant problem called multipath clutter. The Batch version of the Extensive Cancellation Algorithm (ECA-B) is an efficient method for clutter mitigation. With the increase in signal bandwidth, a greater number of segments is required to cancel the clutter across the entire frequency range. This affects the processing rate, detrimentally weakening and modulating the signal from low-speed targets. Thus, this paper proposes a method that uses ECA-B to process both reference and echo signals in the frequency domain. This method not only reduces the amount of calculation required but also avoids weakening and modulating the target signal, which is spread across many segments. The simulated and experimental data results confirm the correctness and validity of the proposed method.