import numpy as np
from scipy.fft import rfft, rfftfreq


sample_rate = 200.0
duration = 1.0
sample_count = int(sample_rate * duration)
time = np.arange(sample_count) / sample_rate

signal = (
    1.2 * np.sin(2.0 * np.pi * 30.0 * time)
    + 0.4 * np.sin(2.0 * np.pi * 75.0 * time)
)