Plot multiple s1p plots on one graph

s1p_plot.py

import matplotlib.pyplot as plt
import matplotlib.patches as patches
import skrf as rf

def plot_s1p(title, path, files):
    fig, (ax) = plt.subplots(1,1, figsize=(20,10))
    out = ""
    for f in files:
        net = rf.Network(path+f)
        net.frequency.unit = "mhz"
        net.plot_s_db(0, 0, label = f)
        out += "File: {} S11@868MHz: {:.03f}\r\n".format(f, net['868MHz'].s_db[0,0,0])
    
    ax.add_patch(patches.Rectangle([867e6, -50], 2e6, 50, facecolor='red', alpha=0.5))
    ax.grid(b=True, which='both', axis='both')
    ax.set_title(title)
    plt.legend()
    fig.canvas.draw()
    fig.tight_layout()
    fig.show()
    
    print(out)
    
plot_s1p("device1", "C:\\pathy\\path\\", ["file1.s1p", "file2.s1p", "file3.s1p"])