plt.figure(dpi=300)
ax = plt.axes()
plt.rcParams['figure.facecolor'] = 'white'
plt.tight_layout(pad=3, w_pad=4.8, h_pad=3.6)
plt.tick_params(direction = "in")
plt.xticks(fontsize = 18,fontweight='bold')
plt.yticks(fontsize = 18,fontweight='bold')
plt.setp(ax.spines.values(), linewidth =2)
ax.xaxis.set_tick_params(width=2)
ax.yaxis.set_tick_params(width=2)
plt.xlabel("Freq. (GHz)",fontweight = "bold", fontsize="18")
plt.ylabel(r"Linewidth $\Delta$H (Oe)", fontweight = "bold", fontsize="18")
plt.legend(prop=dict(weight='bold'), loc='upper left', bbox_to_anchor=(1, 0.5))
ratio = 1.1
xleft, xright = ax.get_xlim()
ybottom, ytop = ax.get_ylim()
ax.set_aspect(abs((xright-xleft)/(ybottom-ytop))*ratio)