A modulating signal $2\sin \left(6.28\times {10}^6\right)$ t is added to the carrier signal 4sin$\left(12.56\times {10}^9\right)\mathrm{t}$ for amplitude modulation. The combined signal is passed through a non-linear square law device. The output is then passed through a band pass filter. The bandwidth of the output signal of band pass filter will be___MHz.