Passband bandwidth for FM

[sajib333]

For Amplitude Modulation, it is understood that the bandwidth of a passband signal is always twice as much as that of a baseband signal, for example
if the bandwidth/max frequency of a message/baseband signal is 1 kHz and a carrier of 1 MHz is modulated with this baseband, then a "sum" frequency is produced at 1 MHz + 1 kHz, and a difference frequency is produced at 1 MHz - 1 kHz. Hence, the passband bandwidth is 2 KHz.
Now, My question is what would have been the bandwidth of the baseband signal, if it were a Frequency Modulation (FM)? Consider the frequency remains same, i.e. Baseband signal is 1 KHz and Carrier signal is 1 MHz.

Thanks in Advance.

 

[naturemalett]

Therically the bandwidth of FM signal is infinite according to the bessel function. From the engineering viewpoint,we take the bandwidth which consisit of 90% energy as the bandwidth of the signal.

 

[goal]

we have a equation for FM bandwidth in basic books like electronic communications by george kennedy.
FM BW = 2(max frequency deviation from carrier+highest modulating frequency)