What is the total bandwidth of an FM phone transmission having a 5 kHz deviation and a 3 kHz modulating frequency?

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Multiple Choice

What is the total bandwidth of an FM phone transmission having a 5 kHz deviation and a 3 kHz modulating frequency?

For FM signals, the total bandwidth is described by Carson's rule: B ≈ 2(Δf + f_m), where Δf is the peak frequency deviation and f_m is the highest modulating frequency. Here Δf = 5 kHz and f_m = 3 kHz, so B ≈ 2(5 + 3) = 16 kHz. This reflects the carrier plus the significant sidebands generated by the modulating signal up to 3 kHz. Thus the transmission uses about 16 kHz of RF bandwidth. The other numbers would omit part of the modulation sidebands or the deviation, so they don’t represent the full bandwidth.

For FM signals, the total bandwidth is described by Carson's rule: B ≈ 2(Δf + f_m), where Δf is the peak frequency deviation and f_m is the highest modulating frequency. Here Δf = 5 kHz and f_m = 3 kHz, so B ≈ 2(5 + 3) = 16 kHz. This reflects the carrier plus the significant sidebands generated by the modulating signal up to 3 kHz. Thus the transmission uses about 16 kHz of RF bandwidth. The other numbers would omit part of the modulation sidebands or the deviation, so they don’t represent the full bandwidth.

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