The formula that calculates this bandwidth is called CARSON’S RULE. CARSON’S RULE requires knowing the modulating frequency and the maximum frequency deviation of the transmitted carrier. … Since there are many Bessel Function sidebands beyond 180KHz, FM channels must be spaced considerably farther apart than 180KHz.

## What is Carson’s rule for FM bandwidth?

In telecommunication, Carson’s bandwidth rule defines **the approximate bandwidth requirements of communications system components for a carrier signal that is frequency modulated by a continuous or broad spectrum of frequencies** rather than a single frequency.

## What determines the bandwidth used by any given FM communications system?

The Bandwidth of Frequency Modulation Signal

Recall, the bandwidth of a complex signal like FM is the difference between its highest and lowest frequency components, and is expressed in **Hertz (Hz)**. Bandwidth deals with only frequencies.

## What determines the bandwidth used by any given FM Communications System Why are two different types of bandwidth used in frequency modulated transmissions?

The bandwidth of a frequency modulated signal varies with **both deviation and modulating frequency**. Increasing modulating frequency increases the frequency separation between sidebands. Increasing modulating frequency for a given level of deviation reduces modulation index.

## Why bandwidth of FM is infinite?

FM generates upper and lower sidebands, each of which contain an infinite number of side frequencies. However, the **FM bandwidth is not infinite because the amplitude of the higher order side frequencies decreases rapidly**.

## How do I check my FM bandwidth?

Carson’s rule estimates the FM signal bandwidth as **BT = 2(75 + 15) = 180 kHz** which is six times the 30 kHz bandwidth that would be required for AM modulation.

## What is Carson’s rule formula?

Note 1: The Carson bandwidth rule is expressed by the relation **CBR = 2( f + f _{m})** where CBR is the bandwidth requirement, f is the carrier peak deviation frequency, and f

_{m}is the highest modulating frequency.

## What are the advantages of frequency modulation?

**The main advantages of FM over AM are:**

- Improved signal to noise ratio (about 25dB) w.r.t. to man made interference.
- Smaller geographical interference between neighboring stations.
- Less radiated power.
- Well defined service areas for given transmitter power.