Frequency Modulation - Summary
In the **Frequency Modulation PDF**, the frequency of the carrier is adjusted according to the instantaneous value of the modulating signal. While the amplitude and phase remain constant, the frequency modulation index is typically greater than 1. This technique usually requires a high bandwidth, around 200 kHz. FM operates within a very high-frequency range, generally between 88 to 108 Megahertz.
To create a frequency-modulated (FM) signal, the frequency of the radio carrier changes according to the amplitude of the incoming audio signal. When the voltage in the information signal increases, the frequency of the carrier rises, and when it decreases, the frequency of the carrier also drops.
Understanding Frequency Modulation
Frequency Modulation Formula
The FM modulated signal can be expressed as:
y(t) = A cos(2 π fc t + kf ∫t x(α) dα + φ0)
where A is the carrier amplitude, kf is the frequency deviation constant, and φ0 is the initial phase offset.
Frequency Modulation Equations
Mathematically, it can be represented as:
m(t) = Am cos(ωm t + Ɵ) ……………… 1
Here, m(t) represents the modulating signal.
Where,
Am → Amplitude of the modulating signal.
ωm → Angular frequency of the modulating signal.
Ɵ → Phase of the modulating signal.
Similar to amplitude modulation, when we modulate an input signal (information), we require a carrier wave:
C(t) = Ac cos(ωc t + Ɵ) ………….. 2
In angular modulation, the ωc (or) Ɵ of the carrier wave varies linearly in relation to the modulating signal, much like amplitude modulation.
You can easily download the Frequency Modulation PDF using the link given below.
