Reactance modulator circuit

1. What is a reactance modulator?
2. What is the principle of a variable reactance modulator used in FM generation?
3. How FM is generated?

What is a reactance modulator?

Reactance modulators are used for the generation of frequency modulation (FM) These reactance modulators do not have very good frequency stability. But if it is to be used for broadcast applications, then it is must-have high-frequency stability. It can be achieved through a frequency stabilized reactance modulator.

What is the principle of a variable reactance modulator used in FM generation?

Reactance Modulator

For this, a device called voltage controlled oscillator (VCO) is used. A VCO can be implemented by using a sinusoidal oscillator with a tuned circuit having a high value of Q. The frequency of this oscillator is changed by changing the reactive components involved in the tuned circuit.

How FM is generated?

FM signals can be generated either by using direct frequency modulation, which is achieved by inputting a message directly into a voltage-controlled oscillator, or by using indirect frequency modulation, which is achieved by integrating a message signal to generate a phase-modulated signal, which is then used to ...