Quick Answer: How Does FM Demodulator Work?

What is difference between modulation and demodulation?

Modulation is the process of influencing data information on the carrier, while demodulation is the recovery of original information at the distant end from the carrier.

A modem is an equipment that performs both modulation and demodulation..

Why is modulation needed?

Modulation allows us to send a signal over a bandpass frequency range. If every signal gets its own frequency range, then we can transmit multiple signals simultaneously over a single channel, all using different frequency ranges. Another reason to modulate a signal is to allow the use of a smaller antenna.

What is modulation in simple words?

Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal. … Modulation is usually applied to electromagnetic signals: radio waves, lasers/optics and computer networks.

What are the types of FM?

There are different types of FM demodulators including:Slope Detector.Foster-Seeley Discriminator.Ratio Detector.Pulse-Averaging Discriminators.Quadrature Detectors.Phase-Locked Loops.

What is the main disadvantage of FM over AM?

What is the main disadvantage of FM over AM? Explanation: The disadvantage of FM over AM is that in frequency modulation large bandwidth is required. While, in case of advantages, FM is less prone to noise interference and has lower power consumption compared to AM.

How do you demodulate FM?

A simple and effective FM demodulation technique involves a high-pass filter (for FM-to-AM conversion) followed by an AM demodulator. A high-pass-filter-based FM demodulator is preceded by a limiter to prevent amplitude variations from contributing error to the demodulated signal.

What is an example of modulation?

For example, a held F from a section in B♭ major could be used to transition to F major. This is used, for example, in Schubert’s Unfinished Symphony. “If all of the notes in the chord are common to both scales (major or minor), then we call it a common chord modulation.

Is PLL analog or digital?

The digital PLL can handle clock switching and difficult frequency ratios, while the analogue one can be used to further attenuate spurs, multiply to higher frequencies, and perform clock distribution.

How a PLL is used as an FM demodulator?

In radio transmitters, a PLL is used to synthesize new frequencies which are a multiple of a reference frequency, with the same stability as the reference frequency. Demodulation of frequency modulation (FM): If PLL is locked to a FM signal, the VCO tracks the instantaneous frequency of the input signal.

What circuit is used for FM demodulation?

Phase Locked LoopThe FM demodulator is done with the help of a circuit called Phase Locked Loop (PLL). A PLL should have basic functional blocks like Voltage Controlled Oscillator (VCO), Phase comparator, Low Pass Filter (LPF) and Source follower.

What is the process of demodulation?

The process of separating the original information or SIGNAL from the MODULATED CARRIER. In the case of AMPLITUDE or FREQUENCY MODULATION it involves a device, called a demodulator or detector, which produces a signal corresponding to the instantaneous changes in amplitude or frequency, respectively.

Which is better AM or FM?

AM has poorer sound quality compared with FM, but is cheaper and can be transmitted over long distances. It has a lower bandwidth so it can have more stations available in any frequency range. FM is less prone to interference than AM. However, FM signals are impacted by physical barriers.

What are the two main types of modulation techniques?

Modulation techniques are roughly divided into four types: Analog modulation, Digital modulation, Pulse modulation , and Spread spectrum method. Analog modulation is typically used for AM, FM radio, and short-wave broadcasting. Digital modulation involves transmission of binary signals (0 and 1).

What are the disadvantages of AM?

Disadvantages of Amplitude Modulation:An amplitude modulation signal is not efficient in terms of its power usage. … It is not efficient in terms of its use of bandwidth. … AM detectors are sensitive to noise hence an amplitude modulation signal is prone to high levels of noise.Reproduction is not high fidelity.

What is the function of the demodulator?

A demodulator is a circuit that is used in amplitude modulation and frequency modulation receivers in order to separate the information that was modulated onto the carrier from the carrier itself. A demodulator is the analog part of the modulator.

Why do we use PLL?

The main purpose of a PLL circuit is to synchronize an output oscillator signal with a reference signal. When the phase difference between the two signals is zero, the system is “locked.” A PLL is a closed-loop system with a control mechanism to reduce any phase error that may occur.

Which is the best modulation technique?

Amplitude modulation methods like ASK/OOK and QAM are far more susceptible to noise so they have a higher BER for a given modulation. Phase and frequency modulation (BPSK, FSK, etc.) fare better in a noisy environment so they require less signal power for a given noise level (Fig.

What is free running frequency?

The VCO is a special type of oscillator that has a frequency controlled by an applied voltage. The frequency of the VCO without any control signal applied is called the free- running frequency, f0. … The high frequency of the sum product at fA + fB is not suitable as a VCO control volt- age and so must be removed.