What is the advantage of super Heterodyning?

The superheterodyne receiver offers superior sensitivity, frequency stability and selectivity. Compared with the tuned radio frequency receiver (TRF) design, superhets offer better stability because a tuneable oscillator is more easily realized than a tuneable amplifier.

What is the difference between IF and RF?

In order to clarify the difference between RF and IF amplifiers, we need to know that in most radio receiver topologies the incoming high-frequency signal is not shifted down to the baseband in a single step. RF amplifiers used at those lower frequencies are referred to as intermediate frequency (IF) amplifiers.

How does intermediate frequency work?

In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission or reception. When several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune.

What are two limitations of superheterodyne receiver?

Drawbacks or disadvantages of Superheterodyne Receiver This increases cost of overall receiver. ➨Moreover filters are also needed to remove any LO leakage as well as undesired frequency components to prevent image frequencies. This also increases cost as well as complexity of the receiver.

Why is intermediate frequency required?

The main reason for using an intermediate frequency is to improve frequency selectivity. In communication circuits, a very common task is to separate out, or extract, signals or components of a signal that are close together in frequency.

What is the function of limiter in FM receiver?

Limiter circuit is used in FM receiver to remove the noise present in the peaks of the received signal and to remove any amplitude variation in the received signal; the output of the limiter has constant amplitude.

Why is AM radio tuned to 455 kHz?

In a tunable (superhetrodyne) AM receiver, all of the amplification takes place in a two stage fixed tuned (Intermediate Frequency) amplifier. This is tuned to 455 kHz for two reasons. 1. There is no usage on air at that frequency (a strong unwanted signal on that frequency could break through causing interference).

Why is the intermediate frequency higher than the input frequency?

A first intermediate frequency may even be higher than the input signal, so that all undesired responses can be easily filtered out by a fixed-tuned RF stage. In a digital receiver, the analog-to-digital converter (ADC) operates at low sampling rates, so input RF must be mixed down to IF to be processed.

What are the most common intermediate frequencies used in radio communication?

Perhaps the most commonly used intermediate frequencies for broadcast receivers are around 455 kHz for AM receivers and 10.7 MHz for FM receivers.

How do I tune in to two stations at the same time?

This is done by a bunch of band pass filters that together, have a passband that is wide enough to cope with the signal you wish to receive but not so wide that it lets others in. Now say you wanted to tune in to 2 stations – you’d have to re-align all this filtering to coincide with a new station.