What is the function of the RF amplifier?

rf is a single tuned amplifier . Its functions are :-

1.improves selectivity ( i.e rejection of unwanted signal) , so that it prevents heterodyning which results in interference frequency.

2. improves image frequency rejection

3. improves sensitivity ( gain of amplifier )

4.improves coupling of receiver with antenna .

5. improves signal to noise ratio.

6. reradiation of local oscillator through receiver antenna is prevented