Find the image rejection in a superheterodyne receiver with

Find the image rejection in a superheterodyne receiver with fIF = 455 kHz when tuned to MHz signal. Given Q. of the preselector and RF amplifier tuned circuit each is 65—

We know that image rejection ratio, when quality factor is represented by

Image rejection ratio =

√1 + ρ²Q²

where,

ρ =	f_image	−	f_c
	f_c		f_image

Given, f_image = f_c + 2f_IF
= 30 × 10⁶ + 2 × 455 × 10³
= 30.91 × 10⁶

ρ =	30.91 × 10⁶	−	30 × 10⁶
	30 × 10⁶		30.91 × 10⁶

Image rejection ratio = √1 + (0.6)² × 65²
Image rejection ratio = √1 + (0.6)² × 65²
= √15.21
= 3.9