chapter  3
6 Superhet receivers
Pages 1

The output of the RF amplifier stage is applied

to the mixer stage. This stage combines the RF

signal with the signal derived from the local

oscillator (LO) stage in order to produce a signal

at the intermediate frequency (IF). It is worth

noting that the output signal produced by the

mixer actually contains a number of signal

components, including the sum and difference of

the signal and local oscillator frequencies as well

as the original signals plus harmonic components.

The wanted signal (i.e. that which corresponds to

the IF) is passed (usually by some form of filter-

see page 48) to the IF amplifier stage. This stage