principle communication enginering

1. 1
Superheterodyne Receiver - Problems
1. A super heterodyne receiver is used to receive an FM signal in the range of 88
MHz-108 MHz with IF frequency 10 MHz. In order to avoid image frequency,
what will be the maximum and minimum capacitance ratio at the local oscillator
section . (high side tuned is used)?
2. A super heterodyne receiver is designed to receive transmitted signals between 5
and 10MHz. what will be the tuning range of the local oscillate for IF
frequency 600kHz for high-side tuning?
3. In a super heterodyne receiver, the IF is 455kHz. If it is tuned 1200kHz, the
image frequency will be________

2. 2
In an AM super heterodyne receiver that local oscillator frequency of the mixer is
set at the higher of the two possible values, such that fLO>fc always. The
intermediate frequency (IF) of the receiver is 450 kHz and the receiver is tuned to a
station carrier frequency of 600kHz. If the RF amplifier is failed to reject the
image frequency and the loaded quality factor of the RF amplifier is 100, then the
image rejection ratio of the receiver at the selected station frequency will
be_______