## An AM receiver is tuned to broadcast station at 600 kHz. Calculate the image rejection in…

1. An AM receiver is tuned to broadcast station at 600 kHz.
Calculate the image rejection in dB, assuming that the input filter
consist of one tuned circuit with a Q of 40?
2. An SSB system transmit a peak envelope power of 100 W into a 75
ohms load. The carrier signal is modulated by two tones, with
frequencies 2 kHz and 3 kHz with equal magnitude and only the lower
sideband is transmitted with a suppressed carrier. Determine the
average power into the load?
3. In the SSB, determine the maximum suppression of the unwanted
sideband if the deviation from a perfect 90 phase shift is 5”?
4. An AM transmitter has an output power of 100 W at no modulation
with efficiency of 60 %. What will be the output power with 97 %
modulation?
5. Given an audio power of 500 W which will modulated an RF
amplifier to 50 % modulate an RF amplifier to 50 % modulation. Find
the DC power input?
6. A CB transmitter supplies a total power of 120 W to an aerial.
Suppose the carrier is amplitude modulated to a depth of 80 %, how
much power is wasted by the carrier signal?
7. Determine the modulation index of the signal given the
following parameters: Emax = 10 Vp, Em= 4 Vp.
8. A DSB-SC system must suppress the carrier by 50 dB for its
original value of 10 W. To what value must the carrier be
reduced?
9. A transistor has a power dissipation rating of 30 W. Assuming
that the transistor is the only element that dissipates power in a
circuit, calculate the power an amplifier, using this transistor,
could deliver the load if it operates as Class-A wit an efficiency
of 30 %?
10. An AM signal supplies 150 W of carrier power when it is
modulated by a single sine wave to a depth of 70 %. Suppose the
total transmitted power increases by 10 % when another sine wave
simultaneously amplitude modulates the carrier, determine the
modulation index of the second sine wave?