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kring_c14
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this is our last quiz on communication.. fortunately, the whole class got zero on this quiz so the professor arranged a retake and made it a take home exam instead.. this is my last hope on passing the course.. so any help would be greatly appreciated..
1.A superheterodyne receiver having an RF amplifier and an IF of 450 kHz is tuned to 15Mhz. Calculate the Qs of the RF and mixer input tuned circuits, both being the same, if the receiver's image rejection is to be 120
2. WHen a superheterodyne receiver is tuned to 555 kHZ, its local oscillator provides the mixer with an input at 1010 kHZ. What is the image frequency? The antenna of this receiver is connected to the mixer via tuned circuit whose loaded Q is 40. What will be the rejection ratio for the calculated image frequency?
3.Calculate the image frequency rejection of a double conversion receiver which has a first IF of 2 MHz and a second IF of 200 kHz, an RF amplifier whose tuned circuit has a Q of 75 (the same as that of the mixer) and which is tuned to a 30 Mhz signal. The answer is to given in decibels.
4. Caculate the image rejection of the receiver having an RF amplifier and an IF of 450 kHz., if the Qs of the relevant coils are 65, at an incoming frequency of
a.) 1200kHz
b.) 20 Mhz
Formulas are:
fi-image frequency
fs-desired signal frequency
fIF-intermediate frequency
fi = fs[tex]\stackrel{+}{-}[/tex] 2fIF
IFRR-image freq. ratio
IFRR=[tex]\sqrt{1+Q^{2}p^{2}}[/tex]
p=[tex]\frac{fi}{fs}[/tex]-[tex]\frac{fs}{fi}[/tex]
These are the only formulas on my notes.. i have difficulty identifying which frequency is which particularly the tuned frequency..is the tuned frequency the desired frequency, or intermediate frequency?
1.A superheterodyne receiver having an RF amplifier and an IF of 450 kHz is tuned to 15Mhz. Calculate the Qs of the RF and mixer input tuned circuits, both being the same, if the receiver's image rejection is to be 120
2. WHen a superheterodyne receiver is tuned to 555 kHZ, its local oscillator provides the mixer with an input at 1010 kHZ. What is the image frequency? The antenna of this receiver is connected to the mixer via tuned circuit whose loaded Q is 40. What will be the rejection ratio for the calculated image frequency?
3.Calculate the image frequency rejection of a double conversion receiver which has a first IF of 2 MHz and a second IF of 200 kHz, an RF amplifier whose tuned circuit has a Q of 75 (the same as that of the mixer) and which is tuned to a 30 Mhz signal. The answer is to given in decibels.
4. Caculate the image rejection of the receiver having an RF amplifier and an IF of 450 kHz., if the Qs of the relevant coils are 65, at an incoming frequency of
a.) 1200kHz
b.) 20 Mhz
Formulas are:
fi-image frequency
fs-desired signal frequency
fIF-intermediate frequency
fi = fs[tex]\stackrel{+}{-}[/tex] 2fIF
IFRR-image freq. ratio
IFRR=[tex]\sqrt{1+Q^{2}p^{2}}[/tex]
p=[tex]\frac{fi}{fs}[/tex]-[tex]\frac{fs}{fi}[/tex]
These are the only formulas on my notes.. i have difficulty identifying which frequency is which particularly the tuned frequency..is the tuned frequency the desired frequency, or intermediate frequency?