Not sure if this needs to go into education section
or antenna question but here is the question:
Question:Yagi
Antenna Gain = 10dbi
Front to back ratio = 15
db
Distance between Tx and Rx = 15KM
Frequency
= 10 MHz
Transmitter ERP = 100KW
Rx feedline
loss = 2db
Calculate Signal power supplied
to Rx if the antenna is:
a. Pointed directly
towards the transmitting antenna
b. Pointed directly
away from the transmitting antenna
This is what I've done
I calculated
free space path loss using the equation
FSPL(dB)
= 20logd + 20logf + 32.45 (where d = distance in
KM and F = Frequency in MHz)
FSPL = 23.5
+ 20 + 32.45 = 75.95dB
Rx Feedline Loss =
2dB
Total Loss = 77.95
Antenna Gain
= 10dBi
Net loss = 77.95 -10 = 66.95dBi
Tx Power = 100 KW
10 Log (Rx Power/ Tx
Power) = -66.95dBi
Rx Power = 20.18mW
But given answer
is 414uW
So what am I doing wrong
here?
Thanks