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sghaussi
May4-05, 04:58 AM
Hello, I am having difficulty answering the following problem:

consider two antennas, separated by X meters that radiate in phase at f. A reciever placed 150 m from both antennas measures an intensity I_o. The reciever is moved so that it is 1.8 m closer to one antenna than ot the other.

What is the phase difference between the two radio waves produced by the path difference?


okay. so I know i want to use the formula: phase diff = 2pi/lamda*(r_2 - r_1)

i was able to calculate lamda, however I'm not sure about the path difference. Would that be my 1.8 m?? or is there trig involved here in order to figure out r_2 - r_1 ??

OlderDan
May4-05, 06:45 AM
Hello, I am having difficulty answering the following problem:

consider two antennas, separated by X meters that radiate in phase at f. A reciever placed 150 m from both antennas measures an intensity I_o. The reciever is moved so that it is 1.8 m closer to one antenna than ot the other.

What is the phase difference between the two radio waves produced by the path difference?


okay. so I know i want to use the formula: phase diff = 2pi/lamda*(r_2 - r_1)

i was able to calculate lamda, however I'm not sure about the path difference. Would that be my 1.8 m?? or is there trig involved here in order to figure out r_2 - r_1 ??

The reciever is moved so that it is 1.8 m closer to one antenna than to the other.

sghaussi
May4-05, 07:26 AM
so does that mean it is hte path difference?

sghaussi
May4-05, 10:27 AM
do I use trig here or is hte phase difference already given?

OlderDan
May4-05, 01:31 PM
so does that mean it is hte path difference?

Do you understand what r_1 and r_2 are? They are not just letters in a formula. They represent two distances. They are:

r_1 = distance to antenna 1 from the location where you are receiving the wave

r_2 = distance to antenna 2 from the location where you are receiving the wave

If you are 1.8m closer to one antenna than you are to the other, what must r_2 - r_1 be?

You need to ponder this question until you figure out the answer. It will do you no good for someone to give you the direct answer you want about needing or not needing to apply trig.