How Does Changing Distance Affect Microwave Path Difference?

AI Thread Summary
Changing the distance of H from the source affects the path difference, which in turn influences the phase difference according to the equation (path difference)/wavelength x 2pi. Minima refers to points of destructive interference, which occurs at zero amplitude when equal amplitude waves interfere, but a path difference of lambda/2 does not guarantee zero amplitude if the amplitudes are not equal. The discussion also touches on the Doppler effect, highlighting its relevance to understanding frequency changes in reflections from a moving plate. Participants encourage exploring the concept of Doppler radar to better grasp the problem at hand. Overall, the conversation emphasizes the importance of understanding wave interference and the Doppler effect in microwave applications.
heroslayer99
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Homework Statement
Show that the student is correct.
Relevant Equations
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I understand the equation (path difference)/wavelength x 2pi = phase difference, but in this case I do not know how changing the distance of H from the source will affect the path difference. In addition to this, does minima refer to 0 amplitude (complete destructive interference) or does minima just refer to less than maxima? Does a path difference of lambda/2 gurantee the resulting signal has 0 amplitude?
 
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Hi,

Zero amplitude can only be achieved when equal amplitude waves interfere. Here, all you are given is that H is a partial reflector.

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BvU said:
Hi,

Zero amplitude can only be achieved when equal amplitude waves interfere. Here, all you are given is that H is a partial reflector.

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Ok thanks. Any tips on how to do the question
 
heroslayer99 said:
Ok thanks. Any tips on how to do the question
What should be the received frequency of the reflections from the moving plate?
 
I dont know, 200hz?
 
heroslayer99 said:
I dont know, 200hz?
Have you never learnt about the Doppler effect with sound waves?
 
No, also aren't these microwaves
 
heroslayer99 said:
No, also aren't these microwaves
You are missing the point!

Tip: find out what 'Doppler radar' is and how it works. Then see if you can apply your new found knowledge to this problem Then ask us to check/advise.
 
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