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Old February 28th 06, 08:25 PM posted to rec.radio.amateur.antenna
Bob Bob
 
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Default About dipoles and current/voltage nodes

Yes I should know this.. However an issue has come up in my place of
work I am trying to get my head around. On a 10GHz microwave TX there is
a stripline parallel to the output track that is suppose to detect
forward power. Nothing strange about that. What is weird is that it
appears to be roughly a half wave length (or more).

The question is this. If one hangs a 1/2 wave dipole in free space I
assume it receives such that current maximums are at the centre and
voltage maxiums at the ends. Is this the case whether a feedline is
connected or not?

If I then take a stripline cct terminated at one end with a 50r resistor
and a detect diode at the other and is a half wave long, what is the
current/voltage distribution in this configuration.

What I wonder is if it is a halfwave there may be no voltage at the
detect diode input. (It could be 3/4 wavelength when one factors in pcb
dielectric and end loading)

Thoughts?

Cheers Bob VK2YQA