Galilea wrote:
I can understand all you are saying but in this case it is am impulsive
wideband signal (500 - 2.5 GHz), with a defined start and finish, caused by,
say things like car ignition systems and faulty thermostats. Surely a signal
like that would have all frequency components starting and ending at a
zero-crossing and then have full cycles, wouldn't it? Or maybe not because
of the multipath effects? Do you believe this can be the case in my
situation?

Thank you.



"Galilea" wrote in message
...

Hello, thank you for reading this post.

When analysing wideband impulse signals from a wideband antenna I have
realised that the average signal magnitude is not zero. I have thought

this

is because the reactance of the antenna at different frequencies varies

and

since it is a wideband antenna there can be energy measured since it is

only

for an extremely small period of time of 2-4 us. However, I am not sure

and

would greatly appreciate the views of this newsgroup.






If the antenna is very wideband and isn't acting like a filter,
you can do a Fourier analysis on a series of pulses and decide for
yourself whether there is a DC component or not. Or, if there's only
one pulse, you can use the Fourier integral to find the amplitude
distribution across the frequency spectrum. I don't think you
should be too surprised to find a DC component in a series of
pulses, or even in a single pulse.
73,
Tom Donaly, KA6RUH