Thank you for your reply. I see
that I did not manage o explain very well what I
wanted to do. The idea is that I want to set up
a measurement system and for characterization I
want to to measure transmission of various two port
components (amplifiers, transmission lines, etc).
Of course, I would normally use a network analyzer,
which gives both the amplitude and phase of the
transmission. The problem is that we do not have
a network analyzer. But, since we have a spectrum
analyzer, I was thinking of a different solution:
use a noise source to inject some broadband noise
at one port and the spectrum analyzer to measure
the transmitted noise at another port. This measurement
would give me the amplitude of the transmission
for that two port system (unfotunately I will still
miss the phase).
So in the end I would need a
noise source to do the measurement. The requirement
would be that it generates noise in a broadband
(say from a few MHz to a few GHz) and that it has
an output impedance which is 50 ohm over this band.
In the RF world one should have a deep pocket
for purchasing test equipment. There are no
cheap solutions for getting accurate and reliable
test results. Any compromise in the price will
come on the expense of quality
I completely agree with you.