Some Ultawideband/Time Domain experiments
- starting off analysing
my ancient Kathrein antenna feedline Time Domain Reflectometer with the
office
laboratory Tektronix oscilloscope
- here is a zoomed
in view of the pulse shape, very nice form, but also very slow
rise/falltime characteristics - and zoomed in even further here
- this is a really nice scope - I use it at work for RF stuff and
detecting very fast phenomena - here is a scope plot of a 2.5
GHz RF carrier from my generator
- there is even an UWB option available and this is what the spectral
distribution of the TDR pulse looks like
- so now that I had a refence of sorts, I put together a PRBS data
modulated UWB source using a Step Recovery Diode, here is the
first pulse
screenshot
- here you may see the spectral energy
distribution of this UWB signal carrying 2 Mbit/s data
- fiddling around with the circuitry I managed to somewhat
improve the pulse shape, in particular I like the 1 Ts/s repetetive
sampling rate indicated in the lower righthand corner :-)
- and here we have the limited UWB analysis option screen showing
the spectral energy
distribution for this source prototype (average and one single
point overlayed)
- and the UWB power distribution analysis for this improved time
domain pulse train and a different modulation scheme also
- pretty fun stuff - the currect circuitry also now has a
synchronous balanced sampler.... ;-)
Updated 17.06.2008/OH2AUE
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