Tektronix RSA6100A Series, Help Manual

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Reference > Connecting Signals Digital I/Q Output
Digital I/Q Output
The Real-time Digital I/Q Output is a means for the you to obtain the spectrum analyzer digital baseband
I/Q signals in a real-time data stream. This output enables you to use the spectrum analyzer as a
down-converter and then pass the down-converted baseband I/Q signals to external equipment for either
additional processing or storage.
IQ Outputs
Connect to the IQ output signals on the rear panel of the spectrum analyzer. The rear panel connectors
are LVDS connectors. For full details on the connectors, see the
RSA6100A Series Speci fi cations
and Performance Veri fi cation Technical Reference , part number 077-0251-XX. A PDF fi le of the
manual is located on the Documents CD that shipped with your instrument. If you do not have
access to the Documents CD, a PDF of the manual can be downloaded from the Tektronix Web site,
www.tektronix.com/manuals .
NOTE.
The IQ and IF outputs are disabled when an alignment is running.
Analog IF Output
The Analog IF Output is a means for you to observe the spectrum analyzer analog IF signal with an
oscilloscope.
The output level is ampli fi ed and fi ltered especially for use with oscilloscopes. The output frequency varies
with changes in center frequency of the instrument. Additionally, the output spectrum of the IF is inverted
from the input spectrum to the instrument. This means that a signal above the center frequency of the
input will be converted to a frequency below the center of the IF. The output-frequency variations and
spectral inversion makes the IF output unsuitable for use with receivers.
The IF bandwidth can be switched between 150 MHz (wide open) and 60 MHz (Gaussian-shaped to
–12 dB). The ‘wide-open’ selection will result in the fastest transient response for measurement of rapidly
changing levels such as pulse rise times. However, the 150 MHz
fi lter may create signi fi cant overshoot
and ringing in the output signal. To control transient responses, a 60 MHz fi lter with an approximately
Gaussian shape is available. Selection of the 60 MHz fi lter reduces IF-induced overshoot to less than
approximately 5% for a rectangular-shaped input envelope.
NOTE.
Spectral inversion is performed in the IF conversion process. Signals above the center frequency of
the instrument will appear below the center frequency of the IF output.
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RSA6100A Series Real-Time Spectrum Analyzers Help