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11 I/Q Analyzer Mode
200
IDA - 3106 Narda
11.1 About I⁄Q Analyzer mode
Measurement method:
In
I⁄Q Analyzer
mode, the IDA - 3106 measures a pre-selected frequency
selectively using the selected channel bandwidth (CBW) (Zero Span
operation). Only the I/Q data resulting from the complex output signal of a
base-band demodulation are obtained; this is referred to as I/Q
demodulation. The I (in phase demodulated signal) and Q (quadrature
demodulated signal) components can describe a complex input signal
completely.
Recording and saving measurement data:
I/Q data are measured either in
Free Run
mode or triggered by an event. All
the signal information is captured without gaps during I/Q demodulation.
Even extremely short duration signals in the nanosecond range can be
detected and captured with high resolution of up to 250,000 data pairs for I
and Q. This representation of a signal sequence is retained completely
without data compression even after the measurement data is saved. Only
the raw I/Q data is saved in every case.
Analyzing and displaying measurement data:
Various types of view are provided for effective evaluation and signal
analysis, all of which are produced by computation from the measured raw
I/Q data. Once captured, the I/Q data provide users with comprehensive
analysis facilities. You can switch between the time and frequency domains
at will, and the FFT analysis parameters can be subsequently optimized.
The measurement is interrupted to perform frequency domain
transformation (FFT). In extreme cases, this can take several seconds in
order to compute the up to 7805 spectrums and display them as a
spectrogram or digital persistence spectrum. The gapless spectrogram with
its fine time resolution of down to 1 µs is a particularly powerful tool for
interference searching.
Using I/Q Streaming:
On-line signal monitoring can be done over as long a period as you like with
gapless I/Q streaming. I/Q streaming with a channel bandwidth of up to 400
kHz is supported by the Ethernet interface in remote controlled operation.
You can find more information about this in the Command Reference Guide
(see IDA Tools CD).