Text preview for : WebcastQA_18July2013 Vector Modulation and Frequency Conversion Fundamentals Webcast Q&A c20130722 [ part of
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Vector Modulation and Frequency Conversion Fundamentals
Webcast questions and answers July 18, 2013
John Hansen, Agilent Technologies
1) Q: If you want to measure the noise floor of an IQ Modulator, can you use a signal source analyzer
such as E5052 or will that only give you the phase component of the output noise?
A: The E5052B Signal Source Analyzer can measure the AM noise in addition to the phase noise.
www.agilent.com/find/SSA
2) Q: What is the effect of frequency error? What is the negligible error for EVM degradation for an
OFDM signal with 15 kHz subcarrier spacing?
A: Frequency error are not much of an issue in IQ modulator as the LO signal is split from the same
source. EVM degradation depends on multiple things about the OFDM waveform including guard
time between symbols and the modulation format used.
3) Q: Does the Interpolator preserve the phase reference if trying to maintain coherency?
A: Yes is does.
4) Q: What is the diff between the S1 and S2 inputs?
A: When "Mux" is selected on the front panel of the PSG signal generator you are given options on
how the IQ paths are to be routed. S1 and S2 allow routing of the external narrow band IQ inputs
(50 or 600 ohm