Time Gating Concepts; Introduction: Using Time Gating On A Simplified Digital Radio Signal - Keysight X Series Measurement Manual

Time Gating Concepts

Introduction: Using Time Gating on a Simplified Digital Radio Signal

This section shows you the concepts of using time gating on a simplified digital
radio signal. The section on Making Time-Gated Measurements demonstrates time
gating examples.
Figure 15-3
time-sharing a single frequency channel. Radio 1 transmits for 1 ms then radio 2
transmits for 1 ms.
Figure 15-3 Simplified Digital Mobile-Radio Signal in Time Domain
We want to measure the unique frequency spectrum of each transmitter.
A signal analyzer without time gating cannot do this. By the time the signal analyzer
has completed its measurement sweep, which lasts about 50 ms, the radio
transmissions switch back and forth 25 times. Because the radios are both
transmitting at the same frequency, their frequency spectra overlap, as shown in
Figure 15-4
which part of the spectrum results from which signal.
Figure 15-4 Frequency Spectra of the Combined Radio Signals
shows a signal with two radios, radio 1 and radio 2, that are
The signal analyzer shows the combined spectrum; you cannot tell
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Concepts
Time Gating Concepts