Occupied Bandwidth Measurement Concepts; Purpose; Measurement Method - Keysight X Series Measurement Manual

Concepts

Occupied Bandwidth Measurement Concepts

Occupied Bandwidth Measurement Concepts

Purpose

Occupied bandwidth measures the bandwidth containing 99.0 of the total
transmission power.
The spectrum shape of a signal can give useful qualitative insight into transmitter
operation. Any distortion to the spectrum shape can indicate problems in transmitter
performance.

Measurement method

The instrument uses digital signal processing (DSP) to sample the input signal and
convert it to the frequency domain. With the instrument tuned to a fixed center
frequency, samples are digitized at a high rate with DSP hardware, and then
converted to the frequency domain with FFT software.
The total absolute power within the measurement frequency span is integrated for its
100% of power. The lower and upper frequencies containing 0.5% each of the total
power are then calculated to get 99.0% bandwidth.
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