R&S FSQ Signal Analyzer - Rohde & Schwarz

R&S FSQ Getting Started
Noise Measurements
Fig. 2.14 Measurement of the R&S FSQ’s intrinsic noise power in a 1.23 MHz channel
bandwidth.
5. Stabilizing the measurement result by increasing the sweep time
➢ Press the SWEEP TIME softkey and enter 1 s.
By increasing the sweep time to 1 s, the trace becomes much smoother
thanks to the RMS detector and the channel power measurement display is
much more stable.
6. Referring the measured channel power to a bandwidth of 1 Hz
➢ Press the CHAN PWR / Hz softkey.
The channel power is referred to a bandwidth of 1 Hz. The measurement is
corrected by -10 · log (ChanBW), with ChanBW being the channel bandwidth
that was selected.
Method of calculating the channel power
When measuring the channel power, the R&S FSQ integrates the linear power
which corresponds to the levels of the pixels within the selected channel. The
R&S FSQ uses a resolution bandwidth which is far smaller than the channel bandwidth.
When sweeping over the channel, the channel filter is formed by the passband
characteristics of the resolution bandwidth (see Fig. 2.15).
Operating Manual 1313.9681.12 - 01 2.21