Rohde & Schwarz 1164.4391.03, Руководство по обслуживанию

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Instrument Design and Function Description R&S FSP
1164.4556.82 3.8 E-1
FFT Bandwidth
In the FFT bandwidth mode, the synthesizer is set to the desired frequency via the DCON which also
generates the tuning voltages for the analog hardware. The signal path is routed via ADC, Corr RAM
and DDC. The DDC first mixes the input IF into the baseband using an NCO, and then the obtained I/Q
signal is filtered in an HDF (
h igh d ecimation f ilter) and FIR stage ( f inite i mpulse r esponse). The I/Q
output data are then stored by the DDC in the I/Q RAM. With data logging completed, the I/Q data from
the I/Q RAM is transferred to the host via DDC and PCI interface FPGA. The host then performs the
FFT for this sweep section.
Video Bandwidths (VBW)
The video filters of the R&S FSP can be adjusted between 1 Hz and 10 MHz in steps of 1/3/10. They are
designed as a digital lowpass filter for the video signal. The video bandwidth can either be coupled to
the resolution bandwidth (= default setting) or manually set to a fixed value.
Detectors
The R&S FSP uses a detector for the positive peak (peak+) and one for the negative peak value
(peak-). In the sample mode, the video signal can also be directly sampled by the A/D converter without
a peak detector being required .
Quasi-Peak, Average and RMS detectors are available in addition. The
RMS detector forms the rms value of the input signal for one point in the display during the
measurement time.
AF Demodulation (Option R&S FSP-B3)
The R&S FSP may contain option R&S FSP-B3 as an AM/FM demodulator. In the analyzer mode, the
signal at the position of the reference marker during a sweep can be demodulated. In this case, the R&S
FSP stops the sweep for a selectable time and demodulates the input signal. The loudness is adjusted
with the volume control knob.
TV and RF Trigger (Option R&S FSP-B6)
By using the TV and RF trigger option R&S FSP-B6, you can set triggering to a TV signal or to the
presence of an RF signal on the R&S FSP.
For this purpose, the option module has a TV demodulator that provides the trigger signals required for
analyzing TV signals. In addition to the pure trigger function, the demodulated TV signal is available as a
CCVS video signal for operating a TV monitor. The R&S FSP can also derive the trigger signals from an
externally applied CCVS signal. The associated connector is located on the rear panel of the R&S FSP.
The R&S FSP derives different trigger signals from the video signal to display defined sections of the TV
video signal in the time domain. Triggering in response to field frequency and to each line of the TV
video signal is possible.
In addition, the option module contains a broadband RF detector (bandwidth = 80 MHz) that allows
detection of a carrier signal far from the selected frequency range. This RF power trigger will function as
long as the RF signal applied to the input mixer is between -10 dBm and -50 dBm.