Rohde&Schwarz R&S®NRQ6 Fast Pulse Power Measurement - Application Sheet Application Sheet
R&S®NRQ6
Fast Pulse Power Measurement
Application Sheet
(;ÜàZ2)
1178824202
Version 02
R&S®NRQ6
1 Your Task
This application sheet is related to various pulse measurement tasks with the frequency selective RF power sensor R&S NRQ6. All described scenarios can be summarized under the "Don’t miss a pulse" slogan. You want to:
●
Measure the pulse power of a well-known number of RF pulses.
●
Determine the energy content of a well-known number of RF pulses.
●
Count a random/unknown number of RF pulses without missing a single pulse over
a long period of time.
2 Possible Solution
The R&S NRQ6 frequency selective power sensor is designed to measure RF power in
a wide dynamic range. With its high acquisition speed, large internal memory and
sophisticated internal trigger, the R&S NRQ6 is qualified for reliably measure the power
of every single pulse of a random pulse train. As long as certain key data is observed,
the R&S NRQ6 is an ideal solution to measure pulse power over a relatively long
period. The "Don’t miss a pulse" target is met when the parameters of a pulse
sequence meet the following conditions:
Your Task
Pulse period ≥ 2 µs
Number of pulses < 128000
Pulse width ≥ 300 ns
RF level ≥ -68 dBm
These values are chosen to measure the roof power of every pulse with an uncertainty
of < 1 dB. Chapter 4, "Possible Extensions", on page 6 describes measurement setups where the main attention does not lie on a highly accurate pulse power measurement but (only) on the recognition of pulses. In such cases, the above specifications for
the pulse width can be much lower, for example, down to 70 ns.
3 How to Configure the R&S NRQ6
Prerequisites
We assume that the R&S NRQ6 has been connected to an appropriate PoE+ Ethernet
switch and the network parameters are successfully configured.
The communication between a controlling host and the sensor can take place in any
high-level language. For the sake of convenience, this application sheet only shows
the transmitted SCPI commands.
2Application Sheet 1178.8242.02 ─ 02
R&S®NRQ6
How to Configure the R&S NRQ6
There is a suite of sample programs which go along with this application sheet. The
programming examples come with full source code and are implemented both in
Python and C/C++. On an MS Windows system, see the subfolders of
C:\ProgramData\Rohde-Schwarz\NRP-Toolkit-SDK\NRQ\ for the
DontMissAPulse examples.
Scenario 1
Measurement of settled pulse roof power. The parameters are chosen for acquiring 1
or more samples in the roof of a pulse. For this pulse power measurement, the 25 MHz
NORMAL or 40 MHz FLAT resolution bandwidth filter is selected. Trigger is internal on
the rising edge, selected trigger level approx. 2 dB to 3 dB below the expected pulse
power. Not to include (parts of) the rising edge in the measurement, a 150 ns delay is
chosen after the trigger condition. With a pulse width of approx. 400 ns, an aperture
time of 120 ns to 150 ns is reasonable to exclude any parts of the falling edge of the
pulse.
Given that our pulses are at an RF of 2.4 GHz, the R&S NRQ6 is prepared with the
following commands:
*RST # Reset the power sensor
*CLS # Clear Status subsystem
*IDN? # Query device identification (optional)
SENS:FUNC "POW:AVG" # Select power average measurement mode
SENS:FREQ 2.4e9 # RF = 2.4 GHz
SENS:BAND:RES:TYPE:AUTO OFF # Configuring resolution bandwidth filter
SENS:BAND:RES:TYPE NORMAL # Manual selection for 25 MHz NORMAL filter
SENS:BAND:RES 25.0e6 # ::
SENS:INP:ATT:AUTO OFF # De-activation of input attenuation
SENS:INP:ATT 0 # ::
TRIG:SOUR INT # Internal trigger
TRIG:LEV -68 DBM # @ -68 dBm
TRIG:DEL 150.0e-9 # Mask rising edge & possible overshoot
SENS:POW:AVG:APER 120.0e-9 # Measurement window length 120 ns
BUFF:STAT ON # We expect 95000 pulses...
3Application Sheet 1178.8242.02 ─ 02
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