Specifications

11
PNA-X’s narrowband detection method used for narrow pulse
widths (< 267 ns) employs special hardware and patented
software-gating techniques to improve system dynamic
range for low duty cycle measurements by 40 dB compared
to PNA-based pulsed-RF systems.
Using receiver leveling improves the pulsed-RF power
accuracy from +/- 1 dB to less than 0.05 dB.
Above measurements compare the results with and without
receiver leveling in GCA measurements. Inaccurate stimulus
causes large errors in power-dependent measurements such
as input and output power at the compression point versus
frequency.
The PNA-X accurately characterizes active devices under pulsed
operation with a single set of connections to the DUT—pulsed
S-parameters, pulse profile (input and output power in the
time domain), gain compression versus frequency, and swept-
frequency IMD are measured in this example.
Tips from the experts
• Compared to sweep averaging, point averaging typically
provides faster results when averaging is needed
to lower noise and improve accuracy of measurements
using wideband detection.
• During source power calibrations, power sensors read the
average power, while the analyzer sets the peak power
of the pulsed stimulus. To compensate for the difference
between the peak and average power, use the power
offset feature with the value of 10 log (duty cycle).
• The minimum pulse width for point-in-pulse measure-
ments using wideband detection is determined by the
number of samples required for the IF bandwidth (IFBW).
For example, the minimum pulse width is 100 ns with
15 MHz IFBW, 300 ns with 5 MHz IFBW, and 1.44 µs with
1 MHz IFBW. When working at the minimum pulse width
for a particular IFBW, it is important to precisely set
the measurement delay (with 10 ns resolution) to align
the pulse modulation and the data acquisition period.
• In pulse mode, it is important to use receiver leveling
to maintain power-level accuracy for power-dependent
measurements, such as output power, compression,
and intermodulation distortion.
Output power
@ compression
Input power @ compression
R1 receiver leveling
Gain @ linear input power
Gain @
compression
Open loop