Product specifications

The Option 008 pulsed-RF measurement uses narrowband detection

method for a pulse width narrower than 267 ns in standard pulse (point-in-

pulse) measurements and 1.6 us pulse width or narrower in pulse profile

measurements. When narrowband detection is selected, each receiver gate

width and delay can be controlled independently. The PNA-X narrowband

pulse implementation employs unique hardware and software techniques –

narrowband filter path, software gating, and digital filter nulling, all of which

improve the receiver sensitivity and the measurement throughput.

Narrowband filter path with crystal filter

The narrowband filter path consists of three major elements; an amplifier,

receiver gate switches, and a 30 kHz crystal filter centered at 10.7 MHz as

shown in Figure 17. The basic idea is to amplify the signal as much as possible

from the upstream receiver path before the IF gate. The levels are such that the

IF gate does not compress and the peak pulse envelop energy passes relatively

unchanged, the IF gate is then used for time discrimination. The crystal filter

removes the undesirable portion of the pulse spectrum before reaching the

downstream amplifiers and digitizer. As a result, it reduces the overall energy of

the pulsed spectrum avoiding the center spectral component to be compressed

by the ADC. The larger the duty cycle and smaller the pulse width (as the pulse

spectrum spreads out) the crystal filter contributes more to the sensitivity

improvement.

Figure 17. Narrowband filter path

PNA-X narrowband pulse

measurements