Product specifications

PNA-X IF paths

Figure 7 shows the PNA-X receiver/IF path block diagram with internal pulse

generators and modulators. The narrowband filter path employs a crystal filter

with 30 kHz bandwidth centered at 10.7 MHz for better signal selectivity, and

also adds receiver gating capability for narrowband pulse measurements. Earlier

PNA-X models had 60 MSa/s analog-to-digital converters (ADC) with 60 MHz

system clock (DSP version 4), later versions have been upgraded to 100 MSa/s

ADC with 100 MHz system clock (DSP version 5).

Figure 7. PNA-X IF path block diagram

Internal pulse generators

The PNA-X with internal pulse generators (Option 025) adds four pulse genera-

tors (P1, P2, P3, and P4) and an additional pulse generator (P0) that is used for

synchronizing the data acquisition. These internal pulse generators can be trig-

gered internally or externally – all at the same time. They can have an individual

delay up to 35 s, and pulse width up to 10 s. When triggered internally, the

pulse generators output a continuous pulse train with specified periods up to

35 s. The minimum timing resolution of all pulse generators is based on the

clock, 16.7 ns with DSP version 4 and 10 ns with DSP version 5. P1 through

P4 pulse generators are used to drive internal pulse modulators, IF gates and/

or external devices, such as pulsed-bias switches. P0 pulse generator is used

to trigger the DSP for data acquisition. When P0 outputs a pulse, the DSP

starts data acquisition and continues until it completes the required number of

samples per specified IF bandwidth. If P0 outputs the next pulse before the DSP

completes the data acquisition, the P0 pulse is ignored. Approximate data acqui-

sition time is 1/(IF bandwidth).