Sunday, March 3, 2013

Agilent's New RTSA Capability on its PXA Signal Analyzers

In this post I wanted to share the new real-time spectrum analysis (RTSA) feature that Agilent added to its PXA line of high performance signal analyzers. The RTSA feature gives the signal analyzer the ability to continuously capture spectra without any dead time between acquisitions. The PXA's maximum capture rate is 3.57us so that means it has a probability of intercept of 100% for signals with a duration of 3.57us or more. This feature is incredibly useful when trying to analyze intermittent or dynamic signals such as those used in radar and electronic warfare applications.

Let me give a quick explanation of what "dead time" means when referring to instruments like scopes, counters, and signal analyzers. When one of the example instruments makes a measurement or acquisition it then displays the results and prepares to make another measurement. The time in between two consecutive measurements (sometimes referred to as re-arm time) is dead time because no measurement is being made. Often, especially in the case of scopes, the dead time is longer then the measurement or acquisition time so any changes that the signal goes through during the dead time is not captured or measured by the instrument. When an instrument such as a signal analyzer has continuous or gap-free measurement capability it has no dead time time between acquisitions it simply continuously acquires data at its set sample or rate.

With the addition of the RTSA capability the PXA also added some advanced display capabilities to show the continuously captured data in a useful easy to interpret way to users. This includes a display persistence setting, mask testing, a histogram display, and a spectra versus time display. Below is an example of a frequency hopping radar signal displayed using the persistence and mask testing capability.

Besides the new RTSA option capability the PXA signal analyzer line includes a number of industry leading specs and features including:
  • –157 dBm at 10 GHz average noise floor which ensures low level signals do not get lost in the "grass"
  • 160-MHz real-time bandwidth for looking at wide-band modulated signals
  • up to 75 dB spurious-free dynamic range to see small signals in the presence of large ones
If you have any questions from this post feel free to email me and if you have anything to add use the comments section below.

Update (1/30/14) - Agilent RTSA recorder and analyzer application released:
Agilent has released the new RTSA spectrum recorder and analyzer application (available as Agilent RTSA option RTR) that allows you to directly record spectrum signal data on the RTSA signal analyzer itself, and then immediately play back the recording to look for signal anomalies. The option includes the application example (delivered as a MATLAB App), modifiable source code, and a MATLAB software license to execute and modify it. You can learn more about using this RTSA application and the option’s contents in my Agilent RTSA recorder blog entry.

For more information on the new RTSA feature on the PXA click here