HP 5091-8686E free download

File name 5091-8686E.pdf

Agilent PN 89400-10 Time-Capture Capabilities of the Agilent 89400 Series Vector Signal Analyzers Product Note Figure 1. Simplified block diagram showing basic signal flow in the Agilent 89400 Series VSAs Introduction FFT, demodulation, or averaging. The ability to perform signal analysis When measuring a burst communica- When using time capture, the instru- separately from signal acquisition gives tions transmission or other nonsta- ment collects a (possibly) much larger the user some significant advantages. tionary signal, it is often necessary to number of samples and stores them Foremost is the ability to analyze the observe or analyze the signal for a sig- to memory, but does not perform the signal in many different ways after nificant period of time to adequately analysis immediately. Instead, the the data has been collected. Another characterize it. The Agilent Technologies user can choose the type of analysis advantage is that the data record has 89400 Series vector signal analyzers to be performed at a later time. no gaps in it. The instrument collects (VSAs) feature a time-capture capabil- the data in one time-continuous block. ity that enables the user to collect up To understand how time-capture (When using measure from input, there to 1 Msample of data at a time and works in the 89400 Series VSAs, refer is a short period of time when the ana- later choose what type of analysis to to the instrument block diagram in lysis is being performed on the time perform on the data. Figure 1. The process involves two record that has just been collected. principal events: data acquisition and While this period of time is small, Measurements can be done in one of analysis. During data acquisition the there still may be some data missed.) two ways: measure from input and signal is conditioned, sampled, and time capture. When using measure converted into a stream of digital val- from input, the instrument collects a ues that are stored in the sample block or record of samples and per- RAM. During analysis, a coordinate forms the analysis immediately. This transform is applied to the digital val- analysis may involve performing an ues and the data is scaled for display. The remainder of this paper describes Set the center frequency and span This is often referred to as a cardinal setting up time-capture measurements, The frequency span should