Specifications

Chapter 8
Time Domain
8-1 INTRODUCTION This chapter describes the optional Time Domain feature.
8-2 TIME DOMAIN
MEASUREMENTS
The Option 2, Time Domain feature provides a useful measurement
tool for determining the location of impedance discontinuities. Some
typical applications are identifying and analyzing circuit elements,
isolating and analyzing a desired response, locating faults in cables,
and measuring antennas.
The relationship between the frequency-domain response and the
time-domain response of a network is described mathematically by the
Fourier transform.
The MS462XX makes measurements in the frequency domain then
calculates the inverse Fourier transform to give the time-domain
response. The time-domain response is displayed as a function of time
(or distance). This computational technique benefits from the wide
dynamic range and the error correction of the frequency-domain data.
Let us examine the time-domain capabilities. Two measurement
modes are available: lowpass and bandpass.
We use the lowpass mode with devices that have a dc or low-frequency
response. In the lowpass mode two responses to the device-under-test
(DUT) are available: impulse or step response.
The frequencies used for the test must be harmonically related
(integer multiples) to the start frequency. The simplest way to
calculate this relationship is to divide the highest frequency in the
calibration by 1600 (the default number-of-points available); this is the
start frequency. For example if the highest frequency is 6 GHz, the
calculated start frequency is 3.75MHz (6/1600).
MS462XX OM 8-3
TIME DOMAIN
A USEFUL TOOL FOR:
l
Identifying and Analyzing Circuit
Elements
l Isolating a Desired Response
l Locating Faults
l Making Antenna Measurements
MS462XX TIME DOMAIN MODES
l
Lowpass Mode
l
Bandpass Mode
LOWPASS MODE
l
Either Impulse or Step Response
Available
l
Displays Impedance Information
l
Requires Harmonically Related
Frequencies
l
Used When Device Has a DC or
Low Frequency Path