18 | Keysight | FieldFox Handheld Analyzers 4/6.5/9/14/18/26.5/32/44/50 GHz - Data Sheet
The performance listed in TDR cable measurements, VNA time domain, mixed-mode S-parameters and vector voltmeter sections
applies to the capabilities available in the following models:
– FieldFox RF & microwave analyzers: N9913A, N9914A, N9915A, N9916A, N9917A, N9918A
N9950A, N9951A, N9952A
– FieldFox microwave vector network analyzers: N9925A, N9926A, N9927A, N9928A
See FieldFox Configuration Guide for option information. Many capabilities listed in this Data Sheet require options.
TDR Cable Measurements
The TDR cable option adds time domain reflectometry (TDR) measurements to FieldFox’s CAT mode. FieldFox’s TDR measurements are
based on an inverse Fourier transform of the frequency-domain data. TDR measurements are useful in not only identifying the location
of faults along cables, but also the nature of the fault. Resistive, inductive and capacitive faults will each have a different response.
These differences help engineers and technicians trouble-shoot line faults.
Measurements: TDR (linear rho) and TDR impedance (ohm)
Y-axis: linear (rho) or impedance (ohm)
X-axis: distance (meters or feet)
VNA Time Domain
In time-domain mode, FieldFox computes the inverse Fourier transform of the frequency-domain data to display reflection or transmis-
sion coefficients versus time.
Setup parameters
Time
Start, stop, center, span
Gating
Start, stop, center, span, and on/off
Numbers of points, velocity vector, line loss, window shape, independent control for all four traces
Time stimulus modes
Low-pass step
Low-pass step is similar to a traditional time domain reflectometer (TDR) stimulus waveform. It is used to measure
low-pass devices. The frequency-domain data should extend from DC (extrapolated value) to a higher value.
Low-pass impulse
Bandpass impulse
Low-pass impulse response is used to measure low-pass devices.
The bandpass impulse simulates a pulsed RF signal and is used to measure the time domain response of
band-limited devices.
Windows
The windowing function can be used to filter the frequency domain data and thereby reduce overshoot and ringing in the time domain response.
Windows
Minimum, medium and maximum, manual entry of Kaiser Beta and impulse width.
Gating
The gating function can be used to selectively remove reflection or transmission time domain responses. In converting back to the frequency domain the
effects of the responses outside the gate are removed. The results can be viewed with gating on and off, using two traces.
Gate types
Notch, bandpass
Gate shapes
Maximum, wide, normal, minimum