HP 8530A, Руководство по эксплуатации и программированию, Страница: 413 / 439

Glossary
Calibration, Antenna
Antenna calibration using a standard gain antenna allows measured data to be expressed in
dBi (dB relative to an isotropic radiator). A standard gain antenna with known or dened
gain values at specic frequencies is used as a transfer standard to calibrate the system.
Calibrating with a standard gain antenna corrects for the transmission response error .
Isolation calibration is also available , which corrects measurement errors caused by receiver
cross-talk.
Calibration Coecients
An internal data array . This is the correction data that was created during calibration (also
called \Cal Sets"). Y ou can retrieve the active Cal Set register over HP-IB .
Cal Denition
A calibration denition is an ASCII le you create using a text editor . It contains frequency
and gain values that were published for the standard gain antenna.
Cal Set
A nished calibration data le . During the calibration, the standard gain antenna is
measured and its response is compared to the cal denition. Any dierences are stored in
an internal \cal set register ." These dierences are the measurement osets that are used
to compute the correct gain value , expressed in dBi. Cal sets can be stored to , or loaded
from disc .
When you press 4 CAL 5
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CORRECTION ON , and then choose one of the eight cal sets , the
selected calibration data is placed in the Calibration Coecient Array for that channel.
Channel
The receiver measures the performance of the antenna under test and converts the results
into digital data. This data is then duplicated into two identical copies . Once copy becomes
\Channel 1" data and the other becomes \Channel 2" data.
When you press 4 CHANNEL 1 5 on the front panel, most instrument settings you make
afterward will aect only the Channel 1 data. When you press 4 CHANNEL 2 5 most settings
you make afterward will aect only the Channel 2 data. This feature allows you to view
two versions of the same measurement at the same time . Each version can use dierent
instrument features , but still represents the same basic measurement data. F or example:
One version might be calibrated, while the other is uncalibrated. Or , one version might
display frequency data, while the other displays Time Domain data.
Such features as calibration, time domain, display formatting, and trace math can be
performed independently on the two channels . When you press the 4
CHANNEL 1
5 or
4
CHANNEL 2
5 key , you make that channel the \active channel." Any subsequent changes you
make to measurement settings will aect that channel.
Some instrument settings are always the same in both channels . Such features are
\coupled." Other settings can be changed in one channel versus the other . Such features
are \uncoupled."
Continual Sweep Mode
When this mode is selected, the receiver makes measurements continously . This mode is
most often used in Frequency or Time Domain measurements . T o select this mode , make
sure the receiver is in Frequency or Time Domain and press:
STIMULUS 4
MENU
5
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CONTINUAL
Glossary-2