Giga-tronics 8650B Series, Руководство по эксплуатации

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Series 8650B Universal Power Meters
3-34 Publication 31470-001, Rev C, November 2, 2017
3.2.17 Cal Factor Correction

SENSe:CORRection:FREQuency

SENSe:CORRection:VPROpf

MEMory:SELect

MEMory:FREQuency

MEMory:SLOPe
Power Sensors have a measurable frequency response. During manufacture, this response is calibrated at
predetermined frequency intervals. Instead of printing the data on the sensor label, each Giga-tronics power
sensor includes a built-in EEPROM which has been programmed with the frequency calibration factor data for
that particular power sensor.
The following SCPI commands tell the 8650B the operating frequency of the measured microwave or RF signal.
Thus, the meter automatically interpolates the correct Cal Factor and applies that value to the measurement
data. By performing this automatically, there is no need to read Cal Factor data from the side of sensor housings
and program the data into tables within the ATE programming. Except for advanced measurement techniques
using Burst Mode, there is no need to write cal factor interpolation routines; this is all done by the power meter.
As shown below, sensor Cal Factor data can be read into the computer. Also see the Sensor EEPROM Commands
in Section 3.2.34 for Cal Factor programming.
SENSe:CORRection:FREQuency
Syntax: SENSe<sensor 1 or 2>:CORRection:FREQuency[:CW-FIXed] space <frequency in Hz>
Example:
SENS2:CORR:FREQ 5E7 ! SETS SENSOR 2 FREQUENCY CORRECTION TO 50 MHZ
Description: This command sets the correction for sensor frequency response characteristics. The power
meter uses this specified frequency to automatically interpolate and apply the Cal Factor for
that sensor (computed from Cal Factor data points stored within each sensor’s EEPROM).
Unless the EEPROM has been modified subsequent to shipment, the Cal Factor is always 0.0
dB at sensor calibration frequency. Be sure to always correct for sensor frequency response
characteristics by using this frequency correction command, using automated V
PROP
F
correction, or post-correcting uncorrected measurement data in the ATE system by
downloading Cal Factor points from the sensor EEPROM remotely via the 8650B.
SENSe:CORRection:VPROpf
Syntax:
SENSe<sensor 1 or 2>:CORRection:VPROpf[:STATe] space <ON | OFF>
Example:
SENS1:CORR:VPRO ON ! ENABLES SENSOR 1 V
PROP
F FUNCTION
Description: This command enables or disables the V
PROP
F mode of frequency response correction for the
specified sensor. Before enableing, the V
PROP
F input must first be configured using the
MEMory:SELect, MEMory:FREQuency, and MEMory:SLOPe commands. Setting this control to
ON activates V
PROP
F and deactivates SENS#:CORR:FREQ #.
NOTE:
Example programs for Cal Factor Corrections are contained in Appendix A of this publication.