Atec Agilent-ECP-E26A User Manual
Page 24
1
Introduction
8
Agilent E4412A and E4413A Power Sensors Operating and Service Guide
EXAMPLE A (Amplifier Gain Measurement):
Input power (reference) = –35 dBm; power measured = +6 dBm’ so the relative
gain is +41 dB. the chart indicates a typical error of ±6 %, which corresponds
to +0.25 dB/–0.27 dB uncertainty in the gain measurement.
EXAMPLE B (Insertion Loss Measurement):
Reference power = –25 dBm; power measured = –35 dBm, for the case of an
insertion loss of 10 dB. the chart indicates a typical error of ±1 %, which
corresponds to ±0.04 dBm uncertainty in the measurement.
Calibration Factor (CF) and Reflection Coefficient (Rho)
Calibration factor and reflection coefficient data are given at 1 GHz
increments on a data sheet included with the power sensor. This data is
unique to each sensor. If you have more than one sensor, match the serial
number on the data sheet with the serial number on the power sensor you are
using. The CF corrects for the frequency response of the sensor. The power
meter automatically reads the CF data stored in the sensor and uses it to make
the corrections.
Reflection Coefficie
nt
(Rho, or
r) relates to SWR according to the following
formula:
SWR = (1+
r)/(1- r)
Typical uncertainties of the CF data are listed in
for the E4412A
for the E4413A power sensor. The uncertainty
analysis for the calibration of the sensors was done in accordance with the
ISO/TAG4 Guide. The uncertainty data reported on the calibration certificate
is the expanded uncertainty with 95% confidence level and a coverage factor of
2.
Additionally, at frequencies other than the reference frequency, for measure-
ments above 0 dBm include 0.5 %/dB high power calibration factor uncer-
tainty.