Agilent Technologies E4438C manual Repeatability and linearity

Specifications for Frequency and Power Characteristics

Repeatability and linearity

Repeatability	Repeatability
1900 MHz CW, 5 dBm, attenuator hold On, ALC On	1900 MHz CW, 5 dBm, attenuator hold Off, ALC Off

0.1						0.5
0.09					Typical unit	0.45
0.08					Limits	0.4
0.07						0.35
0.06						0.3
0.05						0.25
0.04						0.2
(dB)Powererror						(dB)errorPower
0.03						0.15
0.02						0.10
0.01						0.05
0						0
0	20	40	60	80	100	120

								Typical unit
								Limits
0	1	2	3	4	5	6	7	8	9	10

Elapsed time (minutes) Elapsed time (minutes)

Repeatability measures the ability of the instrument to return to a given power setting after a random excursion to any other frequency and power setting. It is a relative measurement that reflects the difference in dB between the maximum and minimum power readings for a given setting over a specific time interval. It should not be confused with absolute power accuracy, which is measured in dBm.1

Relative level accuracy

Initial power 7 dBm

	0.4
		Lower limit
	0.3	Lower STD deviation
		Mean
		Upper STD deviation
	0.2	Upper limit
	0.1
(dB)	0
error
Power	-0.1
	-0.2
	-0.3
	-0.4
	0	-20	-40	-60	-80	-100	-120	-140

Final power (dBm)

Relative level accuracy measures the accuracy of a step change from any power level to any other power level. This is useful for large changes (i.e. 5 dB steps).1

1. Repeatability and relative level accuracy are typical for all frequency ranges.

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