Agilent Technologies e4419b, e4418b manual Adjustment Setup, Equation

Adjustments

Power Reference Oscillator Level Adjustment

Note	The power meter may be returned to the nearest Agilent Technologies
	office to have the power reference oscillator checked and/or adjusted.

Power Meter Power

ref

Agilent 432A

Power Meter Digital

Voltmeter

VRF	+ INPUT
Vcomp	INPUT

Thermistor

Mount

Figure 3-3: Adjustment Setup

For this adjustment the following mathematical assumptions are made:

Equation 1:

2Vcomp(V1 – V0) + V02 – V12

P = ----------------------------------------------------------------------------------

meas 4R(CalibrationFactor)

can be manipulated to give the following:

Equation 2:

V1 = Vcomp + V0 – Vcomp2 – (10)–3(4R)(CalibrationFactor)

by using the following assumptions:

V02 – V12 = –(V1– V0)2

The error in doing this is:

–(V12 + V02 – 2V1V0) – (V02 – V12) = – 2V02 + 2V1V0 = 2V0(V1 – V0)

So if 2V0(V1 – V0) « 2Vcomp( V1 – V0) , that is, V0 « Vcomp then the error can be ignored. In practice Vcomp ~ 4Volts and V0 < 400∝V . The error is less than 0.01%.

Agilent E4418B/E4419B Service Guide 3-7