A6 Test Head Board(For The Standard And Option 010); A10 Analog Motherboard; A2 Dc Bias Board (Option 001); A5 Reference Oven Board (Option 1D5) - Agilent Technologies E4991A Service Manual

Table 5-4 Input Attenuator
Nominal Setting of
Output Power Level
12.9 dBm ~ +1 dBm
22.9 dBm ~ 13 dBm
40 dBm ~ 23 dBm
The variable gain IF amplifiers automatically control the IF signal levels to be within
appropriate range for the input of the ADC (analog to digital converter).
The digitized data at ADC is transferred through A10 analog motherboard to the DSP on
A21 analog interface board which performs vector component extraction and calculation
for the Vch and Ich signal data.

A6 Test Head Board(for the standard and Option 010)

A6 test head receives the stimulus signal from the A3 source board through RFOUT port
and test cable(Opt.010), and applies it to the DUT (device under test). At the same time, the
test head outputs two signals(Vch and Ich signals) that represent the voltage across the
DUT and the current through the DUT.

A10 Analog Motherboard

A10 analog motherboard connects A1, A2, A3, and A4 to A21 analog interface board.

A2 DC Bias Board (Option 001)

A2 DC bias board contains a DC bias source that provides a bias voltage up to 40V and a
bias current up to 100 mA.
The bias voltage across the DUT and the bias current through the DUT are monitored and
feedback to the bias source. This feedback operation automatically maintains the bias
voltage or current at the same level as the setting value regardless of the DUT's dc
resistance. The bias source allows a current compliance(limit) to be applied in the voltage
bias mode and a voltage compliance in the current bias mode.

A5 Reference Oven Board (Option 1D5)

A5 reference oven board supplies a high stability 10MHz external reference signal to A1
reference oscillator board via an external connection path between rear panel BNC
connectors. When the 10MHz external reference output (Option 1D5) is connected to the
EXT REF Input connector on the rear panel, the internal REF OSC output signal is phase
locked to the external reference signal.
Chapter 5
Input Attenuator on
A4
20 dB
10 dB
0 dB
Theory of Operation
Analog Section
229