A16 Test Set Motherboard - Agilent Technologies PNA Series Service Manual

Theory of Operation
Source Group Operation
• In the third path, a portion of the second-path signal is doubled to produce the 40.0 to
44.7 GHz output for band 21.
The source ALC circuitry (located on the A16 test set motherboard) provides feedback to
the SOMA 50 to control the output power level.

A16 Test Set Motherboard

The A16 test set motherboard serves these functions:
• to act as an interface between the A15 CPU board and the auxiliary rear panel
interconnects.
• to provide ALC signals to the A21 SOMA 50 and to the A18 multiplier/amplifier.
• to route control signals to the signal separation group. Refer to
Group Operation" on page 5-16
Rear Panel Interconnects
The A16 test set motherboard includes the following rear panel interconnects.
TEST SET I/O
HANDLER I/O
AUX I/O
I/O 1 (TRIG IN)
I/O 2 (TRIG OUT)
5-12
for more information.
A DB-25 female connector that is used to control external test sets. The
external test set bus consists of 13 multiplexed address and data lines, three
control lines, and an open-collector interrupt line. Pin assignments are
listed in Table 5-3 on page
Up to 16 test sets may be "daisy-chained" on the bus at one time.
The Test Set I/O is not compatible with 8753 network analyzer test sets.
A rectangular 36-pin, female connector providing four independent parallel
input/output ports, nine control signal lines, one ground, and a power
supply line. This connector has Type 2 output pin assignments as listed in
Table 5-4 on page 5-14.
All signals are TTL-compatible. Data input/output ports consist of two 8-bit
output ports (Port A and Port B) and two 4-bit bidirectional ports (Port C
and Port D).
Connector settings can be changed using SCPI and COM commands. The
settings are not accessible from the front panel.
A DB-25 male connector that provides a variety of both analog and digital
input and output signals as described in
A BNC connector for input of an external trigger. The analyzer can be
triggered by an external device using this input. This is the same signal
that appears on AUX I/O pin 19 as described in
A BNC connector for output of a trigger signal. This trigger signal can be
used to trigger external devices used in the measurement setup, such as
signal generators.
PNA Series Microwave Network Analyzers
"Signal Separation
5-13.
Table 5-5 on page
Table 5-5 on page
Service Guide E8361-90001
E8361A
5-15.
5-15.