User’s and Service Guide U3047-90001
57
U3047AM12
Service Information
Theory of Operation
The following is a description of the operation of the test set. Reference the test set block diagrams shown
in
. This section assumes the user has a general understanding of couplers, switches,
and network analyzers.
The test set adds 12 test ports to a 4-Port network analyzer. The internal RF switches direct the source and
receiver signals of the network analyzer to the selected measurement test port.
The switches and couplers are arranged in four groups to control the source and receiver paths of the
network analyzer port to the couplers in the column under the network analyzer port.
Test Set Control Board
The Test Set Control Board (N5261-60006) is a surface mount, printed circuit assembly (PCA). It provides a
connection to the power supply, and the network analyzer Test Set I/O for control of the RF switch paths
(through the Switch Interface board (U3025-60068). The front panel “Active” and port LEDs are on only
when the network analyzer has addressed the U3047AM12 test set. The rear panel fan is on when the
controller board supplies are operational.
Switch Interface Board
The Switch Interface board (U3025-60068) is installed on top of the test set Controller Board and provides
connections to the RF switches. This board regulates the DC voltage supply (24 volts), and routes logic
signals to the switches through harness cables connected to plugs J10-17, J20-27, J30-37 and J40-47.
Front Panel LED Boards
Four LED board assemblies (N5261-60005) are mounted to the front panel. The LED’s indicate the Source
Path (amber/yellow color), or Receiver Path (green colored) shown as “S” and “R” on the front panel. The
LED board assemblies are connected to the test set controller board by ribbon cables to J5, J6, J7 and J8.
DUT Control Board
The DUT Control Board (E5091-66503) provides eight control lines for controlling an external device. The
DUT Control Board installed on the rear panel and is connected to the test set Control Board through a
ribbon cable to J9.
Power Supply
The switching power supply (0950-4729) coverts the AC line voltages to DC. This is an automatic line
voltage selecting power supply. The DC supplies are connected to the test set control board through four
wire harness to J11, J12, J13 and J14. The 9/10 Vdc section of the power supply is not used in this
instrument. The AC line voltage (100 to 240 V @ 50/60 Hz) is provided from the line module on the rear
panel.
RF Coupler
The test set uses 12 couplers (5087-7754) on the front panel for RF Test Ports 5-16. The couplers provide
the signal separation of the source and receiver paths. The test set ports can receive from or stimulate a
signal to the DUT.
The RF Test Port connectors are male 1.85 mm. The coupling factor is approximately -18 dB for the Coupled
Arm for frequencies > 1 GHz to 67 GHz (approximately
−
53 dB < 1 GHz). The insertion loss through the
CPLR THRU path is typically < 4 dB at 67 GHz.
Summary of Contents for U3047AM12
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