Agilent Technologies 8922 Block Diagram 3 HP/Agilent 8922B Only

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Block Diagram Theory of Operation

Block Diagram 3HP/Agilent 8922B Only

The HP/Agilent 8922B contains 3 modules: A35 “B” Reference; A36 FIFO/GPIO; and

A37 Sequence Controller assemblies that are not used in either the HP/Agilent 8922A or

HP/Agilent 8922G. The function of these three modules can only be controlled using the

rear panel GPIO connector (found only on the HP/Agilent 8922B) and the special control

softwarethat is supplied with the HP/Agilent 8922B. At power-up, the HP/Agilent 8922B

appears to be an “A” version and should respond exactly the same as an HP/Agilent

8922A. The overall operation of the HP/Agilent 8922B is to buffer and synchronize data

from an external computer. This data is then transmitted by the HP/Agilent 8922

Generator hardware. The internal connections of this hardware are illustrated in Block

Diagram 3.

Tothe user at the front panel and for the memory card diagnostics, the instrument appears

to be an HP/Agilent 8922A. Any signals that are generated by the HP/Agilent 8922B

hardware appear as “external” for the control settings.

Fordiagnosing problems with these modules, it is necessary to use the HP/Agilent 8922B

software. The software contains testing routines that load the buffers with data and read

thedata back. The software is also necessary to control the switches and circuits within the

modules.

This module contains the VCO and divider circuits necessary to lock to most common

referencefrequencies used for GSM radio testing. These include 1, 2, 5, 10, and 13 MHz,

as well as 270.833 kHz data rate clock and 216.667 kHz frame rate clock. The frequency

must be selected using the software provided with the HP/Agilent 8922B.

This module provides a 10 MHz signal to the rear panel and a 270.833 kHz signal to the

A37 Sequence Controller assembly.

The A36 FIFO/GPIO assembly has 2 primary functions. The ﬁrst is to communicate

throughthe GPIO bus to an external controller and relay these control signals to the other

HP/Agilent 8922B modules. To control any of the HP/Agilent 8922B modules it is

necessarythat the A36 FIFO/GPIO assembly communications are working correctly. The

second function of the A36 FIFO/GPIO assembly is to store and send the digital data

informationthat is “transmitted” by the RF Generator portion of the HP/Agilent 8922. The

diagnosticsoftware has a FIFO RAM test to verify that the hardware can send and receive

data from the external computer.