VXI 3002 - Manual (Page 74)

4-1
Chapter 4
TECHNICAL DESCRIPTION
Introduction
The 3002 VXI Signal Generator is a VXI module which covers a wide range of frequencies from
9 kHz to 2.4 GHz. Output levels from -137 dBm to +25 dBm are available. These are C size, 2-
slot wide plug-in modules that require a VXI bus mainframe for operation.
The simplified block schematic diagram for the instrument is shown in Fig. 4-1.
Modulation
The carrier frequency can be frequency, phase or amplitude modulated from internal or external
sources. The internal source can be the sum of two signals and used in combination with an
external source connected to the front panel EXT MOD INPUT connector.
Frequency generation
A voltage controlled oscillator (VCO) covering the frequency range 400 to 533 MHz is phase
locked to a 10 MHz temperature controlled crystal oscillator using a fractional-N synthesizer
system. Additional frequency coverage is achieved by means of frequency division and
multiplication. Low frequencies are generated by a beat frequency oscillator (BFO) system.
Control
Internal control of the instrument is achieved by a microprocessor which receives data and sends
instructions via an internal 8-bit data bus to the signal processing circuits.