2-4
IM 703155-01E
Signal Flow
• Preparing Waveform Data
1.
Create waveform data on the VB8300 or on your PC.
2.
The waveform data created on your PC is retrieved into the VB8300 internal
hard disk via a communication interface, CF card, or USB memory.
3.
As necessary, convert the waveform data on the hard disk into a data format
that the VB8300 can use (RAW data, .raw extension) and load the data to the
waveform memory.
• Outputting Waveforms
The waveform memory stores waveform data of 14 bits
×
2 (I and Q), 2-bit event data
(EVENT0 and EVENT1), and 2-bit sequence trigger signal (trigger and trigger
sampling clock).
When waveform output is started, waveform data is read at the clock cycle and
passed to the 2
×
2 digital matrix calculator (matrix operation) consisting of 4
multipliers and 2 adders.
The sequence controller controls the output sequence of the waveform data and the
output count according to the settings. The matrix calculator sets the gain, phase, IQ
gain ratio, and quadrature offset. Additive White Gaussian Noise (AWGN) is added to
the data output from the matrix calculator and passed to the D/A converter (DAC) as
well as output from the IQ DIGITAL OUT terminal.
The signal that is converted into analog signal by the D/A converter passes through a
low-pass filter (select 6 MHz, 30 MHz, 100 MHz, or Through) in which unneeded
frequency components are removed. Then, a differential offset voltage is added to
the signal. Next, the signal is converted to a differential signal by the differential
output amplifier, and common-mode offset voltage is added. The signal is then output
from each output terminal (I, I
_
, Q, and Q
_
).
The 2-bit event data is read from the waveform memory and output from the EVENT
OUT 0/1 terminal.
The 2-bit sequence trigger signal is selected and synchronized by the optional
sequence trigger controller and passed to the sequence controller of each output
terminal set.* The sequence controller controls the waveform data sequence and the
output count according to the trigger signal and settings.
The analog summing output option is a function that adds the I or Q signal of each
output terminal set or an arbitrary selected signal from the external input (ANALOG
SUM EXT IN) signal and outputs the signal from each output terminal (ANALOG SUM
I, I
_
, Q, and Q
_
). Differential offset or common-mode offset voltage can further be
added to the added signal.
*
On models with single-ended outputs, four output terminal sets (OUT1 to OUT4) are
available. On models with differential output, one (OUT1) or two (OUT1 and OUT2) output
terminal sets are available.
2.2 System Configuration and Block Diagram
