The N8241A is another AWG with
15-bit resolution. Its sampling rates and
bandwidth options are the same as the
N8242A. All of these units use the LXI
interconnect system and are typically
mounted in a compact enclosure like
the N8200 (Fig. 3, again). For software,
Agilent offers the Vector Signal Analysis
package and Signal Studio suite.
Of course, National Instruments is a
natural to offer synthetic instrumentation,
since its basic products are close to the
standard definition of SI. NI’s PXIe-1075
chassis, which consists of modules for
each of the major blocks in an SI system tem, has 18 slots for both PXI and PXIe
modules. Figure 4 shows the PXIe-5663
6.6-GHz vector signal analyzer (VSA) and
the PXIe-5673 6.6-GHz vector signal
generator (VSG).
The 5663 VSA is an instrument unto
itself, consisting of three NI PXIe modules—
the 5601 RF downconverter; the
PXI-5652 CW voltage-controlled oscillator
(VCO), which is used as a local oscillator;
and the PXIe-5622 digitizer, a 16-bit
150-Msample/s ADC. These modules can
be used individually for SI configurations.
The PXIe-5673 VSG is also an instrument,
but it comprises three separate modules—
the PXIe-5450 dual-channel AWG
with DAC outputs, the PXI-5652 CW
local oscillator, and the PXIe-5611 RF
upconverter. Again, the individual modules
may be configured into the desired SI
format. These modules can be connected
to form a basic SI (Fig. 5). The local oscillators
aren’t shown.
NI’s RF test systems are designed to
work with the company’s well-known
LabVIEW software. Using this softwaredefined
architecture provides great measurement
flexibility. Users can develop
their own wireless protocols or utilize standard
specific LabVIEW toolkits that generate
and measure most wireless standard
signals. The latest version of LabVIEW
8.6 implements parallel measurement
algorithms on multicore CPUs. This
can mean significantly faster measurements
than those made on more traditional
instruments.
Phase Matrix makes a line of VXI bus
and PXI bus modules suitable for use in SI
systems. These include signal generators,
downconverters, and local oscillators. The
company’s newest products targeting SI
revolve around a family of RF/microwave
downconverter modules for the PXIe bus.
These modules can be configured into any
one of six primary modes operating over
the frequency ranges of 100 kHz to 2.9
GHz, 2.7 to 26.5 GHz, and 100 kHz to
26.4 GHz.
The modules include the RF input conditioner
module, the microwave band input
module, the low band input module, the
local-oscillator module, and the IF output
conditioner module. They’re designed to
support small, portable, and transportable
synthetic instruments that can be programmed
to perform signal analysis or to
emulate older, obsolete instruments.
Also, the modules use programmable
input signal conditioning in the form
of pre-selection filtering in the 2.7- to
26.5-GHz range with bandwidths of
40 MHz minimum to 120 MHz maximum.
The input attenuator can be programmed
from 0 to 70 dB in 10-dB steps.
Local-oscillator switching speed is less
than 1 ms.
These downconverters operate in both
a narrow-band IF of 21.4 MHz and a
wide-band IF of 250 MHz. The units
are designed to work with National
Instruments’ digitizers and other
PXIe modules.
Phase Matrix has joined with BAE Systems
and National Instruments to produce
a next-generation 26.5-GHz synthetic
instrument based on the PXI platform for
military and aerospace applications. BAE
Systems is a defense and aerospace company
offering products and services for air,
land, and naval forces.
REFERENCES
Lupinetti, Francesco, “New Synthetic
Instrumentation Methods Solve Tough
System-Level Test Problems,” Electronic
Design, January 31, 2008.
Nadovich, C.T., Synthetic Instruments:
Concepts and Applications, Newnes/Elsevier,
2005.