SDR architecture quickly adapts RF-vector-signal generator to changing test needs
By Dan Strassberg, Contributing Technical Editor -- EDN, February 16, 2006
When testing devices that conform to multiple wireless standards, fast switching among waveforms is critical for keeping test times within reason. Keithley Instruments' Model 2910 400-MHz to 2.5-GHz RF vector-signal generator incorporates several innovations to reduce test times. Unlike those of competitive instruments, the instrument's outputs settle within 1.5 msec. Moreover, a sync-out, source-settled indicator illuminates only when the source has settled. These features eliminate the need to add wait states to test programs to ensure that the generator's output has settled before the device under test uses the signal. In addition, the instrument's 16-bit-resolution, two-channel, 64M-sample arbitrary-waveform generator supports simultaneous loading of multiple signal waveforms and enables switching among these signals in less than 5 msec.
The unit's SDR (software-defined-radio) architecture adapts as wireless standards evolve. For mobile-phone testing, the unit offers optional built-in signal-generation software personalities for key cellular formats. You can easily upgrade the unit to new and emerging standards as they become available. For signal formats that the initial release does not include, the unit's arbitrary-waveform generator supports downloading of virtually any externally generated signal waveforms with bandwidth as great as 40 MHz. In addition, the instrument can generate RF signals with bandwidth as great as 200 MHz from user-provided analog-baseband in-phase and quadrature signals.
The bandwidth and architecture of the Model 2910 provide a significant future cost savings, because customers need not purchase new RF sources as new wireless applications emerge. The price of the 7-in.-high, half-rack-wide instrument is $14,500. For easy integration into test systems, the generator, which incorporates IEEE 488, USB, and 100 BaseT Ethernet interfaces, conforms to LXI (LAN extensions for instrumentation) Class C. To assist users in quickly developing applications, the instrument includes comprehensive help documentation that is accessible from the front panel, the remote interface, or a CD-ROM.
Keithley Instruments, www.keithley.com.
