Software simplifies use of AWGs for digital-RF testing
By Dan Strassberg, Contributing Technical Editor -- EDN, July 23, 2007
Tektronix has announced RFXpress, a software package for creating and editing digitally modulated RF (radio-frequency), IF (intermediate-frequency), and IQ (in-phase/quadrature) signal waveforms, which the company’s AWG5000 and AWG7000 arbitrary-waveform generators can reproduce. The software provides an intuitive user interface that, according to the company, greatly simplifies creating and managing general-purpose digital-RF waveforms. The package also accommodates specialized UWB (ultrawideband)-WiMedia plug-in software modules and a library of waveforms for thoroughly testing new digital-RF designs.
Signal generation for stress testing of new-product designs is a critical step in the development of modern wireless devices. Historically, generating such signals has been complex, often requiring many hours of tedious setup of multiple instruments. RFXpress simplifies the task by automating many repetitive and arcane functions. “Instead of creating mathematical formulas, users of the general-purpose version of RFXpress need only provide information on such parameters as frequencies and modulation schemes to predefined, fill-in-the-blanks templates,” says Mike Higashi, vice president of Tektronix’s signal-source-product line. “Moreover, the compliance and custom plug-ins add capabilities that assist in reliably and efficiently performing a wide range of tests for the UWB WiMedia standard.”
RFXpress, which supports a variety of modulation schemes, such as QPSK (quadrature phase-shift keying), QAM (quadrature-amplitude modulation), and GMSK (gaussian minimum-shift keying), also allows engineers to build their own modulation schemes. Furthermore, before you use an AWG7000 or an AWG5000 to replay RF, IF, and IQ signals captured on an oscilloscope or a Tektronix real-time spectrum analyzer, you can now use RFXpress to add impairments, interference, and distortion.
For many applications, RFXpress in combination with the AWG platform’s inherent direct-synthesis capabilities enables simpler test setups that use fewer instruments than did earlier approaches. Direct synthesis is a flexible method for creating repeatable ideal and impaired waveforms that an AWG (arbitrary-waveform generator) can then directly synthesize. For example, the RFXpress WiMedia custom-mode plug-in enables engineers to individually configure every part of the WiMedia frame and packet to thoroughly characterize, limit-, and stress-test the receiver's PHY (physical) layer.
RFXpress runs as an integral part of the AWG5000 or AWG7000 or as a stand-alone application on an external PC. The US suggested price for general-purpose RFXpress is $5000. The UWB WiMedia compliance plug-in costs $2200, and the UWB WiMedia custom plug-in costs $7200.
