Successful specification development for radio test systems

The simple walkie-talkie radio is no longer quite so simple. Voice communication now utilizes advanced digital modulation techniques, and that old reliable handheld radio may now include data communications capabilities that allow the user to receive real-time battlefield data updates or even browse the Internet. Radios have become complicated. As radio designs have become more complicated, testing those radios has become accordingly more difficult. Test stations must now be able to demodulate digital waveforms and deal with complex data. An RF test system can no longer be designed by a person, no matter how experienced, who has only a general knowledge of radio operations. The details are important. Likewise, when writing specifications in advance of test system procurement, it's critical to understand exactly what needs to be tested. This paper focuses on methods that can be used to determine RF test system specifications in advance of procurement. For any complex design problem there exists a set of best practices that usually leads to success, and there exists a set of common design practices that frequently leads to failure. Based upon Agilent Technologies' decades of experience, this paper discusses some of each. Examples gleaned from recent test system specifications will be used as highlights, but the techniques described in this paper will be useful to anyone who is tasked with writing specifications of any kind.