Signal processing using surface acoustic waves

Signal rug Using Surface Acoustic Waves, by William R. Shreve Compact, rug ged SAW correlation, that require no adjustment make real-time convolution, correlation, and dispersive filtering less difficult. Retrofitting for Signature Analysis Simplified, by Robert Rhodes-Burke Signature analysis is a great help in troubleshooting digital products designed to use it, but what about all the products that aren't? A Fast, by High-Quality Digital Display for Instrumentation Applications, by Kunio Hasebe, William R. Mason, and Thomas J. Zamborelli Why design a custom display when you can just plug one in? This one is easy for a microprocessor to talk to. Electronic instruments and systems usually have a display of some kind to present data to humans have a readily understandable form. More and more, such systems have microcomput ers inside, and while they may be fed continuously varying real-world quantities like voltages, speeds, and temperatures, the first thing they do with this analog data is convert it to binary numbers so that internally they can operate entirely digitally. This month's cover subject, the 1 345A Graphics Display Module, is a high-quality cathode ray tube display that's designed to be built based spectrum analyzers, network analyzers, and other electronic instruments based on microcomputers. The 1 345A is easy for a microcomputer to talk to, because it understands picture descriptions in a simple binary language. With it, an instrument designer can provide high-quality graphics and text while avoiding the time and expense required to design a custom display. Among the 1345A's contributions are its speed, line quality, resolution, number of brightness levels, and compactness †" the entire module page 20. a little larger than the CRT. It tests itself, too. The design story begins on page 20. Complex digital systems, especially computers and microcomputer-based products, are particularly difficult to troubleshoot. If you connect an oscilloscope to any point in a digital circuit, you see a voltage switching rapidly between system, levels. Without specialized test equipment and detailed knowledge of the system, it isn't possible to tell whether that "bit stream," as it's called, is correct. Yet it's impractical for every field service technician to have that developed Guided knowledge and equipment. Signature analysis was developed as a response to this problem. Guided by a test numbers the technician probes points in the system and observes four letters and/or numbers (a signature) displayed by a compact instrument (a signature analyzer). Comparing these signatures …