APPLICATION OF PRE-DETECTION AND RECORDING TECHNIQUES TO DATA COLLECTION SYSTEMS.
Abstract
The report evaluates pre-detection recording techniques for uncooperative signal acquisition with particular emphasis on the problems associated with wide band, wide dynamic range AM signals. Since the pre-detection recording process is placed in series, between the IF amplifier and the data processing circuits, new sources of noise and distortion are introduced. One of the basic problems is to identify the sources of signal degradation in the pre-detection process. The influence of receiver characteristics on the pre-detection recording process is discussed in Section 3. In Section 4, several techniques for down-conversion of IF signals to a center frequency compatible with a wideband tape recorder are discussed. Section 5 discusses tape recording techniques and Section 6 reviews the relative merits of several up-conversion schemes. The specific problems associated with pre-detection recording of AM signals are discussed in Section 7. Appendix A develops a scheme for a broadband 90-degree phase shifter which is of considerable value to the up-conversion problem, and gives the test results of a breadboard of the phase shifter. Appendix B gives the test results on a commercially available down-converter. Appendix C, written by L. N. Ferguson, discusses the 'care and feeding' of wide band tape recorders.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1965
- Accession Number
- AD0629889
Entities
People
- Ray D. Lucas
Organizations
- Sylvania Electric Products