Phase-lock Demodulation of a PM Signal Contaminated with Incidental AM

Phase-lock Demodulation of a PM Signal Contaminated with Incidental AM
Author: George B. Robinson
Publisher:
Total Pages: 68
Release: 1972
Genre: Amplitude modulation
ISBN:

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Signals from phase-modulated satellite transmitters usually exhibit some degree of incidental amplitude modulation. The effects of incidental AM are analyzed when this type of signal is demodulated by a phase-lock receiver which does not employ a limiter preceding the loop phase detector. The presence of incidental AM causes a reduction in the receiver output signal-to-noise ratio. The tolerable level of AM decreases in proportion to the phase modulation index Beta. For a square-wave modulating signal, a 1 db reduction results at the receiver PM channel output when Beta = 1 radian and the percentage of AM = 23, Beta = 1.2 radians and the percentage of AM = 16, or Beta = 1.5 radians and the percentage of AM = 4. Although only the PM channel of the receiver is used ordinarily, utilizing both the AM and PM channel by summing offers an improvement in S/N relative to the S/N ratio of the PM channel if the percentage of incidental AM is greater than fifteen.

Amplitude Modulation of Acoustic Signals by Ocean Waves and the Effect on Signal Detection

Amplitude Modulation of Acoustic Signals by Ocean Waves and the Effect on Signal Detection
Author: James Blenn Perkins (III.)
Publisher:
Total Pages: 114
Release: 1974
Genre:
ISBN:

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A study was conducted of the amplitude modulation of an acoustic signal forward scattered from a wind-generated, model ocean surface. The demodulated spectrum of the surface scattered sound was compared with the model ocean spectrum while varying the acoustic frequency and angle of incidence. Several methods of enhancing signal detection through a knowledge of the ocean spectrum were studied. The most promising of these shows potential gains of the order of three decibels when the received signal is weak and fluctuating greatly, as at a Lloyd Mirror minimum.

The Electronics Handbook

The Electronics Handbook
Author: Jerry C. Whitaker
Publisher: CRC Press
Total Pages: 2640
Release: 2018-10-03
Genre: Technology & Engineering
ISBN: 1420036661

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During the ten years since the appearance of the groundbreaking, bestselling first edition of The Electronics Handbook, the field has grown and changed tremendously. With a focus on fundamental theory and practical applications, the first edition guided novice and veteran engineers along the cutting edge in the design, production, installation, operation, and maintenance of electronic devices and systems. Completely updated and expanded to reflect recent advances, this second edition continues the tradition. The Electronics Handbook, Second Edition provides a comprehensive reference to the key concepts, models, and equations necessary to analyze, design, and predict the behavior of complex electrical devices, circuits, instruments, and systems. With 23 sections that encompass the entire electronics field, from classical devices and circuits to emerging technologies and applications, The Electronics Handbook, Second Edition not only covers the engineering aspects, but also includes sections on reliability, safety, and engineering management. The book features an individual table of contents at the beginning of each chapter, which enables engineers from industry, government, and academia to navigate easily to the vital information they need. This is truly the most comprehensive, easy-to-use reference on electronics available.

Principles of Modems

Principles of Modems
Author: Electronic Systems Command (Navy).
Publisher:
Total Pages: 118
Release: 1968
Genre:
ISBN:

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Research of Techniques for Light Modulation Detection. Part I. Amplitude Demodulators

Research of Techniques for Light Modulation Detection. Part I. Amplitude Demodulators
Author: B. J. McMurtry
Publisher:
Total Pages: 136
Release: 1964
Genre:
ISBN:

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The results of a one-year applied research program on the demodulation of amplitude-modulated (AM) light are presented. Sufficient information is provided for the detailed understanding, design, and use of traveling-wave microwave phototubes (TWPs), the most promising detector for broadband-modulated light. The report includes: (1) the idealized analysis which first pointed out the more important TWP design considerations and operating characteristics; (2) a more complete computeraided analysis which gives detailed information on the effects of the various beam-circuit parameters and operating conditions; and (3) an analysis of the electron gun region, with emphasis on velocity spread and current density effects. The results of a detailed experimental analysis of the TWP are presented, providing both verification of the more complete theoretical treatment and information on generally-useful photodetector test techniques. Experimental data are given on several other types of photodetectors. A discussion of the design and construction of TWPs with S-1 photocathodes contains material of practical importance to TWP builders.

Electronics

Electronics
Author:
Publisher:
Total Pages: 1736
Release: 1945-07
Genre: Electronics
ISBN:

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June issues, 1941-44 and Nov. issue, 1945, include a buyers' guide section.