Accession Number : AD0478459

Title :   ELECTRON TUBE RESEARCH.

Descriptive Note : Quarterly progress rept. no. 12, 1 Sep-30 Nov 65,

Corporate Author : ELECTRICAL ENGINEERING RESEARCH LAB CORNELL UNIV ITHACA N Y

Personal Author(s) : DeClaris,N.

Report Date : 30 NOV 1965

Pagination or Media Count : 86

Abstract : A pulse-modulated oscillator was built to simulate the effects of fading on a Barker code over the entire range of fading rates of interest. The measured bandwidth of the time-variable attenuator is compared. The results of measurements of the composite system to determine its linearity are given. The degradation caused by a time-varying channel in the performance of a coded-pulse radar is studied. An expression is found for the degradation, averaged over an ensemble of coded-pulse radar systems, of a channel modeled as a zero-mean, homogeneous, random, time-variant linear filter. Pseudo-periodic codes of short period are examined. A criterion for selecting best binary codes is described. The differential equation representing the optimum class of signals for high resolution radars is solved for a different class of endpoint conditions. The subclass of two input signals is solved and proved to be optimum. The purpose of this study is to obtain improved algorithms for numerical evaluation of uncertainty and ambiguity functions of discrete, amplitude-phase modulated signals. In this report the problem is formulated and an algorithm for the Fourier cosine transform, which results from linear approximation of the phase modulation, is derived. A cathode-coupled monostable multivibrator is designed to give an output of square pulses with a duration of nanoseconds. Metal-ceramic 7077 triodes are used as the switching elements. (Author)

Descriptors :   (*PULSE GENERATORS, *RELAXATION OSCILLATORS), (*PULSE AMPLIFIERS, *ATTENUATORS), ATTENUATION, RADAR SIGNALS, PHASE MODULATION, AMPLITUDE MODULATION, TRIODES, BANDWIDTH, HIGH FREQUENCY, VERY HIGH FREQUENCY, RADAR TRANSMITTERS, RADAR RECEIVERS

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE