Accession Number : AD0609434

Title :   RESEARCH ON THE THEORY AND DESIGN OF ACTIVE NETWORKS.

Descriptive Note : Annual summary rept. no. 3, 1 Jul 63-30 Jun 64,

Corporate Author : NORWEGIAN DEFENCE RESEARCH ESTABLISHMENT KJELLER

Personal Author(s) : Blotekjaer,Kjell ; Schaug-Pettersen,Tor

Report Date : 23 JUL 1964

Pagination or Media Count : 36

Abstract : The report is concerned with studies in microwave ultrasonics and acoustic wave propagation in piezoelectric semiconductors. Saturation due to acoustic oscillations in cadmium sulphide have been observed experimentally, and the drift mobility of electrons in the sample has been determined to 210 square cm/Vs at room temperature. A nonlinear coupling between acoustic waves and electromagnetic waves in piezoelectric materials is described, and an experiment for parametric excitation of subharmonics is outlined. The thermal noise due to free carriers in electroacoustic amplifiers is calculated. The equivalent noise temperature can be made considerably lower than the temperature of the amplifying crystal. A novel design of an efficient piezoelectric transducer for hypersonic waves is described. The coupler comprises a number of piezoelectric discs in a specific arrangement located in the gap of a reentrant microwave cavity. (Author)

Descriptors :   (*SOLID STATE PHYSICS, ACOUSTICS), (*MICROWAVES, ULTRASONIC RADIATION), (*ACOUSTICS, PIEZOELECTRIC CRYSTALS), (*ULTRASONIC RADIATION, PIEZOELECTRIC CRYSTALS), NETWORKS, CADMIUM COMPOUNDS, SULFIDES, HARMONIC ANALYSIS, NOISE, PROPAGATION, SEMICONDUCTORS, ELECTROMAGNETIC RADIATION, AMPLIFIERS, TRANSDUCERS, ELECTRONS, PHONONS, TRAVELING WAVE TUBES, OSCILLATION

Distribution Statement : APPROVED FOR PUBLIC RELEASE