RESEARCH ON THE THEORY AND DESIGN OF ACTIVE NETWORKS.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1964
- Accession Number
- AD0609434
Entities
People
- Kjell Blotekjaer
- Tor Schaug-pettersen
Organizations
- Norwegian Defence Research Establishment