MICROWAVE NANOSECOND PULSE-GENERATOR STUDY.
Abstract
The possibility of generating very short pulses of microwave energy at very high power levels by the use of a spark gap was studied. In Task I of the program the use of solid dielectric, in the form of a disposable tape, was studied as a means of increasing the voltage hold-off of a given gap and so increasing the output power. It was shown that this is indeed an effective means of boosting the operating power. In Task II the possibility of using a fast-rise driving pulse to obtain over-voltaging and increased power was investigated. The results indicate that there is little to be gained over the use of an ordinary modulator (with, say, 100 ns rise time), at least until the rise time is shortened to the statistical time for initiation of the discharge -- about 15 ns in air at normal pressure. Under Task III computations were made which showed the extreme sensitivity of this type of device to transient resistance during establishment of the discharge. It was shown that to obtain any reasonable efficiency, the duration of the transient resistance must be held to 1/4 to 1/2 of the RF period. Task IV concerned the design of the generator itself and the determination of its significant properties. A general classification of spark-gap generators is given, and the distinctive characteristics of each type discussed. Under Task V, methods were developed for precise analysis of the frequency modulation that may be present in pulses of the sort generated by the devices. In general, it was found that the pulses from the generators exhibit little frequency modulation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1967
- Accession Number
- AD0821583
Entities
People
- Arthur Karp
- Marshall C. Pease
Organizations
- SRI International