APPLICATION OF THE SLOT ANTENNA TO POWER DENSITY MEASUREMENT
Abstract
The narrow-band properties of the normally-resonant slot antenna are altered significantly as the load resistance is reduced. For example, an antenna with a length-to-width ratio of 30, has its 1 db max-min wavelength ratio changed from 3 to 11 as the resistance is reduced from 50 to 10 ohms. This bandwidth increase is accompanied by a reduction in aperture and hence sensitivity. Because of this, as well as other practical considerations, it does not appear that the required 100:1 wavelength ratio can be obtained by this means alone. Changing the dimensions of the slot also affects the bandwidth as might be expected from the analogous behavior of fat vs thin dipoles. For a fixed loading of 10 ohms, the length-to-wavelength ratio for a 1 db decrease in sensitivity changes from 0.063 to 0.02 for a corresponding change in length-to-width ratio from 15 to 2. Increasing reactance at the low end of the band and a sharp increase in effective length near the high end of the band can separately be compensated, at least theoretically, by the introduction of capacitance both in series with and in shunt with the load. With this additional compensation a loaded slot antenna can be made which theoretically will cover the required 100:1 frequency band. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1961
- Accession Number
- AD0276522
Entities
People
- Kamal Ya'coub
Organizations
- University of Pennsylvania