| 摘要 |
The aerial is surrounded by a lose-free dialectric material with a large thickness where the field strength is the greatest. The field strength and thus the heating in the limit layer between loss-free and loss-impaired dielectric material remain the same over the whole aerial. A bi-conical aerial is used which is surrounded by a dielectric material with low losses and with the greatest thickness where the electrical field strength is high. Alternative versions involve the aerial being a metal cone fixed in a tube of dielectric material with low loss, and with the greatest thickness where the electrical field strength is high. The aerial may also be cylindrical and encased by dielectric material, also with the greatest thickness where the electrical field strength is high. The aerial encloses a radio-active preparation. |
