General limits on the performance of high power radiators

摘要

Performance of high power radiators of electromagnetic energy can be limited by constraints such as those due to voltage holding, corona power loss, and antenna impedance and efficiency. The issues are addressed in such a way that general limits on the electric field and energy at a distance is obtained as a function of wavelength, pulse duration, and size of the radiating element. We address the relation between the frequency content of the driving pulse and the complex impedance of the antenna; the importance of minimizing the antenna impedance and therefore limiting the antenna input voltage is clearly shown. For example, driving the antenna at a resonance with a simple oscillating waveform is shown to allow the radiation of energy with two to three times the efficiency of a mono-polar pulse input. With this information, the prospects for a successful system design of a given size to deliver a specified amount of radiation to a target at a given distance can be quickly assessed.