Abstract
A monofilar Archimedean spiral is adopted as a circularly polarized slot radiator which is electromagnetically coupled to a feed line. Numerical analysis of the coupling between the slot and the feed line reveals that, when the slot arm length is properly chosen, a traveling-wave magnetic current is distributed along the slot, leading to the radiation of a circularly polarized wave. On the basis of this radiation mechanism, a spiral slot printed antenna fed by a triplate transmission line is experimentally designed to obtain a unidirectional radiation beam. It is found that an axial ratio of 0.6 dB is achieved, and that the spiral slot is matched to the transmission line with a VSWR of less than 1.5. An array antenna composed of 32 printed spiral slots is constructed, attaining a 5% bandwidth for a 3-dB axial ratio criterion. The formation of several tilted beams is also demonstrated.
| Original language | English |
|---|---|
| Pages (from-to) | 415-426 |
| Number of pages | 12 |
| Journal | Electromagnetics |
| Volume | 14 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 1994 Jan 1 |
| Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Radiation
- Electrical and Electronic Engineering