1. High-T/sub c/ superconducting small antennas
- Author
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O. Ishii, K. Itoh, O. Michikami, Yasuhiro Nagai, Y. Kimachi, and N. Suzuki
- Subjects
Physics ,Coaxial antenna ,business.industry ,Loop antenna ,Antenna measurement ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Radiation pattern ,law.invention ,Antenna array ,Optics ,Nuclear magnetic resonance ,law ,Dipole antenna ,Electrical and Electronic Engineering ,Antenna (radio) ,business ,Monopole antenna ,Computer Science::Information Theory - Abstract
The authors describe the designs of and report experimental results for one- and two-element high-T/sub c/ superconducting small antennas composed of self-resonant helical radiators and quarter-wave matching circuits. A 500-MHz-band antenna using a lambda /40 ( lambda is the free-space wavelength) radiator fabricated with Bi(Pb)SrCaCuO bulk realized a gain of -1.2 dBi, which indicates that this antenna achieves a high frequency of 70%. A 900-MHz-band two-element array antenna using lambda /20 radiator with a lambda /11 element spacing was designed to obtain a superdirective radiation pattern. The array antenna thus fabricated with YBaCuO bulk realized both a higher efficiency than a Cu antenna and a unidirectional radiation pattern. Furthermore, by adopting EuBaCuO thin-film meander lines as the matching circuit, the total length could be reduced to about 1/4 that of an antenna using a linear circuit. >
- Published
- 1993
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