SPHERICAL ANTENNAS HAVING ISOTROPIC RADIATION PATTERNS

摘要

ABSTRACT OF THE DISCLOSURESpherical antenna arrangements are disclosed utilizing annularslots in polar regions which are associated with resonant cavities havinga TE01 mode or a TE11 mode of field distribution. This field distributionwithin the cavity produces a cosine field distribution around the annularslot which serves via proper cavity excitation to produce nearly hermis-pherical isotropic radiation characteristics. The resonant cavities maytake on the form of a parallel-plate structure or a coaxial cylindricalstructure. Circular polarization and hemispherical coverage with uniformgain is characteristic of the antenna when the cavities contain probesplaced ninety degrees apart in azimuth at the same radius from center andcoupled to the quadrature phase related ports of a signal coupler.