Application of Inductive Loadings for the Dual and Broad Banding of CPW-Fed Ring Antennas

The broad banding of a printed ring antenna is achieved through inductive loadings by open-circuited radial line sections distributed around its periphery. The bandwidth of the stub loaded ring antenna is significantly enhanced without minor degradation of its radiation patterns, which may be realized by the appropriate design of widths, lengths, and angular spacings of open circuited radial lines. Dual-band performance can also be obtained by the application of the proposed method. The proposed antenna configuration is verified by computer simulation together with fabrication and measurement.