Abstract
A novel single-feed tri-band circularly polarized (CP) dual-annular slot antenna is presented. The antenna structure is composed of two nonconcentric annular slots fed by a novel inverted h-shaped microstrip line configuration. Compared to most of the previously reported tri-band CP antenna structures, the proposed antenna has low profile, compact in size, and easy to fabricate on the single-layer PCB. It is easy for the antenna to match all the three frequency bands by employing an h-shaped feeding line. The antenna also can provide a conical radiation pattern at the third band. A sample design of a tri-band CP antenna operated at 1.58, 2.42, and 3.0 GHz is realized. Details of the experimental results compared with simulated results are presented and discussed. The proposed compact tri-band CP antenna design is suitable for mounting onto the mobile communication devices and portable positioning systems.
Acknowledgment
This work is supported by Singapore Ministry of Education Academic Research Fund Tier 1 Project R-263-000-667-112.