Dual-spiral slot array antenna fed by triplate transmission line

The fundamental radiation characteristics of a dual-spiral slot (DSS) fed by a triplate transmission line (microstrip) are presented. The triplate transmission line reduces the antenna thickness. The DSS radiates a circularly polarized wave over a wide range coverage around the Z-axis. An array using 32 DSSs attains a 5% bandwidth for a -14 dB return loss criterion. A DSS array antenna was constructed and tested in the 12 GHz band.<
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