Design of a highly miniaturized compound spiral antenna

The design simulation and measurement of a highly miniaturized compound spiral antenna is presented. The compound spiral antenna is designed by combining a typical equiangular spiral antenna with new terminals. Favorable wideband properties are shown in the simulated and measured results. The measured return loss is less than -10 dB in the frequency range from 1.6 to 10 GHz and the axial ratio is much less than 3 dB between 1.2 GHz and 10 GHz, and significantly the proposed antenna has a 44.8% reduction at lower operating frequency by comparison with the typical equiangular spiral antenna with the same size.