关键词: 径向线螺旋天线, 圆极化, 主螺旋线, 副螺旋线, 低剖面

Abstract: In satellite communication, circularly polarized (CP) antenna is an important component, which is responsible for the signal reception and transmission. Curl antenna is an important CP antenna. Traditionally, the height of the curl antenna needs to achieve 0.15 λ0. This paper proposes a novel design which composed of a major curl and an assistant curl. Due to the introduction of the coupling between the assistant and major curls, the height of the antenna can be decreased greatly. Simultaneously, using the chip capacitor along the feeding structure, the matching of the antenna can be improved and adjusted conveniently. The height of the proposed low-profile curl antenna is about 0.0525 λ0, which is only about 34% of the traditional single-curl antenna. In order to verify the theoretical prediction, a prototype on FR4 substrate is designed at 1.54 GHz. Measured results show that the 10-dB matching bandwidth and 3-dB axial ratio bandwidth is 900 MHz and 27 MHz, respectively, and the gain is 2.9 dBic.

Key words: curl antenna, circularly polarized, major curl, assistant curl, low-profile