Square-shaped feeding truncated circularly polarised slot antenna

Abstract

A novel S-band right handed circularly polarised (RHCP) slot antenna for supporting communication system of GAIA II/LAPAN-Chibasat is presented in this paper. This satellite implemented L-band Circularly Polarised Synthetic Aperture Radar (CP-SAR) sensor, X-band antenna is employed for mission data downlink and S-band antenna is employed for the command and telemetry. The S-band antenna is printed on the substrate with the relative permittivity of 2.17 and the thickness is 1.6 mm. A crescent shaped slot is placed on the ground plane. A square-shaped is set to strengthen the radiation on the edge of the feed-line. A parasitic strip rectangular-shaped is added on the ground plane to enhance the gain of the antenna. Truncation technique is employed to increase the bandwidth axial ratio(ARBW) and the gain. The total dimension of the antenna is 170 mm × 170 mm. The antenna produced < 3 dB bandwidth axial ratio of 14% and the bandwidth under -10 dB of return loss obtained 90%.The simulated and measured result of the antenna design is satisfied. Detail of the antenna design and the measurement result of the antenna are described and presented.