Circularly polarized high-gain printed antennas for small satellite applications

Two new circularly polarized printed antennas are designed and simulated. The characteristics of the antennas are obtained in terms of return loss, gain, bandwidth and axial ratio. Some simulated results are discussed. To broaden the impedance bandwidth, an air gap configuration is utilized. To broaden the axial ratio bandwidth, a dual feed is adopted. To increase the gain of the circularly polarized antenna, a parasitic patch above the driven patch is used as a director. To reduce the dimensions and broaden the 3-dB axial ratio beamwidth, a rim is introduced. Detailed parameters and simulated results of the proposed antennas are given. The circularly polarized high-gain antennas can be used in satellite data down links thanks to its advantages of low cost and easy fabrication. Simulation of the proposed antenna mounted on a typical micro satellite at Surrey has been done and some results are given which demonstrates the reliable performance.