Dual-band dual-polarized spiral antenna for Chinese compass navigation satellite system

In Chinese Compass Navigation Satellite System (CNSS for short), dual-band antennas are more attractive, because they can provide both navigation and communication services. In this paper, we present a dual-band dual-circular-polarized planar spiral-slot CNSS antenna. This antenna works at L band (1616 ± 5 MHz, left-handed circular polarization, LHCP) and S band (2492 ± 5 MHz, right-handed circular polarization, RHCP). Numerical results show that the impedance bandwidth (S₁₁ < -10 dB), 3 dB axial ratio bandwidth and antenna gain at L band are about 242 MHz, 79MHz and 4.92 dB, respectively, while the simulated impedance bandwidth (S₁₁ < -10dB0 dB), 3 dB axial ratio bandwidth and antenna gain at S band are about 180 MHz, 58MHz and 5.25 dB, respectively. An experiment was carried out to verify our design. Measured results show that impedance bandwidth (S₁₁ < -10dB0 dB) and 3 dB axial ratio bandwidth L band are about 300MHz and 14 MHz, respectively, while the measured impedance bandwidth (S₁₁ < -10dB0 dB) and 3 dB axial ratio bandwidth at S band are about 210 MHz, 10 MHz, respectively. The measured results basically agree with the simulated ones and meet the requirement of CNSS terminal antennas.