Design And Research Of The Dual-band Microstrip Antennas Used In The Satellite Communications

Satellite communications have been more and more widely used in our social life and the demand for antenna used in the satellite communication is increasing rapidly.The antenna acting as the transceiver device of the communications has an important impact on the quality of air-ground communications.Now China's satellite navigation industry is booming and development of the Beidou system is an important milestone in China's wireless communication field.In order to meet the demands of China's satellite navigation,it's important for us to achieve multi-band,miniaturization and circular polarization of the satellite navigation antenna.For the need of satellite navigation,three dual-band circularly polarized antennas were designed.In view of the weight,low profile and ease of circular polarization,the micro strip antenna was chosen here.First,due to the simplicity of the layered structure,a dual-band circularly polarized antenna that can cover the B1,B3 band of the Beidou system was designed.The circular patch antenna achieved the miniaturization through a combination of methods of high dielectric constant and surface meander.The size of the antenna was reduced by 45.1% and the gain increased slightly.The antenna covering the bandwidth of 1.245GHz-1.269 GHz and 1.554GHz-1.602 GHz,achieved circular polarization by a single feed.The right-hand circular polarization was achieved by way of introduction of perturbation on the patch and the axial ratio was below 3dB at the B1 and B3 band.The RHCP highest gain was over 3dB at the elevation of 90o and 0dB beam width is greater than 100o.The antenna had a good Omni-directional performance and is easy to receive satellite signals.Meanwhile,the front to back ratio was greater than 20 dB,which can effectively suppress interference from the rear.The antenna can meet the applicable standards of satellite antennas.In order to achieve further miniaturization of the antenna,two satellite antennas were designed using the form of tiny patch.Dual-band was realized by introducing micro strip minor in patch,and the RHCP was achieved by the vertical patch and the micro strip feeding.The first antenna can cover the B1 band of the Beidou system and the L2 band of the GPS.The RHCP highest gain was over 1.5dB at 1.20 GHz,1.560 GHzand 1.580 GHz.The structure of the second antenna is slightly different from the first,which can cover the B3,B1 band of GNSS,The RHCP highest gain was over 1.5dB at 1.270 GHz,1.560 GHz and 1.580 GHz.The two antenna have a wide axial ratio bandwidth and-10 dB bandwidth,and the antenna can meet the applicable standards of satellite antennas.