Research On Miniaturized Slot Helix Antenna For Global Navigation Satellite System Terminal

The antenna is one of the key components of the global navigation satellite system,because its performance directly affects the quality of the terminal communication.The quadrifilar helix antenna is widely used in the field of satellite navigation due to its good directivity,circular polarization,wide beamwidth and other properties.This paper studies the miniaturized slot helix antenna for global navigation satellite system terminal.The main research contents are as follows:1.A miniaturized square quadrifilar slot helix antenna for satellite navigation terminal is presented.The antenna has the shape of a quadrangular prism shape.Four slot helical arms are printed on the outer surface of the substrate,realizes circular polarization of the helix antenna through a simple feeding network.The overall size of the proposed antenna is 0.123l₀′0.123l₀′0.276l₀（l₀is the free-space wavelength at the center frequency of BDS B1）.The measured result of the impedance bandwidth is120MHz（1.512GHz-1.632GHz）,and the measured result of the 3dB axial ratio bandwidth is 53MHz（1.556GHz-1.609GHz）,the gain at the center frequency of BDS B1（1.561GHz）and GPS L1（1.575GHz）are 4.31dBi and 4.84dBi respectively.2.A compact helix antenna with wide axial ratio bandwidth using a spiral microstrip coupling feedline is presented.The antenna uses a spiral microstrip coupling feedline,realizes the effective radiation of the helix antenna through the coupling effect with the slot.Four slot helical arms are printed on the outer surface of the substrate,and the end of the slot is extended to the top surface of the proposed antenna for the compact size.The overall size of the proposed antenna is 0.156l₀′0.156l₀′0.182l₀（l₀is the free-space wavelength at the center frequency of BDS B1）.The measured result of the impedance bandwidth is 137MHz（1.525GHz-1.662GHz）,and the measured result of the 3dB axial ratio bandwidth is 133MHz（1.497GHz-1.63GHz）,the gain at the center frequency of BDS B1（1.561GHz）,GPS L1（1.575GHz）and GLONASS L1（1.602GHz）are 4.65dBi,5.13dBi and 4.41dBi respectively.3.A wideband circularly polarized slot helix antenna is presented.Two sets of slot helical arms are printed on the outer surface of the substrate,the feeding network is a folded microstrip line that is printed on the inner surface of the dielectric substrate,and the wide impedance bandwidth and axial ratio bandwidth of the antenna are realized by coupling feeding to each slot.The overall size of the proposed antenna is0.111l₀′0.111l₀′0.221l₀（l₀is the free-space wavelength at the center frequency of BDS B2）.The measured result of the impedance bandwidth is 620MHz（1.158GHz-1.778GHz）,and the measured result of the 3dB axial ratio bandwidth is 785MHz（1.133GHz-1.918GHz）,the gain at the center frequency of BDS B1（1.561GHz）andBDS B2（1.207GHz）are 3.81dBi and 3.63dBi respectively.