A Study Of Surveying Antennas Based On Satellite Navigation System

In Satellite Navigation surveying, antenna phase center and multipath interference are the major error sources. Based on the above background and microstrip antenna, this thesis focuses on the derivation,calculation and verification of antenna phase center, the multipath rejection of choke ring antenna and antenna using EBG. This thesis contains four sections:1.Based on Satellite Navigation surveying, a RHCP patch antenna of double feeding points is designed. The antenna can work normally in RHCP and the axial ratio is less than 4 d B in concerned angles.2.The relationship and expression between phase center and far field phase distribution is built. The three-dimensional(3D) and two-dimensional(2D) apparent phase center(APC) are also calculated. The far field phase distribution and MATLAB are used to calculate the 2D APC, what is verified then. Far field phase distribution of the updated antenna using the APC varies 0.84 deg,while the original 9.53 deg.3. Surface impedance model is used to analyze choke ring to find the basic rules of deciding the size, and then three-dimensional(3D) choke ring antenna and two-dimensional(2D) choke ring antenna are designed. The capability of multipath rejection and far field phase distribution are analyzed among 3D choke ring antenna,2D choke ring antenna and a separate antenna. The results show that the two-dimensional choke ring antenna has a strong multipath suppression, three choke ring antenna with a strong multipath rejection is basically the same amount of fluctuation of the phase distribution with a microstrip antenna alone.4. Two properties of EBG structure are studied: frequency band gap characteristics and phase characteristics of the band gap, and a microstrip antenna loaded EBG structure with multipath rejection is designed using frequency band gap or to say surface wave suppression characteristics. The capability of multipath rejection is analyzed among 3D choke ring antenna,2D choke ring antenna and the microstrip antenna loaded EBGstructure. The results show that the microstrip antenna loaded EBG structure has the same capability of multipath rejection with 3D choke ring antenna, but does have miniaturized advantages of small size, light weight, etc.