Research On Multiband Antenna Array For Global Navigation Satellite Systems

Global navigation satellite system (GNSS) receivers are increasingly used in military and civil domains and is mainly used in navigation and positioning, precise timing, emergency communications, transportation,dispatching, search and rescue, marine fisheries, real-time geographic information query and other areas. Multimode satellite navigation receivers can improve the positioning accuracy, reliability and safety, the main development trend of the navigation satellite technology is the multi-mode satellite navigation. As the key component of multi-mode satellite navigation receiver, multiband circularly polarized antenna is applied to a wider range of scenarios.The multiband antenna array for global navigation satellite system can improve the accuracy and robustness of the navigation system, but because of the demand for the miniaturization and portability, the reduced inter-element separation introduces strong mutual coupling between the elements, and degrades the radiation performance of the antenna. Thus leads to the research and implementation of the decoupling network technology of the antenna array.On the basis of theoretical analysis, a single feed triple band circularly polarized microstrip antenna array for GPS application, covers GPS L1(1.575GHz), L2(1.227GHz) and L5(1.176GHz) frequency bands,is designed, simulated and tested in this article. The antenna array consists of four radiating elements. The antenna element is fed by a coaxial probe and is made up of three square patches stacked on one another to make the antenna work in three frequency bands. The inter-element separation is 90mm.In order to reduce the ground coupling,introducing four additional rectangular slits in the ground-plane to mitigate the inter-element coupling and make the 3dB axis ratio bandwidth and the -10dB impedance bandwidth cover GPS L1, L2 and L5 frequency bands. The design and simulation of the antenna array are completed in the electromagnetic simulation software HFSS and the test performance of all aspects of the antenna array can meet the requirements of GPS navigation applications.When the inter-element separation is reduced to 65mm,the coupling between elements become strong. In this context, the design of single band decoupling network which is composed of microstrip line is necessary. In this paper, a single feed triple band circularly polarized microstrip antenna array with single band decoupling network with single is investigated. It reduces the mutual coupling between the elements below - lOdB in the GPS L1, L2 and L5 bands, which is basically required for the navigation systems.