Research On Compact Multiband GNSS Microstrip Antennas And Their Arrays

GNSS is the abbreviation of the global navigation satellite system，which consists mainly ofGPS, GLONASS, Galileo and Beidou. In order to improve the reliability of the positioning, it requiresthe receiver antenna can operate on multi-frequency and be compatible with varieties of GNSSsiginals.The miniaturization of GNSS receiver antenna is a widespread concern in the importanttechnology.Therefore, research on compact multiband GNSS microstrip antennas and their arrays hasimportant theoretical significance and application value.This paper focusing on the issue carried out the following study:First of all, three novel compact multi-frequency GNSS microstrip antenna structure areproposed. One is a stacked square microstrip antenna using surface grooving technology. The antennasize is reduced by18%compared with the conventional stacked microstrip antenna. Anothermicrostrip patch antenna symmetrical loaded short stub is discussed. The simulated results andexperimental results show that the antenna can cover the1575MHz and1268MHz. The antenna size isreduced by23.6%compared with the conventional stacked microstrip antenna. On the basis of theabove work, a microstrip antenna symmetrical loaded T-shape stub is designed and researched,simulated results show that the antenna can cover the1575MHz and1268MHz.Secondly, the effect of square array and triangular array on the consistency of amplitude andphase of array elements is investigated. The simulated results show that the effect of the mutualcoupling between array elements on the receiving pattern of array element is obvious. The consistencyof amplitude and phase of array element of triangular array is better than square array of array element.The difference of amplitude and phase on the upper half-space is less than the other’s. Furthermore,with the change of incident interference direction, the effect of the difference of amplitude and phaseof array element of triangular array on the pattern nulling of array is researched. The results showwhen the incident interference comes from the upper half-space, spatial filtering effect of the array topattern nulling of array is larger than that from the lower half-space.Finally, a novel compact annual-ring reduced-surface-wave（RSW）antenna for GNSS receiversis developed. Four extra short-circuit vias are loaded on the annual-ring to restrict the surface wave.The right-hand circular polarization is achieved by two orthogonal feeding points. The simulationresults show that the backward and side radiated level in far field of the presented antenna is greatlylower than typical patch antenna, and its size is smaller than original RSW antenna.