Research On The Designs And Simulations Of Circularly Polarized Printed Antennas

With the rapid development of wireless communication technology, theantennas are widely used and many important technical progresses are achievedbecause that they are the indispensable devices for the wireless communicationequipments. The circularly polarized antenna is a common antenna type in manyradar systems, navigation systems, satellite communication systems and remotecontrol and remote telemetry systems. The circularly polarized antenna can receivethe spatial electromagnetic wave favorably and suppress the reflected interferenceclutter of the rain and fog. The research of circularly polarized antenna with lowprice, small size and low profile has important practical value. For this, thisdissertation designed and simulated three kinds of circularly polarized antennas forthe printed antennas in order to exploit their working performances and provides afavorable technical basis for their practical engineering applications.Firstly, a circularly polarized microstrip patch antenna loaded by slots wasstudied, and its working principle and radiation performances were analyzed. Forthe working frequency of1.6GHz, a specific circularly polarized microstrip patchantenna was designed according to the reference. The structure and parameters weredesigned and optimized through the electromagnetic simulation software, and theparamters which can meet the requirements were obtained. The specific simulationresults were given. The simulated gain at working frequency was2dBi and the axialratio (AR) was1.5dB.Secondly, a circularly polarized microstrip patch antenna loaded by parasitemetal ring was designed and simulated. For this antenna, the working frequencyband width of circularly polarized microstrip patch antenna can be increased tosome extent. According to the corresponding to reference, the structure andworking principle of this antenna were studied and mastered. The specific structureof a circularly polarized microstrip patch antenna loaded by parasite metal ring wasdesigned and the designed parameters were given for the frequency of3GHz. theradiation performances of this antenna was simulated through the electromagneticsimulation software and the simulated gain at working frequency was8dBi and theaxial ratio (AR) was1.5dB, what’s more, the good patterns were also obtained. Finally,. a circularly polarized ring antenna fed by co-planar waveguide (CPW)was designed and simulated. The radiation part of this antenna is mounted on oneside of the dielectric substrate and the circularly polarized radiation mode isgenerated by the ellipse feeding structure, so it has simple structure and it is easy tofabricated and feed. Similarly, based on the structure and principle of this antenna,a circularly polarized ring antenna with the frequency of2.7GHz was designed andthe radiation performances including gains, patterns and impedance were simulatedand analyzed. The simulated gain at working frequency was3dBi and the axial ratio(AR) was1.5dB, which can meet the anticipated design requirements.This dissertation study and master the development method of the circularlypolarized printed antenna through the analysis, design and simulation of three kindsof the circularly polarized printed antennas. The author’s engineering experiencewas also improved, which can provide a basis for the further work.