Research Of Multi-band And Circular Polarization Of Handset Planar Inverted-F Antenna

Mobile communication systems have experienced enormous growth in recent years. As the most important radio-frequency front device, handset antenna is developing into miniaturization, built-in, multi-band and intelligence. Microstrip antennas have many features like small size, light in weight, low profile and conformal, so they become the optimal choice for handset internal antennas. Unfortunately, some shortcomings of microstrip antennas such as low gain, small bandwidth, etc, make them unfit for practical application.First this thesis describes the basic theory of microstrip antennas, summarizes and analyzes the technology of miniaturization, multi-band and broadband. Then radiation principle and electrical performance of the fashionable planar inverted-F antennas (PIFA) is discussed and a novel handset terminal antenna PIFA is designed with many technologies of miniaturization, multi-band and broadband. The proposed antenna is compact and easy to build, and it also can operate in GSM900, DCS1800 and ISM2450 bands, which allows the design to be satisfied with wireless and portable communication systems. Last discusses the theory and realization method of circular polarization (CP) for microstrip antennas in details, and proposes a PIFA with CP radiation based on.research of dual- polarization(vertical and horizontal).The dimension of the presented antenna is designed and optimized with EM simulation software HFSS from Ansoft company. The influence of characteristic data as primary parameters modifying is discussed particularly(including resonant frequency, bandwidth, directivity diagram, impedance chart, 3dB axial ratio bandwidth, etc).