Research On Frequency And Pattern Reconfigurable Microstrip Antenna

With the development of miniaturization, multi-function, multi-band modernwireless communication system, more demands are for antenna which is used totransmit and receive wireless signal. As a novel antenna, compared with theconventional antenna, reconfigurable microstrip antenna has many advantages, suchas small volume, light weight, low profile, easy of integration and so on, has drawnmuch attention.Operation frequency and radiation pattern are two important characters ofantenna. Taking full use of reconfigurable mechanism of antenna to achieve frequencyand pattern reconfigurability has been a research hotspot in the field of reconfigurableantenna study. Frequency and pattern reconfigurable antenna not only is of thefrequency reconfigurable antenna’s merits but also pattern reconfigurable antenna’smerits, which can be used to improve the system gain and spectrum utilization, avoidnoise interference, save energy, enhance the privacy and security of system. It hasbecome a hotspot in the field of reconfigurable antenna research.Based on adequately understanding and mastering the domestic/abroad researchprogress and design method of reconfigurable antenna, also allowing for wirelesscommunication systems’ demand for the low profile antenna, a microstrip antennawith frequency and pattern reconfigurable characteristics is designed, whose structureis similar to a tuning fork. By controlling the states of the corresponding switches, thedesigned antenna can achieve two directional radiation patterns switching during twofrequency-bands of2.69-2.81GHz and3.18-3.59GHz. In the meantime, the designedantenna also can get the four switchable operation frequency-bands of2.17-2.58GHz,2.76-2.86GHz,3.13-3.79GHz and3.68-4.42GHz while keeping the omnidirectionlradiation pattern in the elevation plane nearly unchanged. Then, a frequency andpattern reconfigurable microstrip antenna, which can realize six directional mainbeams switching during two frequency-bands of4.73-5.63GHz and5.07-6.88GHz, isproposed. And a relatively good impedance matching, narrow half power beamwidth(HPBW) and high gain are obtained at the two resonance frequency points of5.05GHz and5.40GHz.Finally, the antenna whose structure is similar to a tuning fork is fabricated andmeasured. The measured and simulated results agree well with each other, which verify the correctness and feasibility of antenna design.