Research Of Ka Band Mems Reconfiguurable Antenna:Design, Simulation, Fabrication And Measurement

Radio Frequency Micro-electro-mechanical System (RF MEMS) devices, compared with traditional electronic devices, obtain low insertion loss, high isolation, wide band, low intermodulation distortion, almost none driving loss, and low cost of integration. RF MEMS could realize the microminiaturization between each communicating module. In this paper, Ka-band radiation pattern reconfigurable antenna based on MEMS switches are studied.First, the research background of reconfigurable antennas is briefly introduced, as well as the advantages of those working in Ka-band.Second, in order to design our desired MEMS switches, the mechanical and RF model are analyzed. With the help of microstrip method and S parameter method, the capacitance of the MEMS switches in up-state are calculated. The microstrip method takes fringe effects into consideration to achieve a higher precision. Down-state capacitance is easily obtained, with which the inductance of MEMS switches can be calculated by resonance method. The paper also discusses ways to manipulate the resonant frequency, e.g. changing electrode area, dielectric material, beam structure, sector size, etc. Several MEMS switches are proposed.In addition, the basic structure of antennas is designed with ideal MEMS models. The current distribution on the patches are analyzed. Through sweeping several dimension parameters, their influences on the antenna resonance are obtained. The effects of parasitic patches on antenna resonance are, too, studied. At last, ideal models are replaced with actual MEMS switches. Both the two situations are discussed.Finally, both fabrication and measuring methods are proposed. Fabrication includes fabrication step design and layout design. In this paper, a multi-gelatinization method is proposed to flatten MEMS beams to achieve better performance. The reason that a specific measuring method is required is that the size of each antenna unit is too small and there does not exist microstrip input for measuring equipment. The limited dimensions result in incompatibility with SMA adaptors, while microstrip inputs result in incompatibility with probes.