Development of a frequency tunable PIFA with antifilter function base on microelectro mechanical system(MEMS) technology

• Main Authors: Ching-Chi Lin, 林敬基
• Other Authors: Jung-Tang Huang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/wtqxj2

碩士 === 國立臺北科技大學 === 製造科技研究所 === 93 === This thesis presents the development of a frequency tunable PIFA with antifilter function base on micro electro mechanical system (MEMS) technology. For the theorem of antenna with antifilter function, we deduce the B-type Antifilter operator and C-type Antifilter operator. We found that the -3dB bandwidth of bandpass filter is equal to antenna`s be the design rule of designing antifilter antenna. Based on the design rule we can design an antifilter antenna which -3dB bandwidth matches the standard of bandpass filter in a RF receive front-end. So we not only reduce the area of RF receive front-end but also avoid the insertion loss and insufficient attenuation problem of the bandpass filter. The rationale of tuning frequency for the antenna is by placing small tuning strip beside the radiation patch and by installing the MEMS Switch to control the connective state between the tuning strip and the radiation patch. The dimensions of the antenna can be changed to obtain variable resonant frequency when the switch operates to connect the tuning strip and the radiaton patch. First the bandwidth variation on different substrate thinkness of antennas and the frequency variation of antennas by installing the contact strip instead of MEMS switch are simulated and calculated by the full-wave numerical analysis tool IE3D. Then we fabricate the frequency tunable PIFA on FR4 substrate and measure the S parameters by network analyzer HP8722ES and compare with the results of simulation. Finally, the MEMS switch fabricated by TSMC 0.35um process is applied to frequency tunable PIFA. The frequency tunable PIFA is made by utilizing the thinkfilm printing technique on the ceramic substrate and package it with MEMS switch to complete the frequency tunable PIFA with antifilter function.