Research Of MEMS Microstrip Antenna Array On Double-layer Silicon Wafers

Antenna is one of the indispensable component of the wireless communication system.The requirements of the performance and size of the antenna is improved with thedevelopment of radio technology and manufacturing technology. Microstip antennas arewidly used in many small wireless-communication systems because of its characteristics oflow profile, small volume, light weight and easy conformal with the carrier. However, thetradional microstrip antenna with the Teflon as the substrate is difficult to meet the needs ofthe wireless communication system miniaturization and high performance development,because the antenna has a narrow band, low gain, easy to produce surface waves, hard tointegrated with circuits and other defects.MEMS (Micro Electro-Mechanical System) can provide important technical supportfor wireless communication system miniaturization and high performance developmentbecause of its characteristics of miniaturization, integration, mass production and lowcost.A new direction of microstrip anteena has shown which is combining the MEMStechnology to manufacture a large number of antennas conveniently to meet the need ofprojects. With the development of MEMS technology as well as application in othermicrowave devices, the miniaturization trend of wireless communication system isintegrating the microstrip antenna and other devices directly by using MEMS technology.The microstrip antenna designed in this paper is working at10GHz, belongs to X band.The substrate of antenna is using high resistivity silicon and low resistivity silicon doublelayer composite structure to obtain a suitable dielectric constant and then improve thebandwidth characteristics of the antenna. A U-shaped dumbbell DGS (defected groundstructure) is designed in the antenna ground by etching process to improve the transmissioncharacteristics of the antenna. The anti-interference of the antenna is enhanced by applyingthe bandstop characteristics of DGS in the antenna design to suppress the harmonics. Basedon these, two microstrip antenna array has designed which has two units and four unitsrespectively. In four units microstrip antenna array, a better radiation is obtained by usingplanar distribution, lateral microstrip line feeding and indentation measure in front-sidefeed line. The results of designed antenna show that the four units antenna array has anrelative impendence bandwidth of17.3%(VSWR≤2) and a gain of10.9dB while its area is39.6mm*45.69mm and height is1mm. Obviously, the results have demonstrated that the four units antenna array of double silicon layer composite substrate possesses excellentcharacteristics of bandwidth and gain, and meets the miniaturization requirement ofwireless conmmunication system.