| With the rapid development of wireless communication technology, the civilization research of microwave and millimeter-wave technology has been strengthened greatly. Millimeter-wave planar circuit is one important part of millimeter-wave technology. In recent years, many new technologies, such as MCM, MEMS, SOC, EBG, etc, have been applied into the millimeter-wave planar circuits. All these new technologies have improved the performance of the civilian millimeter-wave radar and RF communication system as well as induced the volume and power consumption of these systems. The research of this dissertation focuses on three aspects: the microstrip array antenna of 35GHz, millimeter-wave MEMS switch and the Photonic Bandgap(PBG) filter and microstrip array antenna on PBG substrate. The main context of this dissertation includes:1. The situation of millimeter-wave automobile collision warning radar (CWR) is introduced, especially pictured the history of antenna of CWR. The structures and principle of RF MEMS switch are introduced in detail. It is provided about the background, principle and application of Photonic Crystal.2. Based on the requirement for the antenna of CWR, such as thin beam, high gain, little volume and planar structure etc, the design method of microstrip array antenna is research especially. Three different kinds of array antenna are designed, including microstrip linear array antenna, series-fed rectangle array antenna and shunt-fed rectangle array antenna. As the result of experiment, the beamwidth of 8 8 shunt-fed array antenna is 5 , side lobe level is 17dB and the gain is 22dBi. It is the first time to apply the microstrip array antenna in SAE-100 radar system. The returning wave is good, which has the amplitude of 0.03V, as the distance is 2m.. The results show that this shunt-fed array antenna can be used as the CWR antenna for a single object detecting. The excellent performance of SAE-100 with microstrip antenna is one of the important steps for the miniaturization and practical application of this system.3. The principle of millimeter-wave MEMS switch is introduced and two different structures of MEMS switch are given. A new millimeter-wave MEMS switch, single pole double throw (SPDT) MEMS switch, is designed. Using the HP ADS, the author has optimized the value of Con, Coff, Con/Coff and R, which are the main parameters of the RLC circuit of SPDT MEMS switch. At the same time, the relationship between the action voltage and the material of air bridge is analyzed. A new method, the wet eroding, is applied to fabricate the air bridge. This method can improve the rate of finished product of air bridge. The picture and tested results is provided in this article.4. The Coplanar Waveguide (CPW) transmission line is used commonly in the millimeter-wave planar circuit. It is very valuable to research the low-loss CPW line for millimeter-wave planar circuit. In this article, some novel methods are applied to reduce the transmission loss of CPW line. As the results of experiment, the loss of CPW on high-resistivity GaAs is less than 0.6dB/mm. On the other hand, for the CPW on the same substrate, there are two means to cut down the loss, the first is to electroplate the metal of CPW to 4-5 times thickness of skin depth; the second is to erode somewhat the substrate material between the metals. All will reduce the loss about 0.2dB/mm respectively. For the CPW line on low-resistivity Si, polyimide is used to reduce the loss as well as electroplate the metal. The transmission loss of CPW on low -resistivity Si, which is applied the two means at the same time, will be 2-3dB than the loss of the line without any means. The research can provide reference for cutting down the cost and power consumption of RF IC.5. Photonic Crystal (PC), which is invented to inhibit the spontaneous emission in the end of 1980s, is a new kind of concept and material. Science has ranked photonic crystal as one of the six most important fields. A... |
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