The Implementation And Research On The Key Components Of Microwave Receiver Front-end Based On The RF MEMS Technology

The front-end is the basic interface between a typical communication system and itsenvironment. These front-end data processing, storage and transmission technologyare becoming more and more important. The high-density multi-functional integration,minimization, low-cost radio communications technology terminals will be the maindirection of development. The current communication system still have a lotindispensable chip discrete components, such as inductors, variable capacitors, filters,coupling, phase shifter, switch array, and so on, becoming a bottlenecks of furtherreducing system size. Furthermore, modern communication networks have tosuppress the harmful effects of the interference from other users who share the samechannel and the self-interference due to multi-path propagation. Additionally,securing the transmitted information from the unintended listeners and alleviating theeffects of communication jammers are two equally important issues for the currentand the coming generation of the tetherless (terrestrial wireless and satellite)communication systems. All these vital requirements impose significant challenges onthe current technology and illustrate the need for new designs and advancedarchitectures. In light of this situation, this paper applied RF MEMS technology to themicrowave, millimeter wave RF front-end system, focusing on research of the keycomponents(RF MEMS reconfigurable antenna, reconfigurable filters) of the RFfront-end. The main contributions are as follows:1. Resting on present research status of RF-MEMS antenna and filter, systematicallytheoretical analysis and profoundly experimental research on electromagneticradiation and coupling, mathematical modeling and numerical simulation,parameter optimization under the micro-scale MEMS RF MEMS antenna, thefilter have been presented in this thesis using slow-wave theory and application ofmicrowave electromagnetic simulation software HFSS. The micro-machiningfrequency reconfigrable antennas and filter have been fabricated successfullyusing RF MEMS switch and the surface micro-machining technology, but antennaradiation patterns unchanged.2. In this paper, we first present that the miniature re-configurable antenna wasdesigned and fabricated on the high resistivity Si substrate working on theKu-band, and is common planar waveguide-fed antenna. Its size is 10×10mm~2.The use of the antenna switch can change the length of radiation, thereby enablingslot antenna the resonant frequency change, and the antenna radiation patternsunchanged. Such antenna, using a surface micro-processing technologyproduction, changed the traditional antenna to the basement as PCB antenna production methods. Before and after reconfigurable antenna resonant frequencyis of 12.7 GHz and 11.6 GHz.3. The Sierpinski, Minkowski, Single-Arm Spiral, Double-Ring four small single-fedreconfigurable silicon-based MEMS fractal antenna with size 5×5mm2 have beenresearched and realized using fractal theory. They radiation patterns unchangedwhen frequency changed. Minkowski, Double-Ring reconfigurable antenna isproposed for the ftrst time in this paper. After testing, before and after theReconstruction, Single-Arm resonant frequency points are far apart, which is 9GHz and 30.3 GHz, 5.2 GHz and 22.5 GHz, respectively, but Double-Ring is16.9GHz and 25.8GHz, 7.3GHz and 20.2GHz. Sierpinski and Minkowski have2.58 dBi and 2.5 dBi of good gain. Double-Ring best gain is of 0.15 dBi forSingle-Ann Spiral compared with -3.9 dBi. The number of experimental samplesantenna test, this paper studies these types of antennas with good reproducibility.4. This paper presents a low-pass filter lumped parameter model. The variousparameters impacting properties of the filter were quantitative analyzed. TheS-parameter was simulated in HFSS using various components in models. Theoptimizations of low-pass filter S parameters had completed by adjust the moreimpacting parameters. The ripple attenuation characteristics of the optimized filterprototype is good. This filter designed using slow wave and fractal theory, sizeand loss have become smaller. The microwave MEMS-small filter can bemanufactured by surface micro-processing technology. The measured results ofthe reconfigurable low-pass filter show the 3dB cutoff frequency change from 19to 11GHz with very small change in the average insertion loss from 1.3 to 1.9 dB.The chip size of the low-pass is 4.0min×1.6mm. Its the out of band attenuation isabout 20dB in 40GHz.5. This paper presents a set of methods and technology line for production ofmicrowave RF front-end RF MEMS key components, including reconfigurableantenna, fractal filter. This paper also designed the structure of several differentsizes larger MEMS switch. Among them, the larger capacitance switches size isthe 520×150(μm), multi-contact switch to 380×150(μm). Preparation process, wehad done a focus on technology of the use of thick plastic (plastic), and polyimidesacrificial layer material, the first layer to the expense of drying, curing film andetching.This paper presents research on the key RF MEMS components of RF front-end, suchas reconfigurable antennas, reconfigurable filters. This will play a positive effect forthe construction of microwave RF front-end. But the ultimate realization ofmicrowave RF receiver front-end circuit based on MEMS technology still need to domore.