Three RF Devices Study Of Phase Shifter,Mixer And Active Inductor

The thesis is mainly divided into three parts, the RF devices of phase shifters, mixers and active inductors.Nowadays, with the development of MEMS technology, MEMS phase shifter becomes one of the major research MEMS devices and gained widespread attention. The thesis studies the capacitive MEMS shunt switch and metal-contact Cantilever MEMS series switch, including the basic theories and principles. Design the capacitive MEMS shunt switch with return-loss less than-20dB, insertion-loss less than 1dB, the drop-down voltage is about 80V, switching time is about 16μs, consistent with most of the MEMS switch time of 10-50μs s range. Using the method of coating the low dielectric constant thin-layer insulationfilm on the signal line of the coplanar waveguide, M-I-M capacitor is formed between the MEMS bridge and signal line, the ratio of the capacitor of the down state and up state is increased, thus the phase shift of the unit length is raised. Designed to achieve 36°phase shift of the MEMS phase shifter.The mixer is an important block in receivers, the study has been one inportant issue of the RFIC design. The thesis studies the basic theories, performance, parameters and type of mixer. Final, design the microstrip passive double-balanced mixer used in receivers fron-end.Inductor is the important elements in electronic circuit design, widely used in filters, band-pass amplifiers and other high-frequency compensation circuit. Passive inductor with shortcomings of large-volume, low quality factor(Q), hard integration and miniaturization, but active inductor can solve this problem. So the main work is studied active inductor. The thesis base on the theory that the output of source follower amplifier acts like an inductor if the input is driven by a large resistor, a novel active inductor with improved quality factor(Q) is proposed, and the maximum Q can be 1055, at 3GHz and seriesed a resistor with 3.5 kΩ.Because of restrictions of many conditions, the research of this problem is still staying at a more shallow level, so the thesis puts forward the direction to do more research and develop of the problem. It sets matting for the future study and research of this topic.