Research On Terahertz Multiplier And Mems Filter Technology

Terahertz(THz) wave is between millimeter wave and infrared. the low frequency range of THz wave is connected with millimeter wave, and the high frequency range is connected with infrared. Because THz wave is still not fully developed, it is a frontier and hot issue in academic research. THz wave has many special features like strong penetrability, low photon energy etc. These features make THz wave has unique academic value and broad application prospects on object image, environmental monitoring, radio astronomy, satellite communications and military radar. THz technology is regarded as one of the top ten technologies to change the world.THz transceiver module almost determines the application prospect of terahertz technology, while THz source is the key component of the THz transceiver module. There are many ways to gain THz source, they can be generally divided into two types of based on optics and electronics. This thesis focuses on THz multiplier source based on schottky diode. Compared with other methods of generating THz source, this method has the advantage of small volume, low power consumption, easy to integration and operating at room temperature environment.To sum up, this thesis is based on the modeling of schottky diode, and then different structure multipliers are applied to get THz wave.THz planar schottky diode is the key device of THz frequency multiplier, modeling of the diodes is crucial to multiplier’s performance. At first, the equivalent circuit model of the diode is studied, and then the three-dimensional electromagnetic model based on diode physical structure is proposed. In addition, by studying the diode’s measured data, the equivalent circuit model is improved that can simulate the diode’s performance more accurately.This thesis proposes a novel frequency multiplier simulation method. The method is based on three-dimensional electromagnetic model, combines fieldsimulation and circuit simulation, simulates multiplier as a rounded system. Wave Ports are set not only at outside of the model but also inside of the model. Through those outside ports linear circuit of the multiplier can be connected, through those inside ports nonlinear circuit of the multiplier can be simulated. By this method, the simulation can be more accurate. Three types of 220 GHz multipliers are designed and measured, also the performance deterioration caused by machining and assembly error is quantitative studied.Moreover, a novel structure of waveguide filterwith circular cavities is proposed. The characteristic of micro-electro-mechanical system(MEMS) technology is studied Three THz waveguide bandpass filters based on micro-electro-mechanical technology are designed and fabricated. Simulation results consistent with measured results, the 400 GHz filter has a bandwidth of 24 GHz and an insertion loss of 1.9dB, the 900 GHz filter has a bandwidth of 35 GHz and an insertion loss of 2.4dB. The circular resonant cavity structure reduces the demand for machining, and improves the tolerance. The structure of waveguide filter is simple and reliable, can be used in many kinds of THz circuits.