發(fā)布時(shí)間：2018-05-06 11:37

  本文選題：射頻微機(jī)電 + 諧振器��； 參考：《電子科技大學(xué)》2015年碩士論文

【摘要】：隨著電子系統(tǒng)對(duì)高性能、小型化器件需求的逐步增長(zhǎng),MEMS振蕩器憑借其高Q值、易集成、抗沖擊等優(yōu)異性能成為研究熱點(diǎn)。本文旨在探究高頻MEMS振蕩器的性能,而諧振器作為振蕩器的核心部件,自然成為研究的重點(diǎn)。文中設(shè)計(jì)了一種新型的帶有可動(dòng)電極的10MHz MEMS方塊諧振器。著重研究了降低諧振器動(dòng)態(tài)阻抗的移動(dòng)電極法。電極與諧振方塊初始間隙為2.5μm,當(dāng)加載60V偏置電壓后,通過(guò)靜電力作用使二者間距減小至0.5μm。此時(shí),通過(guò)ANSYS諧波仿真得知諧振器動(dòng)態(tài)阻抗減小至初始值的1/626。在不增加工藝難度的前提下,將器件的深寬比從10:1提升到50:1。基于體硅加工的工藝特性,給出了諧振器的微加工流程,利用L-EDIT完成了固定電極與可動(dòng)電極兩種諧振器的版圖設(shè)計(jì),實(shí)現(xiàn)了兩種類(lèi)型諧振器的加工,并采用真空探針臺(tái)完成了諧振器裸片測(cè)試,定性地分析了其諧振器諧振頻率產(chǎn)生0.552MHz偏移的原因。針對(duì)諧振器工作的真空環(huán)境要求,研究了其封裝所需條件,對(duì)諧振器進(jìn)行了金屬封裝。運(yùn)用矢量網(wǎng)絡(luò)分析儀完成了封裝后諧振器的測(cè)試,評(píng)估了金屬封裝對(duì)諧振器性能的影響。采用機(jī)電類(lèi)比法,根據(jù)諧振器機(jī)械特性與電氣特性之間的映射關(guān)系,將諧振器的機(jī)械集總參數(shù)模型轉(zhuǎn)化成了對(duì)應(yīng)的電氣集總等效電路模型。針對(duì)諧振器電路模型的輸出特性,引入了差分法消除諧振器饋通電容的方法。依據(jù)測(cè)試數(shù)據(jù),通過(guò)仿真擬合出諧振器RLC電路模型中各參數(shù)值。選用性能比較優(yōu)異的固定電極MEMS方塊諧振器進(jìn)行了MEMS振蕩器的設(shè)計(jì)。由ADS電路仿真得MEMS振蕩器的主要性能如下:輸出信號(hào)頻率為9.448065MHz,輸出信號(hào)功率14.205d Bm;各階偶次諧波輸出功率均低于-350dBm,幾乎可以忽略不計(jì);MEMS振蕩器輸出噪聲性能:-100.370dBc/Hz@0.1Hz,-103.565dBc/Hz@1Hz,-120.197dBc/Hz@10Hz,-122.784dBc/Hz@100Hz,-122.777dBc/Hz@1kHz。
[Abstract]:With the increasing demand of electronic systems for high performance and miniaturization devices, MEMS oscillators with high Q value, easy integration, impact resistance and other excellent properties have become the focus of research. The purpose of this paper is to explore the performance of high frequency MEMS oscillators, and the resonator, as the core component of the oscillator, naturally becomes the focus of the research. A new type of 10MHz MEMS square resonator with movable electrode is designed in this paper. The method of moving electrode to reduce the dynamic impedance of resonator is studied emphatically. The initial gap between the electrode and the resonant square is 2.5 渭 m. When the bias voltage of 60V is loaded, the distance between the electrode and the resonator is reduced to 0.5 渭 m by electrostatic action. At this point, the ANSYS harmonic simulation shows that the dynamic impedance of the resonator is reduced to 1 / 626 of the initial value. Without increasing the process difficulty, the aspect ratio of the device was raised from 10:1 to 50: 1. Based on the process characteristics of bulk silicon machining, the micromachining process of resonator is given. The layout design of fixed electrode and movable electrode is completed by using L-EDIT, and two types of resonators are machined. The vacuum probe table is used to test the resonator's bare chip, and the reason of the 0.552MHz shift of the resonator's resonance frequency is analyzed qualitatively. According to the vacuum environment requirement of the resonator, the conditions of its packaging are studied, and the metal packaging of the resonator is carried out. The effect of metal encapsulation on the performance of the resonator was evaluated by using vector network analyzer. According to the mapping relationship between mechanical and electrical characteristics of resonator, the mechanical lumped parameter model of resonator is transformed into the corresponding equivalent circuit model of electrical lumped circuit by electromechanical analogy method. According to the output characteristics of the resonator circuit model, a differential method is introduced to eliminate the feed-through capacitance of the resonator. According to the test data, the parameters of the resonator RLC circuit model are simulated. The MEMS oscillator is designed by using a fixed electrode MEMS box resonator with excellent performance. The main performances of the ADS oscillator are as follows: the output signal frequency is 9.448065MHz, the output signal power is 14.205dBm, the output power of every order harmonic is lower than -350dBm, and the output noise performance of the MEMS oscillator is almost negligible: -100.370 dBc / Hz-103.565dBcHz-120.197dBc / Hz-122.784dBccP / Hz100Hz-122.777dBcHcP / HzP / HzP = 1kHz.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TN752
，

本文編號(hào)：1852163