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类型 基础研究 预答辩日期 2018-03-27
开始(开题)日期 2015-09-08 论文结束日期 2018-01-08
地点 南高院403 论文选题来源 其他项目    论文字数 7 (万字)
题目 微电子机械微波通讯信号集成检测系统的研究
主题词 微波信号,MEMS,微波功率传感器,集成检测,GaAs MMIC
摘要 在微波信号检测中,微波的功率、频率和相位是三大基本的测量参数,微波信号检测广泛应用在幅移键控(ASK)、频移键控(FSK)、相移键控(PSK)、微波定位、天线相位方向图的测试和近场诊断等微波通讯系统。这些系统在实际应用中迫切需要重量轻、体积小、功耗低和集成度高的电子装备。现有的微波功率、相位和频率检测器都为单个独立电路,这些分立器件不仅具有体积较大的缺点,而且无法完成对同一时刻的微波信号的功率、相位和频率的检测。为此急需一种可以同时对三种微波参量实现集成检测的系统来满足微波通讯领域的应用需求。 针对这些需求,本文基于单个分立的检测器的研究,完成了微电子机械微波通讯集成检测系统的设计理论和实现方法的研究,主要内容包括: (1) 针对电容式MEMS微波功率传感器在大功率下非线性的问题: 提出了一种最大功率达到4W的电容式MEMS微波功率传感器,应用Ansys HFSS软件对电容式MEMS功率传感器的结构进行了模拟,得到了MEMS梁表面的电场和磁场分布,从而确定了有效传感范围;并利用Ansys FEM软件分析电容传感器的机械性能,得到MEMS梁在4W输入功率下的位移分布,对传统的微波-力-电转换模型进行了第一次修正;在此基础上,进一步考虑大功率输入下电容增大所导致的信号反射,进行了第二次修正;最后,通过对该电容式MEMS功率传感器的大功率下输出特性进行了测试,验证了经两次修正后的传感器非线性模型的有效性,为大功率的电容式MEMS微波功率传感器的研究奠定了理论基础。 (2) 针对MEMS微波相位检测器相位全周期和大功率信号检测的问题: 基于GaAs MMIC工艺制备了一种基于MEMS功率传感器的MEMS微波相位检测器,测试表明,该MEMS微波相位检测器的相移测量结果与一个完整周期的计算结果吻合良好;在输入23dBm功率10GHz频率下,由热电式和电容式两种MEMS功率传感器所测得的相位灵敏度分别为16.62μV/°和23.94aF/°;进一步,为充分研究性能良好的MEMS微波相位检测器的应用可行性,本文还对其进行了大功率下的相位检测,相移测试结果依然符合余弦曲线关系。电容式MEMS微波功率传感器弥补了热电式功率传感器处理高功率的不足,将MEMS微波相位检测器的动态范围扩大到4W。 (3) 针对MEMS微波信号检波器的问题: 提出了热电式、在线式和级联式三种基于GaAs MMIC工艺的MEMS幅度解调器,即MEMS检波器,这些检波器利用热电转换器和静电力执行器的平方律特性和低通特性。实验表明,热电式MEMS检波器可以实现载波频率为0.35-10GHz的幅度调制信号的直接检波,功率检测范围覆盖0-20dBm;在线式MEMS幅度检波器的回波损耗在0.01-10GHz频段内优于20dB,插入损耗小于0.5dB,并可以对幅度调制信号实现在线直接检波;级联式MEMS检波器具有高功率处理能力的优点,能够覆盖0-23dBm的功率范围。这三种MEMS检波器都具有无直流功耗的优势。 (4) 针对MEMS悬臂梁开关的介质层电荷注入相关的可靠性问题: 针对MEMS悬臂梁开关结构的介质层电荷注入所引起的可靠性问题进行了深入的研究,提出了一种平衡电桥表征方法,首先,建立了平衡电桥的等效电路模型,推导了平衡电桥法的精度公式。通过激光多普勒测速仪分析了悬臂梁的振动模态,确保了悬臂梁开关结构的机械对称性;利用函数信号发生器和示波器分析了悬臂梁开关结构的电学对称性;研究了直流电压条件下的电荷充电过程,实验结果表明,平衡电桥法的精度可以达到10Ω/fF,通过使用该方法可以观察到接触和非接触的充电过程,这两种充电效果可以根据拟合后的弛豫时间和拉伸指数因子来区分;在此基础上研究了26-33dBm功率26GHz频率RF信号下的介电层电荷充电过程,并对相应的机理进行了分析和讨论。实验结果表明,相比于直流电压,RF信号下的下介电层充电的效应十分有限。 (5) 针对MEMS微波通讯信号集成检测系统设计理论和实现方法方面的问题: 设计理论:本文首先通过n端口无源网络信号叠加合成过程,给出了n端口信号检测的通用公式,并由该通用公式推导出六端口微波信号集成检测系统的理论公式,从而为集成检测系统的拓扑结构设计提供依据;其次,在此基础上提出了基于幅度比值和相位比较检测频率的两种微波信号集成检测系统的结构,并且针对这两种微波信号集成检测系统分别利用Ansys HFSS软件进行了结构模拟,确定了这两种微波信号集成检测系统的最终结构尺寸。 实现方法:利用GaAs MMIC工艺制备了基于幅度比值和相位比较检测频率的两种微波信号集成检测系统。这两种微波信号集成检测系统首先利用幅度比值和相位比较法对待测信号的频率进行了检测,并且频率检测与功率无关;其次利用耦合的方法对待测信号的功率进行了检测,并且在测得频率的基础上对测试结果进行了校正,使得功率检测与频率无关;这两种微波信集成检测系统都利用正交双通道的方法实现了相位检测;进一步,这两种微波信号集成检测系统都可以对调幅信号实现直接检波;最后,利用微波网络理论,推导并计算MEMS微波传感器及其集成检测系统的S参数模型,为微波通讯系统中的嵌入式应用提供了有力的理论支撑。该MEMS微波通讯信号集成检测系统,实现了对同一时刻的微波信号的功率、相位、频率检测及调幅信号的检波;并且单片集成系统具有抑制加工工艺所导致的不对称偏差的优点,保证了检测系统内部的各个传感结构的一致性。 基于以上MEMS微波通讯信号集成检测系统的设计理论和实现方法的研究已获得多项中华人民共和国国家发明专利授权和受理(见成果表),具有自主知识产权,填补了国内MEMS微波通讯信号集成检测系统在设计理论和实现方法方面的空白。
英文题目 RESEARCH OF MEMS-BASED INTEGRATED DETECTION SYSTEMS FOR MICROWAVE COMMUNICATION
英文主题词 microwave signal,MEMS,integrated detection,microwave power sensor,GaAs MMIC
英文摘要 In the field of microwave technology,microwave power, frequency and phase are the main measurement parameters. Microwave signal detection is widely used in ASK, FSK, PSK, Microwave positioning, antenna phase pattern testing, near-field diagnosis. These systems are in urgent need of practical application of lightweight, small size, low power consumption, high integration of electronic equipment. The existing microwave power, phase and frequency detectors are discrete circuits. These separate devices not only have the disadvantage of bulky but also can not measure the power, phase and frequency of signals simultaneously. Therefore, an urgent need for a system that can achieve integrated detection of three microwave parameters to meet the application requirements in the field of microwave communication. In response to these needs, based on the research of discrete single detectors, the design theory and implementation of integrated detection system are completed. The main works are described as follows: 1. In term of non-linearity under high power for capacitive MEMS microwave power sensor: A capacitive MEMS microwave power sensor with a high-power handling of 4W is proposed. The structure of capacitive MEMS power sensor was simulated by Ansys HFSS software.According to the electric and magnetic field distributions on the surface of the MEMS beam, the effective sensing range is determined. The mechanical performance of capacitive sensor was analyzed at the 4W input power to obtain displacement distribution by the Ansys FEM software. The traditional microwave-to-electricity conversion model was first modified. Further, taking into account the signal reflection caused by the increase of capacitance under large input power, a second correction was made. Finally, the output characteristic of the capacitive MEMS power sensor is measured under high power, and the validity of the nonlinear model of the sensor is verified. It has laid a theoretical foundation for the research of high-power capacitive MEMS microwave power sensor. 2. The term of MEMS microwave phase detector performance: A four-port MEMS microwave phase detector based on MEMS power sensor was fabricated based on GaAs MMIC process. It shows that the measurement results of the MEMS microwave phase detector agree well with the calculation results in a complete cycle. The phase-detection sensitivities of the two sensors were about 16.62μV/° and 23.94aF/°, respectively, at a frequency of 10GHz with a power input of 200mW. Furthermore, to fully reveal the application potential of this MEMS microwave phase detector, this paper also carries out phase detection test under high power, and the test results still accord with the relationship of the cosine curve. The capacitive MEMS microwave power sensor is applied in this device to make up for the lack of thermoelectric power sensor for the high-power handling and can expand the dynamic range of the phase detector up to 4W. 3. In term of the MEMS amplitude demodulator : Three kinds of the MEMS amplitude detectors are proposed based on GaAs MMIC process (thermoelectric type, online type and cascade type). These devices utilize the square-law and low-pass characteristics of thermoelectric converters and electrostatic force actuators. Experiments show that the thermoelectric MEMS detector can achieve the carrier frequency of 0.35-10GHz amplitude modulation signal direct demodulation, covering 0-23dBm power detection range. The on-line MEMS amplitude detector has the return loss of better than 20dB and insertion loss of less than 0.5dB at the 0.01-10GHz band. The cascaded amplitude detector has the advantage of high power handling capability and can cover direct demodulation of (0.35-6GHz) RF signals in the power range from 0 to 23 dBm. The manufacture of these three devices is compatible with GaAs MMIC processes. Besides, none of these MEMS detectors has DC power. 4. Reliability issues related to charging injection of dielectric layers for MEMS cantilever switch: A balance-bridge method is proposed to characterize the reliability problem caused by the charge injection in the dielectric layer of the MEMS cantilever switch. First of all, the equivalent circuit model of the balanced bridge is established, and the precision formula of the balanced bridge method is deduced. The vibration mode of the cantilever beam was analyzed by laser Doppler velocimetry (LDV) to ensure the mechanical symmetry of the cantilever switch structure. The electrical symmetry of the cantilever switch structure was analyzed by using a signal function generator and oscilloscope. The charging process under DC voltage is studied. The experimental results show that the accuracy of the balanced bridge method can reach 10Ω/fF. The contact and non-contact charging process can be observed by using this method. The two charging effects can be distinguished by the post-fitting relaxation time and the tensile index factor. The charge in the dielectric layer occurs mainly in the first 1200s. Based on this approach, the dielectric charge process under the RF signal of 26-33dBm at 26GHz was studied, and the corresponding mechanism was analyzed and discussed. The experimental results show that the effect of charging the lower dielectric layer under RF signals is insufficient compared to DC voltage. 5. Design theory and implementation method of the MEMS microwave signal integrated detection system: Design Theory: Firstly, the general formula of n-port signal detection is given through passive network signal superposition and synthesis process. The theoretical method of the integrated microwave signal detection system is deduced from the general formula, which provides the basis for the device structures. Secondly, based on this, the architecture of the two microwave signal integrated detection systems are proposed, and their HFSS structures simulation are carried out to determine the final structure. Implementation Methods: Based on the GaAs MMIC process, two MEMS microwave signal integrated detection systems were fabricated. The two kinds of microwave signal integrated detection system: first, the frequency of the microwave signal is measured by the amplitude ratio and phase comparison method, and the frequency detection has no relation with the power. Secondly, the signal power is detected by the coupling method, and the results are corrected to realize the frequency independent. Two microwave integrated signal detection system using the quadrature dual-channel method to achieve the phase detection. Further two kinds of microwave integrated detection system achieve amplitude demodulation. At last, the S-parameter model of MEMS microwave device and integrated detection system is deduced based on microwave network theory. It provides robust theoretical support for the embedded application in microwave communication system. The MEMS microwave signal integrated detection system realizes the integrated synchronous detection of microwave power, phase, frequency and amplitude modulation signals, and has the advantages of small size, lightweight and low power consumption.
学术讨论
主办单位时间地点报告人报告主题
东南大学 2015年6月 南高院 闫浩 电荷输入可靠性研究
东南大学 2015年6月 南高院 韩居正 三阶互调失真的研究
东南大学 2015年12月 南高院 闫浩 MEMS微波相位检测器的研究
东南大学 2015年12月 南高院 韩居正 宽带双级功分器
东南大学 2016年3月 南高院 闫浩 Temperature sensor and mechanical sensor
东南大学 2016年3月 南高院 韩居正 MEMS相位检测与锁相环
东南大学 2016年9月 南高院 闫浩 MEMS微波信号集成检测
东南大学 2016年12月 南高院 韩居正 MEMS相位检测器中的温度漂移问题
     
学术会议
会议名称时间地点本人报告本人报告题目
IEEE Sensors Nov. 2015 Busan, Korea The phase sensitivity and response time of an X-band dual channel microwave phase detector
IEEE Sensors Nov. 2016 Florida, USA High-power handling capacity and output response of a capacitive microwave power sensor
     
代表作
论文名称
The High-Power up to 1W Characteristics of the Capacitive Microwave Power Sensor with Grounded MEMS
The Phase Sensitivity and Response Time of an X-Band Dual Channel
High-Power up to 4W Characteristics of the Capacitive Microwave Power Sensor with Grounded MEMS Beam
An X -Band Dual Channel Microwave Phase Detector Based on GaAs MMIC Technology
A Dual-Channel MEMS Amplitude Demodulator for On-Line Detection in Radio Relay Station
A Four-Port Microwave Phase Detector at X-band Based on MEMS Power Sensors
High-power handling capacity and output response of a capacitive microwave power sensor
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
时龙兴 正高 教授 博导 东南大学 主任委员
裘安萍 正高 教授 博导 南京理工大学
柏松 正高 研究员 其他 中电集团55所
吴建辉 正高 教授 博导 东南大学
秦明 正高 教授 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
陈洁 副高 副教授 东南大学 秘书