光纤温度传感器在微波场测温中的应用

处于强电磁场的环境下，在微波场中温度的测量依然是一个技术难题。介绍了适用于微波场测温的各类光纤温度传感器，阐述了光纤光栅用于温度传感的原理及在微波场中测温的前景与应用。对微波场中测温技术的进一步发展具有一定的参考价值。     

用于人体皮下温度测量的微波辐射计系统可行性研究

目前人体测温主要以红外测温和水银体温计为主,其仅能测量人体表皮温度,针对此现状,以微波辐射测温理论为依据,提出一种中心频率为1.4 GHz的微波辐射计系统,并利用目前消费类电子产品的MMIC芯片设计制作完成。系统硬件模块主要包括高增益放大器模块、带通滤波器模块和平方律检波模块。根据不同温度状态下人体皮下组织的辐射能量,系统测得最终输出电压与温度呈正相关,能够很好地响应皮下温度变化。研究结果表明,基于现有消费类电子产品的芯片可以制作出成本较低的L波段微波辐射计,能跟踪组织层的温度,验证了监测人体内部温度的可行性。     

高精度星载微波定标源黑体温度测量控制系统的设计

微波辐射定标源作为微波辐射计的重要载荷设备,可校准微波辐射计输入亮温度与输出量值间的关系,实现微波辐射计灵敏度、线性度和稳定度等参数的标定。针对辐射源黑体及其测温传感器,设计了一种在轨温度测量与控制电路,用于温度信号的检测与调理、低通滤波、数据采集、温度数据处理以及温度的稳定控制。地面测试与在轨运行均表明,系统满足星载微波辐射计的设计要求,具有高精度、高可靠性的特点。     

微波场中温度传感方法

微波技术是近代科学技术发展的重大成就之一，而微波作为一种新型热源已被广泛应用于化学研究，食品加工，医疗仪器以及材料热处理等行业中．发展极为迅速。在这些应用中，温度显然是个重要的参数，但处于强电磁场的环境下，在微波场中温度的测量依然是一个技术难题。微波场中测温技术进一步改进，将大大推进微波在各行业中的应用。该文简述了微波加热的机理与特点，综述了目前已经实现的微波场中温度测量的方法，并进行了优劣性比较，对微波场中测温技术发展具有一定的参考价值。     

红外线人体测温仪电路的设计

为了适应医学的发展,研究红外线人体测温技术具有实际的意义。阐述了红外线测温原理,对如何减小测温误差进行了讨论,同时进行了红外线人体测温系统设计。在分析红外线传感器和A/D转换对测量精度影响的基础上,选择PM611单元热释电传感器和ICL7106积分式A/D转换器等器件实现了一种误差较小的红外线人体测温电路的设计,达到了预定的设计效果。     

基于单片机的分布式测温系统设计

主要是对多点测温系统的设计与应用进行了研究,利用新型的智能传感器DS18B20的测温原理,设计一种可以实现多点测温并达到精确测量目的温度计。通过键盘和LED显示数码管对系统进行控制和显示。     

射频和微波加工食品的食品工程研究中所用的测温方法

本文对以射频和微波频率加工食品原料用的测温方法进行了论述。讨论了所需要的食品工程研究的若干问题,以及选择温度监测系统的一些重要因素。     

基于LoRa通信的广播电视发射台站温度监测系统设计

本文为在广播电视发射台站实现硬馈等温度监测,开发了一种基于Linux嵌入式的物联网测温系统.温度监测系统分为测温服务器、测温网关、测温节点三部分.低功耗的测温节点采用电池供电,测温网关采用POE供电,经实地测试运行表明该系统满足设计要求,实现了一种远距离,广覆盖的广电物联网应用[1].     

一种实用化实时测温系统的工作波长的最优设计

基于Kirchhoff定律 ,依照测温系统的各主要技术参数与各主要测量指标 (极限灵敏度、测温精度及测温范围 )之间的关系 ,对利用激光并采用钽酸锂热释电探测器作光电转换器件的实用化实时测温系统的工作波长进行了最优化设计。实验表明 ,在测温范围 4 0 0～ 12 0 0℃内 ,测温灵敏度及测温精度均符合设计要求。     

基于矩形谐振腔的介电系数测量装置

物质介电系数的测量对微波能的应用十分重要。文中基于谐振腔微扰法设计了一种结构简单的矩形谐振腔测量装置。通过测温孔的设计,该测量装置在测量物质介电系数的同时还能测量待测物的温度,可以得到不同温度条件下物质的介电系数。频率为2.45 GHz时,采用该装置对几种有机溶剂进行测量,得到了与相关文献一致的结果。     

Thermal model for the local microwave hyperthermia treatment ofbenign prostatic hyperplasia

A system for the noninvasive localized, hyperthermia treatment of benign prostatic hyperplasia was investigated. The system uses a microwave transrectal antenna with a water cooled jacket to achieve localized hyperthermia. The purpose of this study is to model the temperature rise in the prostate and in the surrounding tissue during treatment. The SAR distribution for the transrectal probe is measured in a muscle tissue equivalent phantom. The SAR information is used with a finite element solution of the bioheat transfer equation to give the temperature rise during the treatment. Also the finite element solution is further used to determine the effect of the microwave power, the cooling fluid temperature and the blood perfusion on the tissue temperature rise. The results of the solution are compared to temperature measurements in a canine protocol. It was found that the maximum temperature rise in the tissue during treatment is 44 degrees C at a depth of 2 cm from the rectal mucosa.     

Theoretical and experimental analysis of air cooling forintracavitary microwave hyperthermia applicators

An intracavitary microwave antenna array system has been developed and tested for the hyperthermia treatment of prostate cancer at Thayer School of Engineering and Dartmouth-Witchcock Medical Center. The antenna array consists of a choked dipole antenna inserted into the urethra and a choked dipole antenna eccentrically embedded in a Teflon obturator inserted into the rectum. To prevent unnecessary heating of the healthy tissue that surrounds each applicator, an air cooling system has been incorporated into the rectal applicator. The air cooling system was designed and modeled theoretically using a numerical solution of heat and momentum equations within the applicator, and an analytical solution of the Pennes bioheat equation in tissue surrounding the applicator. The 3D temperature distribution produced by the air-cooled rectal applicator was measured in a perfused canine prostate     

Experimental studies on the use of microwaves for the localized heat treatment of the prostate.

High frequency tumor therapy requests heating of a well defined area, whereas the surroundings should be unaffected. This sort of therapy should be more tolerable than a whole body heating. For this purpose a new developed microwave applicator (433.9 MHz) for local heat application was tested in animals. Using this rectally insertable applicator the prostate of dogs were irradiated. The temperature of the rectum, the urethra and the prostate were measured and recorded using specially developed thermistor probes. The effect of hyperthermia on the prostate and the surrounding tissue was analyzed macroscopically and micromorphologically. It was shown that local heating of the prostate of dogs is possible. The induced damages of the prostate and surrounding tissue is not severe enough to be untolerable.     

集总参数微波多工器的设计

介绍了集总参数LC微波多工器的设计原理和MicrowaveOffice在微波多工器设计中的应用。从工程实践的角度提供了一种易调试、低成本LC微波多工器的设计模型,该模型主要采用高通滤波器和低通滤波器相互组合来实现有用信号的合并与分离,使设计简单易调,适合于批量生产。给出了集总参数微波多工器软件设计的仿真效果和设计模块的测试结果。从测试结果可以看出,主要通道的相对群时延特性和回波损耗特性与仿真结果符合较好。     

微波无源网络的创新设计性实验探索

本文分析了微波实验课缺乏创新设计性实验的原因,提出了改革方案——微波无源网络创新设计性实验。笔者较详细的介绍了实验过程中的设计、仿真、制作和测试等各个环节,并讨论了实验测试结果,给出了实验成本。实践表明,本文提出的微波实验课改革方案具有良好的教学效果。     

Microwave frequency detector at X-band using GaAs MMIC technology

The design,fabrication,and experimental results of an MEMS microwave frequency detector are presented for the first time.The structure consists of a microwave power divider,two CPW transmission lines,a microwave power combiner,an MEMS capacitive power sensor and a thermopile.The detector has been designed and fabricated on GaAs substrate using the MMIC process at the X-band successfully.The MEMS capacitive power sensor is used for detecting the high power signal,while the thermopile is used for detecting the low power signal.Signals of 17 and 10 dBm are measured over the X-band.The sensitivity is 0.56 MHz/fF under 17 dBm by the capacitive power sensor,and 6.67 MHz//μV under 10 dBm by the thermopile.respectively.The validity of the presented design has been confirmed by the experiment.     

Full-wave CAD of a rectangular waveguide filter with integratedcoaxial excitation

Coaxial waveguides are very commonly used in many microwave subsystems for the connection of various components. Significant size reduction could, therefore, be achieved by integrating the design of the coaxial transition in the computer-aided design (CAD) of microwave filters. In this context, we first discuss in this paper a coaxial transition, which can be efficiently designed interactively using an accurate and efficient CAD procedure. The key elements of the CAD tool developed are then described and a specific example of a microwave filter is discussed. In addition to theory, measured results are also presented, thereby fully validating both the CAD tool and the structures proposed     

基于微波均衡器测量数据库的网络优化设计

基于微波幅度均衡器测量数据库的互联子结构网络计算机辅助设计的方法结合了数据实验测量的精确性和计算机大容量、高速运算的优点，它包括子结构设计、测量数据库的建立、子结构互联网络理论和优化算法设计等多步骤。该方法在微波幅度均衡器设计、调试中得到验证和应用，具有实际的工程价值。     

一种紧凑型大功率微波固态源

传统的微波源主要由行波管、磁控管、返波管等电真空器件实现,但因其工作电压高、功耗大、体积大,导致在使用安全性、利用效率和便携性等方面存在不足。而微波固态源由于具有效率高、谐波抑制性能好、稳定性高等优点,正逐步替代传统微波源,有着很好的发展空间。设计了一种紧凑型大功率微波固态源,采用锁相环作为信源,通过三级功放级联对微波信号进行逐级放大,最终输出频率为915 MHz、功率为300 W 的微波信号。测试结果表明该固态源的工作效率≥70%,二次谐波抑制≤-40 dBc,三次谐波抑制≤-50 dBc。该设计在微波加热和解冻等方面具有很好的应用前景。     

微波取样锁相频率合成器的设计

阐述了微波接收机中的相位噪声概念及本振源频率不稳定度的实际测量参数,并简要介绍了频率合成技术和锁相环路工作原理.针对卫星电视接收机中微波高稳定本振源的要求,重点研究了取样锁相频率合成器电路的优化设计及性能.