Development Of Reflectivity Temperature-change Measurement System For Radar Absorbing Material

RAM(Radar Absorbing Material) has widely purposes in civil and military applications. RAM is evaluated by its macro characteristic parameter—reflectivity. In order to comprehensive research RAM, it is necessary to investigate complex dielectric constant, permeability and reflectivity. Since the RAM may be used under the range of temperature conditions, so temperature-change measurement is needed to know RAM's temperature characteristics and it can guide us in the RAM research. This thesis is about to establish RAM temperature change measurement system.First, three different hardware architectures of temperature controller have been analysised, in this bases, SOC(System On Chip) ADuC834 is presented in this thesis design, and several temperature control algorithms been screened, the most popular fuzzy logic control algorithm is adopted.This thesis detailed introduced basic theory and method of fuzzy logic temperature controller. Especially well-designed is applied to RTD analog front end circuit and power output circuit. In order to improve the accuracy of system measurement, digital linearization process techniques (Direct Mathematic Method) is applied to RTD results. RTX51 Tiny real-time operating system (RTOS) is introduced in system software design. It allows you to create applications that simultaneously perform multiple functions or tasks. The system task is divided into several tasks, these tasks are flexible scheduled and managed by RTX51 Tiny RTOS. Using this software architecture not only simplified design but also improved stability, reliability and real-time performance.To constant temperature system, heater insulator is very important, because the RAM sample test has special requirement, constant temperature box utilized dismountable and divided design style. At last, constant temperature curves and temperature change curves of three RAM samples has been given. The test result indicated this high precision temperature change measurement system satisfied the predictive parameter index and corresponding function requirements.